Digital Potentiometers Design Guide
Supporting digital potentiometer applications, including: mechanical
potentiometer replacement, amplifiers with offset and trimming,
band pass filtering with offset and gain trimming, programmable filter,
Wheatstone bridge trimming and general embedded system design techniques.
Design ideas in this guide use the following devices. A complete device list and corresponding data sheets for
these products can be found at www.microchip.com.
www.microchip.com/analog
Analog and Interface Product Solutions
6-bit 7-bit 8-bit
Single Single Dual Quad Single Dual Quad
MCP401X
MCP402X
MCP401X
MCP40D1X
MCP413X
MCP414X
MCP453X
MCP423X
MCP424X
MCP463X
MCP464X
MCP433X
MCP434X
MCP443X
MCP444X
MCP415X
MCP416X
MCP455X
MCP456X
MCP425X
MCP426X
MCP465X
MCP466X
MCP435X
MCP436X
MCP445X
MCP446X
2 Digital Potentiometer Design Guide
Microchip’s Family of Digital Potentiometers
Microchip offers a range of devices that allow the customer
to select a device that is a best fit for their application. Some
of the selection options include:
■ A wide range of resistor values
– RAB resistance (typical) from 2.1 k to 100 k
■ Step resolution
– 6-bit
– 7-bit
– 8-bit
■ Serial interfaces
– Up/Down
– SPI
– I2C™
■ Memory types
– Volatile
– Non-volatile
■ Resistor network configurations
– Potentiometer (resistor divider)
– Rheostat (variable resistor)
■ Single, dual and quad potentiometer options
■ Package options
■ Special features
– Shutdown mode
– WiperLock™ technology
■ Low voltage, Low power options
Resistor sizes and resolutions allow the designer to select
the step resistance and number of steps. For the device with
the resistance (RAB) equal to 2.1 k, there are 64 steps (63
resistors), so the step resistance (RS) equals RAB/63 (or
33.33). For a 5 k device with 257 steps (256 resistors), a
step resistance (RS) equals RAB/256 = 19.53. Now at the
other end of the spectrum, for the device with the resistance
(RAB) equal to 50 k, there are 64 steps (63 resistors), so
the step resistance (RS) equals RAB/63 (or 793.65).
The serial interface options allow the designer to easily
integrate the device into the application. For some
applications the simple Up/Down interface will be adequate.
For devices with higher resolution (7-bit, 8-bit) being able
to directly write/read the wiper register is desirable. This
is supported with SPI and I2C interfaces. SPI is simpler to
implement, but I2C uses only 2 signals (pins) and supports
multiple devices on the serial bus without additional pins.
The availability of both volatile and non-volatile devices
allows the designer flexibility in optimizing the application.
Some applications may use the digital potentiometer as a
replacement for a mechanical potentiometer. In this case, a
non-volatile device with the serial interface connecting to the
test hardware interface allows a low cost device with low cost
manufacturing.
Resistor network configurations allow the package size/
cost to be minimized for the desired functionality. If a
variable resistor (rheostat) with one terminal tied to ground
is desired, then only one resistor terminal (the wiper) needs
to be implemented. In the MCP4017/18/19 family, this
configuration is shown in the MCP4019 and allows the
functionality to be achieved in a low-cost SC70-5 package.
Dual and quad digital potentiometer resistor networks
are closely matched, due to residing on the same silicon.
Matched components allow customers to achieve better
system performance in some applications
Packaging options allow customers to address their system
requirement trade-offs including device cost, board area, and
manufacturing sites (surface mount vs. thru-hole). Packages
include 3x3 mm SOT-23 and DFN packages, 3x2 mm DFN
package and tiny SC70 packages.
Digital Potentiometer Solutions
Digital Potentiometer Design Guide 3
Low Power Applications
Many applications are power sensitive. This is because they
are battery powered or design goals on the power supply.
Microchip Technology’s digital potentiometer families are
low power, with the maximum IDD as low as 1 µA in some
devices. This current is when the serial interface is inactive
and a non-volatile memory write cycle is not active. This
current does not include any current through the resistor
network (the A, B and W pins).
The 1 uA max IDD devices include the MCP4011, MCP4012,
MCP4013, MCP4014, MCP4021, MCP4022, MCP4023,
MCP4024, MCP41010, MCP41050, MCP41100, MCP42010,
MCP42050 and MCP42100. Currently all other devices have
a max IDD of 5 µA.
A capability is given in many of the devices to shut down
the resistor network, that is disconnect the resistor network
from the circuit. This can substantially reduce the current
of the system. This shut down mode may be achieved by a
hardware pin (SHDN) or via software through the Terminal
Control register(s). The software shutdown allows devices to
retain this capability while being packaged in the smallest
package since the SHDN pin is not present.
The hardware shutdown forces the resistor network into a
defined condition where the resistor network is disconnected
from the Terminal A pin and the Wiper value is forced to 00h
(Wiper connected to Terminal B). The Wiper register retains
it value so that when shutdown is exited the wiper returns to
it’s previous position.
Devices with Low Power Operation
Device
Serial
Interface
Volatile (Vol)
Non-Volatile (NV)
# RS Resistors
Rs Ω (typ.)
Zero-Scale/
Full-Scale(3)
# of Channels
WiperLock™
Technology
HV Commands
Shutdown
Mode
Configuration
Voltage
Range
# of Pins
Packages
IDD max (μA)(5)
MCP4011(1) U/D Vol 63 33.3/79.4/158.7/793.7 Y/Y 1 N Y(9) N Pot 1.8V to 5.5V(6) 8 SOIC, MSOP, DFN 1
MCP4012(1) U/D Vol 63 33.3/79.4/158.7/793.7 Y/Y 1 N Y(9) N Rheo 1.8V to 5.5V(6) 6 SOT-23 1
MCP4013(1) U/D Vol 63 33.3/79.4/158.7/793.7 Y/Y 1 N Y(9) N Pot(7) 1.8V to 5.5V(6) 6 SOT-23 1
MCP4014(1) U/D Vol 63 33.3/79.4/158.7/793.7 Y/Y 1 N Y(9) N Rheo(7) 1.8V to 5.5V(6) 5 SOT-23 1
MCP4021(1) U/D NV 63 33.3/79.4/158.7/793.7 Y/Y 1 Y Y N Pot 2.7V to 5.5V 8 SOIC, MSOP, DFN 1
MCP4022(1) U/D NV 63 33.3/79.4/158.7/793.7 Y/Y 1 Y Y N Rheo 2.7V to 5.5V 6 SOT-23 1
MCP4023(1) U/D NV 63 33.3/79.4/158.7/793.7 Y/Y 1 Y Y N Pot(7) 2.7V to 5.5V 6 SOT-23 1
MCP4024(1) U/D NV 63 33.3/79.4/158.7/793.7 Y/Y 1 Y Y N Rheo(7) 2.7V to 5.5V 5 SOT-23 1
MCP41010 SPI Vol 256 39.1 Y/N(4) 1 N N N Pot 2.7V to 5.5V 8 PDIP, SOIC 1
MCP41050 SPI Vol 256 195.3 Y/N(4) 1 N N N Pot 2.7V to 5.5V 8 PDIP, SOIC 1
MCP41100 SPI Vol 256 390.6 Y/N(4) 1 N N N Pot 2.7V to 5.5V 8 PDIP, SOIC 1
MCP42010 SPI Vol 256 39.1 Y/N(4) 2 N N Y Pot 2.7V to 5.5V 14 PDIP, SOIC, TSSOP 1
MCP42050 SPI Vol 256 195.3 Y/N(4) 2 N N Y Pot 2.7V to 5.5V 14 PDIP, SOIC, TSSOP 1
MCP42100 SPI Vol 256 390.6 Y/N(4) 2 N N Y Pot 2.7V to 5.5V 14 PDIP, SOIC, TSSOP 1
1. Resistor options are: -202 (2.1 k), -502 (5.0 k), -103 (10.0 k), and -503 (50.0 k).
2. Resistor options are: -502 (5.0 k), -103 (10.0 k), 503 (50.0 k), and -104 (100.0 k).
3. Zero-scale allows the wiper to “directly” connect to Terminal B, while full-scale allows the wiper to “directly” connect to Terminal A.
4. There is one RS resistor between the maximum wiper value and Terminal A.
5. This current is with the serial interface inactive, and not during an EEPROM write cycle (for non-volatile devices).
6. The serial interface has been tested to 1.8V, the device’s analog characteristics (resistor) have been tested from 2.7V to 5.5V. Review the device’s characterization graphs for information on analog performance between
1.8Vand 2.7V.
7. One of the terminal pins (A or B) is internally connected to ground, due to the limitation of the number of pins on the package.
8. Shutdown support via software (TCON register(s)). If device has SHDN pin, software shutdown also fuctions.
9. High voltage command support is for compatibility with the corresponding non-volatile version of the device.
Digital Potentiometer Solutions
The software shutdown allows control to each of the resistor
network terminal pins. Each resistor network has 4-bit in
a TCON register. A bit for each terminal pin (A, B and W)
and one bit that mimics the hardware shutdown state (the
resistor network is disconnected from the Terminal A pin and
the Wiper value is forced to 00h). This allows the application
to completely control the currents through the digital
potentiometers resistor network(s).
The software shutdown is more flexible then the hardware
shutdown pin, and is available on devices where due
to package selection a hardware shutdown pin was not
implemented.
Normal vs. Shutdown Mode
4 Digital Potentiometer Design Guide
Low Voltage Applications
Some applications require a low operating voltage. Microchip
offers most of their volatile memory devices specified down
to 1.8V for their digital operation. The analog performance
at this low voltage is not specified, but is characterized. For
many applications this may be acceptable.
Digital Potentiometer Solutions
Devices that Support Low Voltage (1.8V) Operation
Device
Serial
Interface
Volatile (Vol)
Non-Volatile (NV)
# RS Resistors
Rs Ω (typ.)
Zero-Scale/
Full-Scale(3)
# of Channels
WiperLock™
Technology
HV Commands
Shutdown
Mode
Configuration
Voltage
Range
# of Pins
Packages
IDD max (μA)(5)
MCP4011(1) U/D Vol 63 33.3/79.4/158.7/793.7 Y/Y 1 N Y(9) N Pot 1.8V to 5.5V(6) 8 SOIC, MSOP, DFN 1
MCP4012(1) U/D Vol 63 33.3/79.4/158.7/793.7 Y/Y 1 N Y(9) N Rheo 1.8V to 5.5V(6) 6 SOT-23 1
MCP4013(1) U/D Vol 63 33.3/79.4/158.7/793.7 Y/Y 1 N Y(9) N Pot(7) 1.8V to 5.5V(6) 6 SOT-23 1
MCP4014(1) U/D Vol 63 33.3/79.4/158.7/793.7 Y/Y 1 N Y(9) N Rheo(7) 1.8V to 5.5V(6) 5 SOT-23 1
MCP4017(2) I2C Vol 127 39.4/78.7/393.7/787.4 Y/Y 1 N N N Rheo 1.8V to 5.5V(6) 6 SC70 5
MCP4018(2) I2C Vol 127 39.4/78.7/393.7/787.4 Y/Y 1 N N N Pot(7) 1.8V to 5.5V(6) 6 SC70 5
MCP4019(2) I2C Vol 127 39.4/78.7/393.7/787.4 Y/Y 1 N N N Rheo(7) 1.8V to 5.5V(6) 5 SC70 5
MCP40D17(2) I2C Vol 127 39.4/78.7/393.7/787.4 Y/Y 1 N N N Rheo 1.8V to 5.5V(6) 6 SC70 5
MCP40D18(2) I2C Vol 127 39.4/78.7/393.7/787.4 Y/Y 1 N N N Pot(7) 1.8V to 5.5V(6) 6 SC70 5
MCP40D19(2) I2C Vol 127 39.4/78.7/393.7/787.4 Y/Y 1 N N N Rheo(7) 1.8V to 5.5V(6) 5 SC70 5
MCP4131(2) SPI Vol 128 39.1/78.1/390.6/781.3 Y/Y 1 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 8 PDIP, SOIC, MSOP, DFN 5
MCP4132(2) SPI Vol 128 39.1/78.1/390.6/781.3 Y/Y 1 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 8 PDIP, SOIC, MSOP, DFN 5
MCP4151(2) SPI Vol 256 19.5/39.1/195.3/390.6 Y/Y 1 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 8 PDIP, SOIC, MSOP, DFN 5
MCP4152(2) SPI Vol 256 19.5/39.1/195.3/390.6 Y/Y 1 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 8 PDIP, SOIC, MSOP, DFN 5
MCP4231(2) SPI Vol 128 39.1/78.1/390.6/781.3 Y/Y 2 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 14, 16 PDIP, SOIC, TSSOP, QFN 5
MCP4232(2) SPI Vol 128 39.1/78.1/390.6/781.3 Y/Y 2 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 10 MSOP, DFN 5
MCP4251(2) SPI Vol 256 19.5/39.1/195.3/390.6 Y/Y 2 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 14, 16 PDIP, SOIC, TSSOP, QFN 5
MCP4252(2) SPI Vol 256 19.5/39.1/195.3/390.6 Y/Y 2 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 10 MSOP, DFN 5
MCP4331(2) SPI Vol 128 39.1/78.1/390.6/781.3 Y/Y 4 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 20 TSSOP, QFN 5
MCP4332(2) SPI Vol 128 39.1/78.1/390.6/781.3 Y/Y 4 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 14 TSSOP 5
MCP4351(2) SPI Vol 256 19.5/39.1/195.3/390.6 Y/Y 4 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 20 TSSOP, QFN 5
MCP4352(2) SPI Vol 256 19.5/39.1/195.3/390.6 Y/Y 4 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 14 TSSOP 5
MCP4431(2) I2C Vol 128 39.1/78.1/390.6/781.3 Y/Y 4 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 20 TSSOP, QFN 5
MCP4432(2) I2C Vol 128 39.1/78.1/390.6/781.3 Y/Y 4 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 14 TSSOP 5
MCP4451(2) I2C Vol 256 19.5/39.1/195.3/390.6 Y/Y 4 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 20 TSSOP, QFN 5
MCP4452(2) I2C Vol 256 19.5/39.1/195.3/390.6 Y/Y 4 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 14 TSSOP 5
MCP4531(2) I2C Vol 128 39.1/78.1/390.6/781.3 Y/Y 1 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 8 MSOP, DFN 5
MCP4532(2) I2C Vol 128 39.1/78.1/390.6/781.3 Y/Y 1 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 8 MSOP, DFN 5
MCP4551(2) I2C Vol 256 19.5/39.1/195.3/390.6 Y/Y 1 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 8 MSOP, DFN 5
MCP4552(2) I2C Vol 256 19.5/39.1/195.3/390.6 Y/Y 1 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 8 MSOP, DFN 5
MCP4631(2) I2C Vol 128 39.1/78.1/390.6/781.3 Y/Y 2 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 14, 16 TSSOP, QFN 5
MCP4632(2) I2C Vol 128 39.1/78.1/390.6/781.3 Y/Y 2 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 10 MSOP, DFN 5
MCP4651(2) I2C Vol 256 19.5/39.1/195.3/390.6 Y/Y 2 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 14, 16 TSSOP, QFN 5
MCP4652(2) I2C Vol 256 19.5/39.1/195.3/390.6 Y/Y 2 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 10 MSOP, DFN 5
1. Resistor options are: -202 (2.1 k), -502 (5.0 k), -103 (10.0 k), and -503 (50.0 k).
2. Resistor options are: -502 (5.0 k), -103 (10.0 k), 503 (50.0 k), and -104 (100.0 k).
3. Zero-scale allows the wiper to “directly” connect to Terminal B, while full-scale allows the wiper to “directly” connect to Terminal A.
4. There is one RS resistor between the maximum wiper value and Terminal A.
5. This current is with the serial interface inactive, and not during an EEPROM write cycle (for non-volatile devices).
6. The serial interface has been tested to 1.8V, the device’s analog characteristics (resistor) have been tested from 2.7V to 5.5V. Review the device’s characterization graphs for information on analog performance between
1.8Vand 2.7V.
7. One of the terminal pins (A or B) is internally connected to ground, due to the limitation of the number of pins on the package.
8. Shutdown support via software (TCON register(s)). If device has SHDN pin, software shutdown also fuctions.
9. High voltage command support is for compatibility with the corresponding non-volatile version of the device.
1.8V operational devices are all volatile devices except
for the MCP41010, MCP41050, MCP41100, MCP42010,
MCP42050 and MCP42100 devices.
Digital Potentiometer Design Guide 5
Digital Potentiometer Solutions
Package Area (mm2) Comment
MSOP ~14.7
DFN (3x3) ~9 39% Smaller than MSOP
SOT-23 ~8.3 44% Smaller than MSOP
DFN (2x3) ~6 59% Smaller than MSOP
33% Smaller than DFN 3x3
SC70 ~4.2 71% Smaller than MSOP
55% Smaller than DFN 3x3
30% Smaller than DFN 2x3
SOT-23
3 mm
2.95 mm
DFN
3 mm
3 mm DFN
3 mm
2 mm
SC70
2.1 mm
2 mm
MSOP
4.9 mm
3 mm
Small Footprint Applications
Some applications have package size limitations and require
devices with the smallest footprint possible. Microchip offers
several devices in small footprint packages. These packages
include 8-pin DFN (3x3 mm and 2x3 mm), 5 and 6-pin SOT-23
and 5 and 6-pin SC70 packages.
Small Footprint Devices
Devices with Small Footprints
Device
Serial
Interface
Volatile (Vol)
Non-Volatile (NV)
# RS Resistors
Rs Ω (typ.)
Zero-Scale/
Full-Scale(3)
# of Channels
WiperLock™
Technology
HV Commands
Shutdown
Mode
Configuration
Voltage
Range
# of Pins
Packages
IDD max (μA)(5)
MCP4011(1) U/D Vol 63 33.3/79.4/158.7/793.7 Y/Y 1 N Y(9) N Pot 1.8V to 5.5V(6) 8 DFN 2x3 1
MCP4012(1) U/D Vol 63 33.3/79.4/158.7/793.7 Y/Y 1 N Y(9) N Rheo 1.8V to 5.5V(6) 6 SOT 1
MCP4013(1) U/D Vol 63 33.3/79.4/158.7/793.7 Y/Y 1 N Y(9) N Pot(7) 1.8V to 5.5V(6) 6 SOT 1
MCP4014(1) U/D Vol 63 33.3/79.4/158.7/793.7 Y/Y 1 N Y(9) N Rheo(7) 1.8V to 5.5V(6) 5 SOT 1
MCP4021(1) U/D NV 63 33.3/79.4/158.7/793.7 Y/Y 1 Y Y N Pot 2.7V to 5.5V 8 DFN 2x3 1
MCP4022(1) U/D NV 63 33.3/79.4/158.7/793.7 Y/Y 1 Y Y N Rheo 2.7V to 5.5V 6 SOT 1
MCP4023(1) U/D NV 63 33.3/79.4/158.7/793.7 Y/Y 1 Y Y N Pot(7) 2.7V to 5.5V 6 SOT 1
MCP4024(1) U/D NV 63 33.3/79.4/158.7/793.7 Y/Y 1 Y Y N Rheo(7) 2.7V to 5.5V 5 SOT 1
MCP4017(2) I2C Vol 127 39.4/78.7/393.7/787.4 Y/Y 1 N N N Rheo 1.8V to 5.5V(6) 6 SC70 5
MCP4018(2) I2C Vol 127 39.4/78.7/393.7/787.4 Y/Y 1 N N N Pot(7) 1.8V to 5.5V(6) 6 SC70 5
MCP4019(2) I2C Vol 127 39.4/78.7/393.7/787.4 Y/Y 1 N N N Rheo(7) 1.8V to 5.5V(6) 5 SC70 5
MCP40D17(2) I2C Vol 127 39.4/78.7/393.7/787.4 Y/Y 1 N N N Rheo 1.8V to 5.5V(6) 6 SC70 5
MCP40D18(2) I2C Vol 127 39.4/78.7/393.7/787.4 Y/Y 1 N N N Pot(7) 1.8V to 5.5V(6) 6 SC70 5
MCP40D19(2) I2C Vol 127 39.4/78.7/393.7/787.4 Y/Y 1 N N N Rheo(7) 1.8V to 5.5V(6) 5 SC70 5
MCP4131(2) SPI Vol 128 39.1/78.1/390.6/781.3 Y/Y 1 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 8 DFN 3x3 5
MCP4132(2) SPI Vol 128 39.1/78.1/390.6/781.3 Y/Y 1 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 8 DFN 3x3 5
MCP4141(2) SPI NV 128 39.1/78.1/390.6/781.3 Y/Y 1 Y Y Y(8) Pot 2.7V to 5.5V 8 DFN 3x3 5
MCP4142(2) SPI NV 128 39.1/78.1/390.6/781.3 Y/Y 1 Y Y Y(8) Rheo 2.7V to 5.5V 8 DFN 3x3 5
MCP4151(2) SPI Vol 256 19.5/39.1/195.3/390.6 Y/Y 1 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 8 DFN 3x3 5
MCP4152(2) SPI Vol 256 19.5/39.1/195.3/390.6 Y/Y 1 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 8 DFN 3x3 5
MCP4161(2) SPI NV 256 19.5/39.1/195.3/390.6 Y/Y 1 Y Y Y(8) Pot 2.7V to 5.5V 8 DFN 3x3 5
MCP4162(2) SPI NV 256 19.5/39.1/195.3/390.6 Y/Y 1 Y Y Y(8) Rheo 2.7V to 5.5V 8 DFN 3x3 5
MCP4531(2) I2C Vol 128 39.1/78.1/390.6/781.3 Y/Y 1 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 8 DFN 3x3 5
MCP4532(2) I2C Vol 128 39.1/78.1/390.6/781.3 Y/Y 1 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 8 DFN 3x3 5
MCP4541(2) I2C NV 128 39.1/78.1/390.6/781.3 Y/Y 1 Y Y Y(8) Pot 2.7V to 5.5V 8 DFN 3x3 5
MCP4542(2) I2C NV 128 39.1/78.1/390.6/781.3 Y/Y 1 Y Y Y(8) Rheo 2.7V to 5.5V 8 DFN 3x3 5
MCP4551(2) I2C Vol 256 19.5/39.1/195.3/390.6 Y/Y 1 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 8 DFN 3x3 5
MCP4552(2) I2C Vol 256 19.5/39.1/195.3/390.6 Y/Y 1 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 8 DFN 3x3 5
MCP4561(2) I2C NV 256 19.5/39.1/195.3/390.6 Y/Y 1 Y Y Y(8) Pot 2.7V to 5.5V 8 DFN 3x3 5
MCP4562(2) I2C NV 256 19.5/39.1/195.3/390.6 Y/Y 1 Y Y Y(8) Rheo 2.7V to 5.5V 8 DFN 3x3 5
1. Resistor options are: -202 (2.1 k), -502 (5.0 k), -103 (10.0 k), and -503 (50.0 k).
2. Resistor options are: -502 (5.0 k), -103 (10.0 k), 503 (50.0 k), and -104 (100.0 k).
3. Zero-scale allows the wiper to “directly” connect to Terminal B, while full-scale allows the wiper to “directly” connect to Terminal A.
4. There is one RS resistor between the maximum wiper value and Terminal A.
5. This current is with the serial interface inactive, and not during an EEPROM write cycle (for non-volatile devices).
6. The serial interface has been tested to 1.8V, the device’s analog characteristics (resistor) have been tested from 2.7V to 5.5V. Review the device’s characterization graphs for information on analog performance between
1.8Vand 2.7V.
7. One of the terminal pins (A or B) is internally connected to ground, due to the limitation of the number of pins on the package.
8. Shutdown support via software (TCON register(s)). If device has SHDN pin, software shutdown also fuctions.
9. High voltage command support is for compatibility with the corresponding non-volatile version of the device.
6 Digital Potentiometer Design Guide
This inhibits accidental modification of the wiper setting,
as long as the high voltage is not present to the digital
potentiometer during normal operation.
Many of the non-volatile devices also have some bytes of
general purpose EEPROM memory available. This could be
used to store system information, such as calibration codes,
manufacture date, serial number or user information.
Non-Volatile Applications
Non-volatile devices allow the desired wiper position to be
saved through a device power down or brown-out condition.
When the device power is restored, the wiper value is loaded
with the wiper value stored in the non-volatile register.
This is useful for both applications where the wiper value is
programmed once and never changed (system calibration) as
well as applications where the last user setting is saved on
system powerdown (such as a volume setting).
Mechanical trim pots have been used for device calibration
to optimize the system performance. Digital potentiometers
can now be a better solution due to reliability and total cost.
Non-volatile memory versions allow the device to power on to
the desired wiper setting. Non-volatile devices have a feature
which can be used to ensure that this wiper value is not
changed in the system.
WiperLock Technology is the method that allows Microchips
non-volatile devices to ensure that once the non-volatile
wiper is “locked” the wiper setting (volatile and non-volatile)
can not be modified except with “High Voltage” commands.
WiperLock™ Technology Operation Example (Up/Down Interface)
Digital Potentiometer Solutions
Devices with Non-Volatile Memory
Device
Serial
Interface
Volatile (Vol)
Non-Volatile (NV)
# RS Resistors
Rs Ω (typ.)
Zero-Scale/
Full-Scale(3)
# of Channels
WiperLock™
Technology/
HV Commands
General Purpose
EEPROM (bytes)
Shutdown
Mode
Configuration
Voltage
Range
# of Pins
Packages
IDD max (μA)(5)
MCP4021(1) U/D NV 63 33.3/79.4/158.7/793.7 Y/Y 1 Y – N Pot 2.7V to 5.5V 8 SOIC, MSOP, DFN 1
MCP4022(1) U/D NV 63 33.3/79.4/158.7/793.7 Y/Y 1 Y – N Rheo 2.7V to 5.5V 6 SOT-23 1
MCP4023(1) U/D NV 63 33.3/79.4/158.7/793.7 Y/Y 1 Y – N Pot(7) 2.7V to 5.5V 6 SOT-23 1
MCP4024(1) U/D NV 63 33.3/79.4/158.7/793.7 Y/Y 1 Y – N Rheo(7) 2.7V to 5.5V 5 SOT-23 1
MCP4141(2) SPI NV 128 39.1/78.1/390.6/781.3 Y/Y 1 Y 10 Y(8) Pot 2.7V to 5.5V 8 PDIP, SOIC, MSOP, DFN 5
MCP4142(2) SPI NV 128 39.1/78.1/390.6/781.3 Y/Y 1 Y 10 Y(8) Rheo 2.7V to 5.5V 8 PDIP, SOIC, MSOP, DFN 5
MCP4161(2) SPI NV 256 19.5/39.1/195.3/390.6 Y/Y 1 Y 10 Y(8) Pot 2.7V to 5.5V 8 PDIP, SOIC, MSOP, DFN 5
MCP4162(2) SPI NV 256 19.5/39.1/195.3/390.6 Y/Y 1 Y 10 Y(8) Rheo 2.7V to 5.5V 8 PDIP, SOIC, MSOP, DFN 5
MCP4241(2) SPI NV 128 39.1/78.1/390.6/781.3 Y/Y 2 Y 10 Y(8) Pot 2.7V to 5.5V 14, 16 PDIP, SOIC, TSSOP, QFN 5
MCP4242(2) SPI NV 128 39.1/78.1/390.6/781.3 Y/Y 2 Y 10 Y(8) Rheo 2.7V to 5.5V 10 MSOP, DFN 5
MCP4261(2) SPI NV 256 19.5/39.1/195.3/390.6 Y/Y 2 Y 10 Y(8) Pot 2.7V to 5.5V 14, 16 PDIP, SOIC, TSSOP, QFN 5
MCP4262(2) SPI NV 256 19.5/39.1/195.3/390.6 Y/Y 2 Y 10 Y(8) Rheo 2.7V to 5.5V 10 MSOP, DFN 5
MCP4341(2) SPI NV 128 39.1/78.1/390.6/781.3 Y/Y 4 Y 5 Y(8) Pot 2.7V to 5.5V 20 TSSOP, QFN 5
MCP4342(2) SPI NV 128 39.1/78.1/390.6/781.3 Y/Y 4 Y 5 Y(8) Rheo 2.7V to 5.5V 14 TSSOP 5
MCP4361(2) SPI NV 256 19.5/39.1/195.3/390.6 Y/Y 4 Y 5 Y(8) Pot 2.7V to 5.5V 20 TSSOP, QFN 5
MCP4362(2) SPI NV 256 19.5/39.1/195.3/390.6 Y/Y 4 Y 5 Y(8) Rheo 2.7V to 5.5V 14 TSSOP 5
MCP4441(2) I2C NV 128 39.1/78.1/390.6/781.3 Y/Y 4 Y 5 Y(8) Pot 2.7V to 5.5V 20 TSSOP, QFN 5
MCP4442(2) I2C NV 128 39.1/78.1/390.6/781.3 Y/Y 4 Y 5 Y(8) Rheo 2.7V to 5.5V 14 TSSOP 5
MCP4461(2) I2C NV 256 19.5/39.1/195.3/390.6 Y/Y 4 Y 5 Y(8) Pot 2.7V to 5.5V 20 TSSOP, QFN 5
MCP4462(2) I2C NV 256 19.5/39.1/195.3/390.6 Y/Y 4 Y 5 Y(8) Rheo 2.7V to 5.5V 14 TSSOP 5
MCP4541(2) I2C NV 128 39.1/78.1/390.6/781.3 Y/Y 1 Y 10 Y(8) Pot 2.7V to 5.5V 8 MSOP, DFN 5
MCP4542(2) I2C NV 128 39.1/78.1/390.6/781.3 Y/Y 1 Y 10 Y(8) Rheo 2.7V to 5.5V 8 MSOP, DFN 5
MCP4561(2) I2C NV 256 19.5/39.1/195.3/390.6 Y/Y 1 Y 10 Y(8) Pot 2.7V to 5.5V 8 MSOP, DFN 5
MCP4562(2) I2C NV 256 19.5/39.1/195.3/390.6 Y/Y 1 Y 10 Y(8) Rheo 2.7V to 5.5V 8 MSOP, DFN 5
MCP4641(2) I2C NV 128 39.1/78.1/390.6/781.3 Y/Y 2 Y 10 Y(8) Pot 2.7V to 5.5V 14, 16 TSSOP, QFN 5
MCP4642(2) I2C NV 128 39.1/78.1/390.6/781.3 Y/Y 2 Y 10 Y(8) Rheo 2.7V to 5.5V 10 MSOP, DFN 5
MCP4661(2) I2C NV 256 19.5/39.1/195.3/390.6 Y/Y 2 Y 10 Y(8) Pot 2.7V to 5.5V 14, 16 TSSOP, QFN 5
MCP4662(2) I2C NV 256 19.5/39.1/195.3/390.6 Y/Y 2 Y 10 Y(8) Rheo 2.7V to 5.5V 10 MSOP, DFN 5
1. Resistor options are: -202 (2.1 k), -502 (5.0 k), -103 (10.0 k), and -503 (50.0 k).
2. Resistor options are: -502 (5.0 k), -103 (10.0 k), 503 (50.0 k), and -104 (100.0 k).
3. Zero-scale allows the wiper to “directly” connect to Terminal B, while full-scale allows the wiper to “directly” connect to Terminal A.
4. There is one RS resistor between the maximum wiper value and Terminal A.
5. This current is with the serial interface inactive, and not during an EEPROM write cycle (for non-volatile devices).
6. The serial interface has been tested to 1.8V, the device’s analog characteristics (resistor) have been tested from 2.7V to 5.5V. Review the device’s characterization graphs for information on analog performance between
1.8Vand 2.7V.
7. One of the terminal pins (A or B) is internally connected to ground, due to the limitation of the number of pins on the package.
8. Shutdown support via software (TCON register(s)). If device has SHDN pin, software shutdown also fuctions.
9. High voltage command support is for compatibility with the corresponding non-volatile version of the device.
Digital Potentiometer Design Guide 7
Digital Potentiometer Solutions
Serial Interfaces
Microchip currently offers devices with one of the following
three serial interfaces:
■ An Up/Down interface
■ An SPI interface
■ An I2C interface
Increment
Decrement
Up/Down Interface
This is an easy to implement interface that requires two pins
and can be implemented with minimal software overhead.
This interface is also easy for test systems when using
the non-volatile devices as replacements for mechanical
potentiometers.
High voltage commands require the CS pin forced to the
VIHH voltage, instead of the VIL voltage. In this state, the
WiperLock Technology bit can be enabled and disabled.
Devices with Up/Down Interface
Device
Serial
Interface
Volatile (Vol)
Non-Volatile (NV)
# RS Resistors
Rs Ω (typ.)
Zero-Scale/
Full-Scale(3)
# of Channels
WiperLock™
Technology
HV Commands
Shutdown
Mode
Configuration
Voltage
Range
# of Pins
Packages
IDD max (μA)(5)
MCP4011(1) U/D Vol 63 33.3/79.4/158.7/793.7 Y/Y 1 N Y(9) N Pot 1.8V to 5.5V(6) 8 DFN 2x3 1
MCP4012(1) U/D Vol 63 33.3/79.4/158.7/793.7 Y/Y 1 N Y(9) N Rheo 1.8V to 5.5V(6) 6 SOT 1
MCP4013(1) U/D Vol 63 33.3/79.4/158.7/793.7 Y/Y 1 N Y(9) N Pot(7) 1.8V to 5.5V(6) 6 SOT 1
MCP4014(1) U/D Vol 63 33.3/79.4/158.7/793.7 Y/Y 1 N Y(9) N Rheo(7) 1.8V to 5.5V(6) 5 SOT 1
MCP4021(1) U/D NV 63 33.3/79.4/158.7/793.7 Y/Y 1 Y Y N Pot 2.7V to 5.5V 8 SC70 1
MCP4022(1) U/D NV 63 33.3/79.4/158.7/793.7 Y/Y 1 Y Y N Rheo 2.7V to 5.5V 6 SC70 1
MCP4023(1) U/D NV 63 33.3/79.4/158.7/793.7 Y/Y 1 Y Y N Pot(7) 2.7V to 5.5V 6 SC70 1
MCP4024(1) U/D NV 63 33.3/79.4/158.7/793.7 Y/Y 1 Y Y N Rheo(7) 2.7V to 5.5V 5 SC70 1
1. Resistor options are: -202 (2.1 k), -502 (5.0 k), -103 (10.0 k), and -503 (50.0 k).
2. Resistor options are: -502 (5.0 k), -103 (10.0 k), 503 (50.0 k), and -104 (100.0 k).
3. Zero-scale allows the wiper to “directly” connect to Terminal B, while full-scale allows the wiper to “directly” connect to Terminal A.
4. There is one RS resistor between the maximum wiper value and Terminal A.
5. This current is with the serial interface inactive, and not during an EEPROM write cycle (for non-volatile devices).
6. The serial interface has been tested to 1.8V, the device’s analog characteristics (resistor) have been tested from 2.7V to 5.5V. Review the device’s characterization graphs for information on analog performance between
1.8Vand 2.7V.
7. One of the terminal pins (A or B) is internally connected to ground, due to the limitation of the number of pins on the package.
8. Shutdown support via software (TCON register(s)). If device has SHDN pin, software shutdown also fuctions.
9. High voltage command support is for compatibility with the corresponding non-volatile version of the device.
8 Digital Potentiometer Design Guide
SPI Interface
This is also an easy to implement interface, that requires
three or four I/O pins. The additional pins allow data to be
read back from the device or to allow device daisy chaining.
Daisy chaining allows the SPI interface to update all devices
in that chain at the same time.
Many microcontrollers offer this interface as a hardware
module, further simplifying the code development.
High voltage commands require the CS pin forced to the
VIHH voltage, instead of the VIL voltage. In this state, the
WiperLock Technology bit can be enabled and disabled.
Controller to Single Peripheral
Controller to Multiple Peripherals (Multiple Chip Selects)
Digital Potentiometer Solutions
Controller to Single Peripheral with Multiplexed SDI and SDO Pins
Digital Potentiometer Design Guide 9
Digital Potentiometer Solutions
Devices with SPI Interface
Device
Serial
Interface
Volatile (Vol)
Non-Volatile (NV)
# RS Resistors
Rs Ω (typ.)
Zero-Scale/
Full-Scale(3)
# of Channels
WiperLock™
Technology
HV Commands
Shutdown
Mode
Configuration
Voltage
Range
# of Pins
Packages
IDD max (μA)(5)
MCP4131(2) SPI Vol 128 39.1/78.1/390.6/781.3 Y/Y 1 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 8 PDIP, SOIC, MSOP, DFN 5
MCP4132(2) SPI Vol 128 39.1/78.1/390.6/781.3 Y/Y 1 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 8 PDIP, SOIC, MSOP, DFN 5
MCP4141(2) SPI NV 128 39.1/78.1/390.6/781.3 Y/Y 1 Y Y Y(8) Pot 2.7V to 5.5V 8 PDIP, SOIC, MSOP, DFN 5
MCP4142(2) SPI NV 128 39.1/78.1/390.6/781.3 Y/Y 1 Y Y Y(8) Rheo 2.7V to 5.5V 8 PDIP, SOIC, MSOP, DFN 5
MCP4151(2) SPI Vol 256 19.5/39.1/195.3/390.6 Y/Y 1 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 8 PDIP, SOIC, MSOP, DFN 5
MCP4152(2) SPI Vol 256 19.5/39.1/195.3/390.6 Y/Y 1 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 8 PDIP, SOIC, MSOP, DFN 5
MCP4161(2) SPI NV 256 19.5/39.1/195.3/390.6 Y/Y 1 Y Y Y(8) Pot 2.7V to 5.5V 8 PDIP, SOIC, MSOP, DFN 5
MCP4162(2) SPI NV 256 19.5/39.1/195.3/390.6 Y/Y 1 Y Y Y(8) Rheo 2.7V to 5.5V 8 PDIP, SOIC, MSOP, DFN 5
MCP4231(2) SPI Vol 128 39.1/78.1/390.6/781.3 Y/Y 2 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 14, 16 PDIP, SOIC, TSSOP, QFN 5
MCP4232(2) SPI Vol 128 39.1/78.1/390.6/781.3 Y/Y 2 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 10 MSOP, DFN 5
MCP4241(2) SPI NV 128 39.1/78.1/390.6/781.3 Y/Y 2 Y Y Y(8) Pot 2.7V to 5.5V 14, 16 PDIP, SOIC, TSSOP, QFN 5
MCP4242(2) SPI NV 128 39.1/78.1/390.6/781.3 Y/Y 2 Y Y Y(8) Rheo 2.7V to 5.5V 10 MSOP, DFN 5
MCP4251(2) SPI Vol 256 19.5/39.1/195.3/390.6 Y/Y 2 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 14, 16 PDIP, SOIC, TSSOP, QFN 5
MCP4252(2) SPI Vol 256 19.5/39.1/195.3/390.6 Y/Y 2 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 10 MSOP, DFN 5
MCP4261(2) SPI NV 256 19.5/39.1/195.3/390.6 Y/Y 2 Y Y Y(8) Pot 2.7V to 5.5V 14, 16 PDIP, SOIC, TSSOP, QFN 5
MCP4262(2) SPI NV 256 19.5/39.1/195.3/390.6 Y/Y 2 Y Y Y(8) Rheo 2.7V to 5.5V 10 MSOP, DFN 5
MCP4331(2) SPI Vol 128 39.1/78.1/390.6/781.3 Y/Y 4 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 20 TSSOP, QFN 5
MCP4332(2) SPI Vol 128 39.1/78.1/390.6/781.3 Y/Y 4 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 14 TSSOP 5
MCP4341(2) SPI NV 128 39.1/78.1/390.6/781.3 Y/Y 4 Y Y Y(8) Pot 2.7V to 5.5V 20 TSSOP, QFN 5
MCP4342(2) SPI NV 128 39.1/78.1/390.6/781.3 Y/Y 4 Y Y Y(8) Rheo 2.7V to 5.5V 14 TSSOP 5
MCP4351(2) SPI Vol 256 19.5/39.1/195.3/390.6 Y/Y 4 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 20 TSSOP, QFN 5
MCP4352(2) SPI Vol 256 19.5/39.1/195.3/390.6 Y/Y 4 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 14 TSSOP 5
MCP4361(2) SPI NV 256 19.5/39.1/195.3/390.6 Y/Y 4 Y Y Y(8) Pot 2.7V to 5.5V 20 TSSOP, QFN 5
MCP4362(2) SPI NV 256 19.5/39.1/195.3/390.6 Y/Y 4 Y Y Y(8) Rheo 2.7V to 5.5V 14 TSSOP 5
MCP41010 SPI Vol 256 39.1 Y/N(4) 1 N N N Pot 2.7V to 5.5V 8 PDIP, SOIC 1
MCP41050 SPI Vol 256 195.3 Y/N(4) 1 N N N Pot 2.7V to 5.5V 8 PDIP, SOIC 1
MCP41100 SPI Vol 256 390.6 Y/N(4) 1 N N N Pot 2.7V to 5.5V 8 PDIP, SOIC 1
MCP42010 SPI Vol 256 39.1 Y/N(4) 2 N N Y Pot 2.7V to 5.5V 14 PDIP, SOIC, TSSOP 1
MCP42050 SPI Vol 256 195.3 Y/N(4) 2 N N Y Pot 2.7V to 5.5V 14 PDIP, SOIC, TSSOP 1
MCP42100 SPI Vol 256 390.6 Y/N(4) 2 N N Y Pot 2.7V to 5.5V 14 PDIP, SOIC, TSSOP 1
1. Resistor options are: -202 (2.1 k), -502 (5.0 k), -103 (10.0 k), and -503 (50.0 k).
2. Resistor options are: -502 (5.0 k), -103 (10.0 k), 503 (50.0 k), and -104 (100.0 k).
3. Zero-scale allows the wiper to “directly” connect to Terminal B, while full-scale allows the wiper to “directly” connect to Terminal A.
4. There is one RS resistor between the maximum wiper value and Terminal A.
5. This current is with the serial interface inactive, and not during an EEPROM write cycle (for non-volatile devices).
6. The serial interface has been tested to 1.8V, the device’s analog characteristics (resistor) have been tested from 2.7V to 5.5V. Review the device’s characterization graphs for information on analog performance between
1.8Vand 2.7V.
7. One of the terminal pins (A or B) is internally connected to ground, due to the limitation of the number of pins on the package.
8. Shutdown support via software (TCON register(s)). If device has SHDN pin, software shutdown also fuctions.
9. High voltage command support is for compatibility with the corresponding non-volatile version of the device.
10 Digital Potentiometer Design Guide
Digital Potentiometer Solutions
I2C™ Interface
The I2C interface is a two wire interface, where the output
drivers are open drain. This protocol supports reads and
writes using only the interface’s two wires. The I2C protocol
allows multiple devices on the I2C bus, where each device
has a unique device address. The I2C protocol requires more
host controller firmware overhead than the SPI protocol, but
requires less hardware resources (2 pins vs. 3 or 4 pins).
The I2C protocol allows many devices on the I2C bus without
the need to increase the number of I/O pins dedicated by the
master controller. The typical I2C interface is shown. Several
of the Microchip digital potentiometer devices support high
voltage commands. This function requires an additional host
controller output pin.
Many microcontrollers offer this interface as a dedicated
hardware module, which eases the software requirement of
the protocol.
High voltage commands require the HVC/A0 pin forced to
the VIHH voltage, instead of the VIL voltage. In this state, the
WiperLock Technology bit can be enabled and disabled.
Controller to Single Peripheral
Controller to Multiple Peripherals (Multiple Chip Selects)
Digital Potentiometer Design Guide 11
Devices with I2C Interface
Device
Serial
Interface
Volatile (Vol)
Non-Volatile (NV)
# RS Resistors
Rs Ω (typ.)
Zero-Scale/
Full-Scale(3)
# of Channels
WiperLock™
Technology
HV Commands
Shutdown
Mode
Configuration
Voltage
Range
# of Pins
Packages
IDD max (μA)(5)
MCP4017(2) I2C Vol 127 39.4/78.7/393.7/787.4 Y/Y 1 N N N Rheo 1.8V to 5.5V(6) 6 SC70 5
MCP4018(2) I2C Vol 127 39.4/78.7/393.7/787.4 Y/Y 1 N N N Pot(7) 1.8V to 5.5V(6) 6 SC70 5
MCP4019(2) I2C Vol 127 39.4/78.7/393.7/787.4 Y/Y 1 N N N Rheo(7) 1.8V to 5.5V(6) 5 SC70 5
MCP40D17(2) I2C Vol 127 39.4/78.7/393.7/787.4 Y/Y 1 N N N Rheo 1.8V to 5.5V(6) 6 SC70 5
MCP40D18(2) I2C Vol 127 39.4/78.7/393.7/787.4 Y/Y 1 N N N Pot(7) 1.8V to 5.5V(6) 6 SC70 5
MCP40D19(2) I2C Vol 127 39.4/78.7/393.7/787.4 Y/Y 1 N N N Rheo(7) 1.8V to 5.5V(6) 5 SC70 5
MCP4531(2) I2C Vol 128 39.1/78.1/390.6/781.3 Y/Y 1 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 8 MSOP, DFN 5
MCP4532(2) I2C Vol 128 39.1/78.1/390.6/781.3 Y/Y 1 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 8 MSOP, DFN 5
MCP4541(2) I2C NV 128 39.1/78.1/390.6/781.3 Y/Y 1 Y Y Y(8) Pot 2.7V to 5.5V 8 MSOP, DFN 5
MCP4542(2) I2C NV 128 39.1/78.1/390.6/781.3 Y/Y 1 Y Y Y(8) Rheo 2.7V to 5.5V 8 MSOP, DFN 5
MCP4551(2) I2C Vol 256 19.5/39.1/195.3/390.6 Y/Y 1 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 8 MSOP, DFN 5
MCP4552(2) I2C Vol 256 19.5/39.1/195.3/390.6 Y/Y 1 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 8 MSOP, DFN 5
MCP4561(2) I2C NV 256 19.5/39.1/195.3/390.6 Y/Y 1 Y Y Y(8) Pot 2.7V to 5.5V 8 MSOP, DFN 5
MCP4562(2) I2C NV 256 19.5/39.1/195.3/390.6 Y/Y 1 Y Y Y(8) Rheo 2.7V to 5.5V 8 MSOP, DFN 5
MCP4631(2) I2C Vol 128 39.1/78.1/390.6/781.3 Y/Y 2 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 14, 16 TSSOP, QFN 5
MCP4632(2) I2C Vol 128 39.1/78.1/390.6/781.3 Y/Y 2 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 10 MSOP, DFN 5
MCP4641(2) I2C NV 128 39.1/78.1/390.6/781.3 Y/Y 2 Y Y Y(8) Pot 2.7V to 5.5V 14, 16 TSSOP, QFN 5
MCP4642(2) I2C NV 128 39.1/78.1/390.6/781.3 Y/Y 2 Y Y Y(8) Rheo 2.7V to 5.5V 10 MSOP, DFN 5
MCP4651(2) I2C Vol 256 19.5/39.1/195.3/390.6 Y/Y 2 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 14, 16 TSSOP, QFN 5
MCP4652(2) I2C Vol 256 19.5/39.1/195.3/390.6 Y/Y 2 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 10 MSOP, DFN 5
MCP4661(2) I2C NV 256 19.5/39.1/195.3/390.6 Y/Y 2 Y Y Y(8) Pot 2.7V to 5.5V 14, 16 TSSOP, QFN 5
MCP4662(2) I2C NV 256 19.5/39.1/195.3/390.6 Y/Y 2 Y Y Y(8) Rheo 2.7V to 5.5V 10 MSOP, DFN 5
MCP4431(2) I2C Vol 128 39.1/78.1/390.6/781.3 Y/Y 4 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 20 TSSOP, QFN 5
MCP4432(2) I2C Vol 128 39.1/78.1/390.6/781.3 Y/Y 4 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 14 TSSOP 5
MCP4441(2) I2C NV 128 39.1/78.1/390.6/781.3 Y/Y 4 Y Y Y(8) Pot 2.7V to 5.5V 20 TSSOP, QFN 5
MCP4442(2) I2C NV 128 39.1/78.1/390.6/781.3 Y/Y 4 Y Y Y(8) Rheo 2.7V to 5.5V 14 TSSOP 5
MCP4451(2) I2C Vol 256 19.5/39.1/195.3/390.6 Y/Y 4 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 20 TSSOP, QFN 5
MCP4452(2) I2C Vol 256 19.5/39.1/195.3/390.6 Y/Y 4 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 14 TSSOP 5
MCP4461(2) I2C NV 256 19.5/39.1/195.3/390.6 Y/Y 4 Y Y Y(8) Pot 2.7V to 5.5V 20 TSSOP, QFN 5
MCP4462(2) I2C NV 256 19.5/39.1/195.3/390.6 Y/Y 4 Y Y Y(8) Rheo 2.7V to 5.5V 14 TSSOP 5
1. Resistor options are: -202 (2.1 k), -502 (5.0 k), -103 (10.0 k), and -503 (50.0 k).
2. Resistor options are: -502 (5.0 k), -103 (10.0 k), 503 (50.0 k), and -104 (100.0 k).
3. Zero-scale allows the wiper to “directly” connect to Terminal B, while full-scale allows the wiper to “directly” connect to Terminal A.
4. There is one RS resistor between the maximum wiper value and Terminal A.
5. This current is with the serial interface inactive, and not during an EEPROM write cycle (for non-volatile devices).
6. The serial interface has been tested to 1.8V, the device’s analog characteristics (resistor) have been tested from 2.7V to 5.5V. Review the device’s characterization graphs for information on analog performance between
1.8Vand 2.7V.
7. One of the terminal pins (A or B) is internally connected to ground, due to the limitation of the number of pins on the package.
8. Shutdown support via software (TCON register(s)). If device has SHDN pin, software shutdown also fuctions.
9. High voltage command support is for compatibility with the corresponding non-volatile version of the device.
Digital Potentiometer Solutions
12 Digital Potentiometer Design Guide
Single, Dual and Quad Potentiometer Options
Some devices offer multiple resistor networks on the same
device. Currently up to 4 resistor networks are available
on a single device. These resistor networks are referred to
as Pot 0 (Potentiometer 0), Pot 1, Pot 2 and Pot 3. Having
multiple potentiometers on the same device offers several
advantages, including:
■ Cost per potentiometer
■ PCB layout area per potentiometer
■ Variation between potentiometers
Digital Potentiometer Solutions
In some applications, the RAB resistance variation between
potentiometer is important for the application circuit. When
these potentiometers are on the same silicon, the RAB
resistance is small compared to the possible variation of
the RAB resistance on different devices. The data sheets for
devices with multiple resistor networks have RAB matching
specifications as well as additional information in the
characterization graph section.
The quad potentiometer devices are defined so that the
for the same leaded package type (such as TSSOP) the
Quad and Dual devices have a compatible footprint. The
following figure shows footprint compatibility for both the
MCP4261 MCP4361 and the MCP4262 MCP4362.
Quad Pinout vs. Dual Pinout (TSSOP Package)
Digital Potentiometer Design Guide 13
Digital Potentiometer Solutions
Single Potentiometer Devices
Device
Serial
Interface
Volatile (Vol)
Non-Volatile (NV)
# RS Resistors
Rs Ω (typ.)
Zero-Scale/
Full-Scale(3)
# of Channels
WiperLock™
Technology
HV Commands
Shutdown
Mode
Configuration
Voltage
Range
# of Pins
Packages
IDD max (μA)(5)
MCP4011(1) U/D Vol 63 33.3/79.4/158.7/793.7 Y/Y 1 N Y(9) N Pot 1.8V to 5.5V(6) 8 DFN 2x3 1
MCP4012(1) U/D Vol 63 33.3/79.4/158.7/793.7 Y/Y 1 N Y(9) N Rheo 1.8V to 5.5V(6) 6 SOT 1
MCP4013(1) U/D Vol 63 33.3/79.4/158.7/793.7 Y/Y 1 N Y(9) N Pot(7) 1.8V to 5.5V(6) 6 SOT 1
MCP4014(1) U/D Vol 63 33.3/79.4/158.7/793.7 Y/Y 1 N Y(9) N Rheo(7) 1.8V to 5.5V(6) 5 SOT 1
MCP4021(1) U/D NV 63 33.3/79.4/158.7/793.7 Y/Y 1 Y Y N Pot 2.7V to 5.5V 8 SC70 1
MCP4022(1) U/D NV 63 33.3/79.4/158.7/793.7 Y/Y 1 Y Y N Rheo 2.7V to 5.5V 6 SC70 1
MCP4023(1) U/D NV 63 33.3/79.4/158.7/793.7 Y/Y 1 Y Y N Pot(7) 2.7V to 5.5V 6 SC70 1
MCP4024(1) U/D NV 63 33.3/79.4/158.7/793.7 Y/Y 1 Y Y N Rheo(7) 2.7V to 5.5V 5 SC70 1
MCP4017(2) I2C Vol 127 39.4/78.7/393.7/787.4 Y/Y 1 N N N Rheo 1.8V to 5.5V(6) 6 SC70 5
MCP4018(2) I2C Vol 127 39.4/78.7/393.7/787.4 Y/Y 1 N N N Pot(7) 1.8V to 5.5V(6) 6 SC70 5
MCP4019(2) I2C Vol 127 39.4/78.7/393.7/787.4 Y/Y 1 N N N Rheo(7) 1.8V to 5.5V(6) 5 SC70 5
MCP40D17(2) I2C Vol 127 39.4/78.7/393.7/787.4 Y/Y 1 N N N Rheo 1.8V to 5.5V(6) 6 SC70 5
MCP40D18(2) I2C Vol 127 39.4/78.7/393.7/787.4 Y/Y 1 N N N Pot(7) 1.8V to 5.5V(6) 6 SC70 5
MCP40D19(2) I2C Vol 127 39.4/78.7/393.7/787.4 Y/Y 1 N N N Rheo(7) 1.8V to 5.5V(6) 5 SC70 5
MCP4531(2) I2C Vol 128 39.1/78.1/390.6/781.3 Y/Y 1 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 8 MSOP, DFN 5
MCP4532(2) I2C Vol 128 39.1/78.1/390.6/781.3 Y/Y 1 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 8 MSOP, DFN 5
MCP4541(2) I2C NV 128 39.1/78.1/390.6/781.3 Y/Y 1 Y Y Y(8) Pot 2.7V to 5.5V 8 MSOP, DFN 5
MCP4542(2) I2C NV 128 39.1/78.1/390.6/781.3 Y/Y 1 Y Y Y(8) Rheo 2.7V to 5.5V 8 MSOP, DFN 5
MCP4551(2) I2C Vol 256 19.5/39.1/195.3/390.6 Y/Y 1 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 8 MSOP, DFN 5
MCP4552(2) I2C Vol 256 19.5/39.1/195.3/390.6 Y/Y 1 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 8 MSOP, DFN 5
MCP4561(2) I2C NV 256 19.5/39.1/195.3/390.6 Y/Y 1 Y Y Y(8) Pot 2.7V to 5.5V 8 MSOP, DFN 5
MCP4562(2) I2C NV 256 19.5/39.1/195.3/390.6 Y/Y 1 Y Y Y(8) Rheo 2.7V to 5.5V 8 MSOP, DFN 5
MCP4531(2) I2C Vol 128 39.1/78.1/390.6/781.3 Y/Y 1 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 8 MSOP, DFN 5
MCP4532(2) I2C Vol 128 39.1/78.1/390.6/781.3 Y/Y 1 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 8 MSOP, DFN 5
MCP4541(2) I2C NV 128 39.1/78.1/390.6/781.3 Y/Y 1 Y Y Y(8) Pot 2.7V to 5.5V 8 MSOP, DFN 5
MCP4542(2) I2C NV 128 39.1/78.1/390.6/781.3 Y/Y 1 Y Y Y(8) Rheo 2.7V to 5.5V 8 MSOP, DFN 5
MCP4551(2) I2C Vol 256 19.5/39.1/195.3/390.6 Y/Y 1 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 8 MSOP, DFN 5
MCP4552(2) I2C Vol 256 19.5/39.1/195.3/390.6 Y/Y 1 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 8 MSOP, DFN 5
MCP4561(2) I2C NV 256 19.5/39.1/195.3/390.6 Y/Y 1 Y Y Y(8) Pot 2.7V to 5.5V 8 MSOP, DFN 5
MCP4562(2) I2C NV 256 19.5/39.1/195.3/390.6 Y/Y 1 Y Y Y(8) Rheo 2.7V to 5.5V 8 MSOP, DFN 5
MCP41010 SPI Vol 256 39.1 Y/N(4) 1 N N N Pot 2.7V to 5.5V 8 PDIP, SOIC 1
MCP41050 SPI Vol 256 195.3 Y/N(4) 1 N N N Pot 2.7V to 5.5V 8 PDIP, SOIC 1
MCP41100 SPI Vol 256 390.6 Y/N(4) 1 N N N Pot 2.7V to 5.5V 8 PDIP, SOIC 1
1. Resistor options are: -202 (2.1 k), -502 (5.0 k), -103 (10.0 k), and -503 (50.0 k).
2. Resistor options are: -502 (5.0 k), -103 (10.0 k), 503 (50.0 k), and -104 (100.0 k).
3. Zero-scale allows the wiper to “directly” connect to Terminal B, while full-scale allows the wiper to “directly” connect to Terminal A.
4. There is one RS resistor between the maximum wiper value and Terminal A.
5. This current is with the serial interface inactive, and not during an EEPROM write cycle (for non-volatile devices).
6. The serial interface has been tested to 1.8V, the device’s analog characteristics (resistor) have been tested from 2.7V to 5.5V. Review the device’s characterization graphs for information on analog performance between
1.8Vand 2.7V.
7. One of the terminal pins (A or B) is internally connected to ground, due to the limitation of the number of pins on the package.
8. Shutdown support via software (TCON register(s)). If device has SHDN pin, software shutdown also fuctions.
9. High voltage command support is for compatibility with the corresponding non-volatile version of the device.
14 Digital Potentiometer Design Guide
Dual Potentiometer Devices
Device
Serial
Interface
Volatile (Vol)
Non-Volatile (NV)
# RS Resistors
Rs Ω (typ.)
Zero-Scale/
Full-Scale(3)
# of Channels
WiperLock™
Technology
HV Commands
Shutdown
Mode
Configuration
Voltage
Range
# of Pins
Packages
IDD max (μA)(5)
MCP4231(2) SPI Vol 128 39.1/78.1/390.6/781.3 Y/Y 2 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 14, 16 PDIP, SOIC, TSSOP, QFN 5
MCP4232(2) SPI Vol 128 39.1/78.1/390.6/781.3 Y/Y 2 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 10 MSOP, DFN 5
MCP4241(2) SPI NV 128 39.1/78.1/390.6/781.3 Y/Y 2 Y Y Y(8) Pot 2.7V to 5.5V 14, 16 PDIP, SOIC, TSSOP, QFN 5
MCP4242(2) SPI NV 128 39.1/78.1/390.6/781.3 Y/Y 2 Y Y Y(8) Rheo 2.7V to 5.5V 10 MSOP, DFN 5
MCP4251(2) SPI Vol 256 19.5/39.1/195.3/390.6 Y/Y 2 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 14, 16 PDIP, SOIC, TSSOP, QFN 5
MCP4252(2) SPI Vol 256 19.5/39.1/195.3/390.6 Y/Y 2 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 10 MSOP, DFN 5
MCP4261(2) SPI NV 256 19.5/39.1/195.3/390.6 Y/Y 2 Y Y Y(8) Pot 2.7V to 5.5V 14, 16 PDIP, SOIC, TSSOP, QFN 5
MCP4262(2) SPI NV 256 19.5/39.1/195.3/390.6 Y/Y 2 Y Y Y(8) Rheo 2.7V to 5.5V 10 MSOP, DFN 5
MCP4631(2) I2C Vol 128 39.1/78.1/390.6/781.3 Y/Y 2 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 14, 16 TSSOP, QFN 5
MCP4632(2) I2C Vol 128 39.1/78.1/390.6/781.3 Y/Y 2 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 10 MSOP, DFN 5
MCP4641(2) I2C NV 128 39.1/78.1/390.6/781.3 Y/Y 2 Y Y Y(8) Pot 2.7V to 5.5V 14, 16 TSSOP, QFN 5
MCP4642(2) I2C NV 128 39.1/78.1/390.6/781.3 Y/Y 2 Y Y Y(8) Rheo 2.7V to 5.5V 10 MSOP, DFN 5
MCP4651(2) I2C Vol 256 19.5/39.1/195.3/390.6 Y/Y 2 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 14, 16 TSSOP, QFN 5
MCP4652(2) I2C Vol 256 19.5/39.1/195.3/390.6 Y/Y 2 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 10 MSOP, DFN 5
MCP4661(2) I2C NV 256 19.5/39.1/195.3/390.6 Y/Y 2 Y Y Y(8) Pot 2.7V to 5.5V 14, 16 TSSOP, QFN 5
MCP4662(2) I2C NV 256 19.5/39.1/195.3/390.6 Y/Y 2 Y Y Y(8) Rheo 2.7V to 5.5V 10 MSOP, DFN 5
MCP42010 SPI Vol 256 39.1 Y/N(4) 2 N N Y Pot 2.7V to 5.5V 14 PDIP, SOIC, TSSOP 1
MCP42050 SPI Vol 256 195.3 Y/N(4) 2 N N Y Pot 2.7V to 5.5V 14 PDIP, SOIC, TSSOP 1
MCP42100 SPI Vol 256 390.6 Y/N(4) 2 N N Y Pot 2.7V to 5.5V 14 PDIP, SOIC, TSSOP 1
1. Resistor options are: -202 (2.1 k), -502 (5.0 k), -103 (10.0 k), and -503 (50.0 k).
2. Resistor options are: -502 (5.0 k), -103 (10.0 k), 503 (50.0 k), and -104 (100.0 k).
3. Zero-scale allows the wiper to “directly” connect to Terminal B, while full-scale allows the wiper to “directly” connect to Terminal A.
4. There is one RS resistor between the maximum wiper value and Terminal A.
5. This current is with the serial interface inactive, and not during an EEPROM write cycle (for non-volatile devices).
6. The serial interface has been tested to 1.8V, the device’s analog characteristics (resistor) have been tested from 2.7V to 5.5V. Review the device’s characterization graphs for information on analog performance between
1.8Vand 2.7V.
7. One of the terminal pins (A or B) is internally connected to ground, due to the limitation of the number of pins on the package.
8. Shutdown support via software (TCON register(s)). If device has SHDN pin, software shutdown also fuctions.
9. High voltage command support is for compatibility with the corresponding non-volatile version of the device.
Digital Potentiometer Solutions
Digital Potentiometer Design Guide 15
Quad Potentiometer Devices
Device
Serial
Interface
Volatile (Vol)
Non-Volatile (NV)
# RS Resistors
Rs Ω (typ.)
Zero-Scale/
Full-Scale(3)
# of Channels
WiperLock™
Technology
HV Commands
Shutdown
Mode
Configuration
Voltage
Range
# of Pins
Packages
IDD max (μA)(5)
MCP4331(2) SPI Vol 128 39.1/78.1/390.6/781.3 Y/Y 4 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 20 TSSOP, QFN 5
MCP4332(2) SPI Vol 128 39.1/78.1/390.6/781.3 Y/Y 4 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 14 TSSOP 5
MCP4341(2) SPI NV 128 39.1/78.1/390.6/781.3 Y/Y 4 Y Y Y(8) Pot 2.7V to 5.5V 20 TSSOP, QFN 5
MCP4342(2) SPI NV 128 39.1/78.1/390.6/781.3 Y/Y 4 Y Y Y(8) Rheo 2.7V to 5.5V 14 TSSOP 5
MCP4351(2) SPI Vol 256 19.5/39.1/195.3/390.6 Y/Y 4 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 20 TSSOP, QFN 5
MCP4352(2) SPI Vol 256 19.5/39.1/195.3/390.6 Y/Y 4 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 14 TSSOP 5
MCP4361(2) SPI NV 256 19.5/39.1/195.3/390.6 Y/Y 4 Y Y Y(8) Pot 2.7V to 5.5V 20 TSSOP, QFN 5
MCP4362(2) SPI NV 256 19.5/39.1/195.3/390.6 Y/Y 4 Y Y Y(8) Rheo 2.7V to 5.5V 14 TSSOP 5
MCP4431(2) I2C Vol 128 39.1/78.1/390.6/781.3 Y/Y 4 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 20 TSSOP, QFN 5
MCP4432(2) I2C Vol 128 39.1/78.1/390.6/781.3 Y/Y 4 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 14 TSSOP 5
MCP4441(2) I2C NV 128 39.1/78.1/390.6/781.3 Y/Y 4 Y Y Y(8) Pot 2.7V to 5.5V 20 TSSOP, QFN 5
MCP4442(2) I2C NV 128 39.1/78.1/390.6/781.3 Y/Y 4 Y Y Y(8) Rheo 2.7V to 5.5V 14 TSSOP 5
MCP4451(2) I2C Vol 256 19.5/39.1/195.3/390.6 Y/Y 4 N Y(9) Y(8) Pot 1.8V to 5.5V(6) 20 TSSOP, QFN 5
MCP4452(2) I2C Vol 256 19.5/39.1/195.3/390.6 Y/Y 4 N Y(9) Y(8) Rheo 1.8V to 5.5V(6) 14 TSSOP 5
MCP4461(2) I2C NV 256 19.5/39.1/195.3/390.6 Y/Y 4 Y Y Y(8) Pot 2.7V to 5.5V 20 TSSOP, QFN 5
MCP4462(2) I2C NV 256 19.5/39.1/195.3/390.6 Y/Y 4 Y Y Y(8) Rheo 2.7V to 5.5V 14 TSSOP 5
1. Resistor options are: -202 (2.1 k), -502 (5.0 k), -103 (10.0 k), and -503 (50.0 k).
2. Resistor options are: -502 (5.0 k), -103 (10.0 k), 503 (50.0 k), and -104 (100.0 k).
3. Zero-scale allows the wiper to “directly” connect to Terminal B, while full-scale allows the wiper to “directly” connect to Terminal A.
4. There is one RS resistor between the maximum wiper value and Terminal A.
5. This current is with the serial interface inactive, and not during an EEPROM write cycle (for non-volatile devices).
6. The serial interface has been tested to 1.8V, the device’s analog characteristics (resistor) have been tested from 2.7V to 5.5V. Review the device’s characterization graphs for information on analog performance between
1.8Vand 2.7V.
7. One of the terminal pins (A or B) is internally connected to ground, due to the limitation of the number of pins on the package.
8. Shutdown support via software (TCON register(s)). If device has SHDN pin, software shutdown also fuctions.
9. High voltage command support is for compatibility with the corresponding non-volatile version of the device.
Digital Potentiometer Solutions
16 Digital Potentiometer Design Guide
Digital Potentiometer Solutions
Voltage Windowing
Resistance Options and Resolutions
Microchip offers Digital Potentiometer devices with typical
RAB resistances of 2.1 K, 5 K, 10 K, 50 K and 100
K. The devices offer either 6-, 7- or 8-bits of resolution.
The step resistance (RS) is the RAB resistances divided by
the number of RS resistors in the RAB ladder.
The step resistance is important to understand when
you are using the device in a rheostat mode, or the
potentiometer is being windowed by resistors on the
Terminal A and/or on the Terminal B.
Voltage Windowing
Terminal A and Terminal B may for example be any
voltage within the device specification limits. Lets call the
voltages at these nodes VA and VB. So the voltage across
the resistor RAB (VAB) is | VA - VB |. The VAB voltage is
determined by the values of the R1, R2 and RAB resistors.
As the VAB voltage becomes smaller relative to the voltage
range, the effective resolution of the device increase,
though the resolution is limited to between the VA and VB
voltages.
This allows a less precise device to be used for more
precise circuit tuning over a narrower range. When
replacing a mechanical potentiometer, this configuration
can be used and R1 and R2 may be any resistance
(including 0).
Resistance Options
RAB 6-bit (63) 7-bit (127) 7-bit (128) 8-bit (256)
2100 33.33333333 – – –
5000 79.36507937 39.37007874 39.0625 19.53125
10000 158.7301587 78.74015748 78.125 39.0625
50000 793.6507937 393.7007874 390.625 195.3125
100000 – 787.4015748 781.25 390.625
How the VAB Voltage Effects the Effective Resolution
VAB
mV per Step Effective VAB Resolution vs. Fixed VDD
Comment
6-bit (63) 7-bit (127) 7-bit (128) 8-bit (256) 6-bit (63) 7-bit (127) 7-bit (128) 8-bit (256)
5.00 79.4E 39.4E 39.1E 19.5E 6-bit 7-bit 7-bit 8-bit VAB = VDD
2.50 39.7E 19.7E 19.5E 9.8E 7-bit 8-bit 8-bit 9-bit VDD = 5.0V
1.25 19.8E 9.8E 9.8E 4.9E 8-bit 9-bit 9-bit 10-bit VDD = 5.0V
Digital Potentiometer Design Guide 17
Application Circuits and Techniques
Digital potentiometers are a good fit for applications to trim
offset and gain in amplifier circuits. In this following circuit,
a resistor ladder is used to create a voltage window where
Pot1 is used to trim the desired offset for the inverting
amplifier. A second potentiometer (Pot2) is used in a
rheostat mode along with resistor R3 to control the gain of
the amplifier. The step resistance of Pot2 relative to resistor
R3 determines if the gain trimming is a fine adjustment or a
course adjustment. Capacitor C1 is for compensation of the
op amp and to inhibit the output from oscillating.
In this circuit, there is no interaction between the offset
trimming and the gain trimming, but the input signal (VIN) is
loaded by the resistance of R3 plus Pot2’s RBW value.
In the following circuit, a resistor ladder is used to create
a voltage window where Pot1 is used to trim the desired
offset for the non-inverting amplifier. A second potentiometer
is used in a rheostat mode to control the gain of the
amplifier. The step resistance of Pot2 relative to resistor R3
determines if the gain trimming is a fine adjustment or a
course adjustment. Capacitor C1 is for compensation of the
op amp and to inhibit the output from oscillating.
In this circuit, there is an interaction between the offset
trimming and the gain trimming. To minimize this interaction,
Pot2 should be small compared to resistor R3 and Pot1
should be small relative to the sum of R1 and R2. But the
input signal (VIN) is not loaded.
Additional information can be found in application note AN1316.
Inverting Amplifier with Offset and Gain Trimming
Non-Inverting Amplifier with Offset and Gain Trimming
Digital Potentiometer Solutions
In the following circuit, a resistor ladder is used to create a
voltage window where Pot1 is used to trim the desired offset
for the band pass filter. This resistor ladder setting also
works with capacitor C2 to set the high pass filter frequency.
A second potentiometer (Pot2) is used in a rheostat mode
along with R3 and R4 to control the gain of the amplifier.
The step resistance of Pot2 relative to resistors R3 and R4
determines if the gain trimming is a fine adjustment or a
course adjustment. Capacitor C1 along with Pot2, R3 and R4
is used to set the low pass filter.
Capacitor C1 is also used for compensation of the Op Amp
and to inhibit the output from oscillating.
If capacitor C1 is not present, then the circuit is a high pass
filter, while if capacitor C2 is not present then the circuit is a
low pass filter.
The following circuit will the use of an RC filter (Potx and
Cx) will filter at the selected frequency. that frequency is
determined by the rheostat value (RBW) of the Pot and the
capacitor value (Cx). each additional stage of the RC filter is
used to enhance the roll-off characteristics for the filter. The
capacitors Cx should be the same, while the wiper values
of the Pots should be similar. The differences would be to
compensate for the slight variations of the RAB values of
each Pot and the variations of the capacitors.
Band Pass Filter with Offset and Gain Trimming
Programmable Filter
18 Digital Potentiometer Design Guide
The following circuit shows a Wheatstone Bridge with current
limiting. In a Wheatstone Bridge, there are four resistive
elements. In this example, two are fixed value (R1 and R2),
there is a resistive sensor (RSENSOR) and then there is the
digital potentiometer in rheostat configuration to calibrate the
circuit due to variations of the resistive sensor. This sensor
could be for temperature or weight measurement.
At a default condition the sensor should be a given value, but
this value will change from device to device. To compensate
for the resistive changes in the R1 plus RSENSOR leg of the
bridge, the Rheo2 would be modified for the R2 plus Rheo2
leg of the bridge. This would be done so that the voltages of
VBRG1 and VBRG2 are at their desired levels. Many times this
is VBRG1 = VBRG2.
Now as the conditions on the sensor change, the resistance
of the sensor will change, causing the VBRG2 voltage to
change. The delta voltage between VBRG1 and VBRG2 can then
be used to determine the state of the system (temperature,
weight, etc.).
Rheo 1 is used in a rheostat mode to limit the current or trim
the current through the Wheatstone Bridge.
Implementing a More Precise Rheostat
The RAB value of a typical digital potentiometer can vary as
much as ±20%, so a device with a 10 k RAB value could
have an RAB value as small as 8 k, as large as 12 k. In
a system, this variation for the rheostat value may not be
desirable. This variation can be calibrated out to make a
precise rheostat, at a cost of the resolution of the device.
If we design the application circuit where this rheostat
only operates from 0 to 8 k, all digital potentiometer
devices (over process) will meet this requirement. Now with
calibration, we will need to ensure that the wiper value is
limited to a value where the rheostat value is the closest
resistance value to the desired rheostat target value of 8
k. The worst case (lowest) wiper value occurs when the RAB
value is 12 k. In this case, a wiper value of 171. results
in a resistance of 8016. This results in a resolution of
approximately 7.4 bits, or 0.58%.
In potentiometer mode, the process variation of the RAB value
may not be an application issue since the device is operating
as a voltage divider.
Logarithmic Steps
Logarithmic steps are desirable since the human ear hears
in a logarithmic manner. The use of a linear potentiometer
can approximate a log potentiometer, but with fewer steps.
An 8-bit potentiometer can achieve fourteen 3 dB log steps
plus a 100% (0 dB) and a mute setting.
The figure below shows a block diagram of one of the
MCP44X1 resistor networks being used to attenuate an
input signal. In this case, the attenuation will be ground
referenced. Terminal B can be connected to a common mode
voltage, but the voltages on the A, B and Wiper terminals
must not exceed the MCP44X1 device’s VDD/VSS voltage
limits.
The following equation shows how to calculate voltage dB
gain ratios for the digital potentiometer.
More detail on this can be found in Section 8.5 of the
MCP444X/446X Data Sheet (DS22265).
Wheatstone Bridge Trimming
Digital Potentiometer Solutions
Signal Attenuation Block Diagram - Ground Referenced
dB Calculations (Voltage)
Digital Potentiometer Design Guide 19
MCP402X Non-Volatile Digital Potentiometer
Evaluation Board (MCP402XEV)
This low-cost board enables user’s to
exercise all of the features of the MCP401X
and MCP402X devices. Kit includes one
populated and one unpopulated PCB. The
populated board has an MCP4021-103E/
SN digital potentiometer configured as a “windowed”
potentiometer using a 2.5 kΩ pull-up and a 2.5kΩ pull-down
resistor. The PCB supports the 8-pin SOIC, SOT-23-6 and
SOT-23-5 package variations. The unpopulated PCB allows
user’s to build the exact combination of components their
application requires.
MCP42X1 Evaluation Board (MCP42X1EV)
The MCP42XXEV Evaluation Board allows
the system designer to quickly evaluate the
operation of Microchip Technology’s MCP4261
Digital Potentiometer device. The board uses the
TSSOP20EV Generic PCB and has been populated
for the MCP4261. The 6-pin header (PICkit Serial)
has been jumpered to the appropriate pins on the
MCP4261 device, allowing the PICkit Serial to communicate
with the device.
MCP43X1 Evaluation Board (MCP43X1EV)
The MCP43XXEV Evaluation Board allows
the system designer to quickly evaluate the
operation of Microchip Technology’s MCP4361
Digital Potentiometer device. The board uses the
TSSOP20EV Generic PCB and has been populated
for the MCP4361. The 6-pin header (PICkit Serial)
has been jumpered to the appropriate pins on the
MCP4361 device, allowing the PICkit Serial to communicate
with the device.
MCP46X1 Evaluation Board (MCP46X1EV)
The MCP46XXEV Evaluation Board allows
the system designer to quickly evaluate the
operation of Microchip Technology’s MCP4661
Digital Potentiometer device. The board uses the
TSSOP20EV Generic PCB and has been populated
for the MCP4661. The 6-pin header (PICkit Serial)
has been jumpered to the appropriate pins on the
MCP4661 device, allowing the PICkit Serial to communicate
with the device.
MCP4XXX Digital Potentiometer Daughter Board
(MCP4XXXDM-DB)
This board allows evaluation of the
MCP42XXX and MCP402X Digital
Potentiometers. The MCP42XXX are dual
digital potentiometer devices that have the
same characteristics as the single digital
potentiometer devices (MCP41XXX). The MCP402X devices
are non-volatile and have similar characteristics to their
volatile memory versions (MCP401X). The board supports
two MCP42XXX devices to allow the resistor networks to
be “stacked” and form a programmable windowed digital
potentiometer. The board also has a voltage doubler device
(TC1240A), which can be used to show the WiperLock
Technology feature of the MCP4021.
Demo/Evaluation Support
Microchip Technology offers several boards that support the
demonstration and evaluation of the digital potentiometer
devices. These boards fall into two categories:
■ Populated boards to demonstrate/evaluate the specific
device(s)
■ Blank printed circuit boards (PCBs)
The blank PCBs allow customers to populate the device and
supporting circuit to best evaluate the performance and
characteristics of the desired device configuration.
The following boards are available on the Microchip web site
at: www.microchip.com/analogtools.
Name Part
Number
Package Supported
# Pins Device/Pkg Type
MCP401X Evaluation
Board
MCP401XEV – MCP401X
MCP402X Non-Volatile
Digital Potentiometer
Evaluation Board
MCP402XEV – MCP40X1 (SOT-23)
MCP42X1 Evaluation
Board
MCP42X1EV – MCP42X1
MCP43X1 Evaluation
Board
MCP43X1EV – MCP43X1
MCP46X1 Evaluation
Board
MCP46X1EV – MCP46X1
MCP4XXX Digital
Potentiometer
Daughter Board
MCP4XXXDM-DB – MCP42XXX (DIP) and
MCP40X1 (SOIC)
MCP42XX PICtail™
Plus Daughter Board
MCP42XXDM-PTPLS – MCP42XX
MCP46XX PICtail Plus
Daughter Board
MCP46XXDM-PTPLS – MCP46XX
SOT-23-5/6 Voltage
Supervisor Evaluation
Board
VSUPEV2 5 & 6 SOT-23
8-pin SOIC/MSOP/
TSSOP/DIP Evaluation
Board
SOIC8EV 8 DIP, MSOP, SOIC and
TSSOP
14-pin SOIC/TSSOP/
DIP Evaluation Board
SOIC14EV 14 DIP, SOIC and TSSOP
20-pin TSSOP/SSOP
Evaluation Board
TSSOP20EV 20 TSSOP and SSOP
MCP401X Evaluation Board (MCP401XEV)
The MCP401XEV Evaluation Board allows
the system designer to quickly evaluate the
operation of Microchip Technology’s MCP40D18
Digital Potentiometer device. The board uses
the SC70EV Generic PCB and has been
populated for the MCP40D18. The 6-pin header (PICkit
Serial) has been jumpered
to the appropriate pins on the
MCP40D18 device, allowing the PICkit Serial to communicate
with the device.
The User’s Guide includes demonstrations of
the PICkit Serial controlling the MCP40D18 device.
Digital Potentiometer Solutions
20 Digital Potentiometer Design Guide
The following literature is available on the Microchip web
site: www.microchip.com/appnotes. There are additional
application notes that may be useful.
AN219: Comparing Digital Potentiometers to Mechanical
Potentiometers
This application note compares two types of potentiometers
– the mechanical poten tiometer (also called a trimmer
potentiometer) and the digital potentiometer. Resistor
potentiometers can be found in electronic cir cuits across a
wide spectrum of applications. Most typ ically, they function
in a voltage divider confi guration in order to execute various
types of tasks, such as offset or gain adjust.
AN691: Optimizing Digital Potentiometer Circuits to
Reduce Absolute Temperature Variations
Circuit ideas are presented that use the necessary design
techniques to mitigate errors, consequently optimizing the
performance of the digital potentiometer.
AN692: Using Digital Potentiometers to Optimize a
Precision Single-Supply Photo Detect Circuit
This application note shows how the adjustability of the
digital potentiometer can be used to an advantage in
photosensing circuits.
AN737: Using Digital Potentiometers to Design
Low-Pass Adjustable Filters
A programmable, second-order, low-pass fi lter is presented
in four different scenarios. The fi rst three scenarios will
illustrate how a dual digital potentiometer and a single
amplifi er can be confi gured for low-pass second-order
Butterworth, Bessel and Chebyshev responses with a
programma ble corner frequency range of 1:100. An example
of the digital potentiometer setting for these designs is
summarized. The fourth scenario will show the same circuit
design, where all three approximation methods (Butterworth,
Bessel and Chebyshev) can coexist with a programmable
corner frequency range of 1:10.
AN746: Interfacing Microchip’s MCP41XXX/MCP4XXX
Digital Potentiometer to a PIC® Microcontroller
Communications between the MCP41XXX and MCP42XXX
family of digital potentiometers and a PIC16F876
microcontroller is discussed. These devices communicate
using a standard 3-wire SPI compatible interface. The code
supplied with this application note will include both absolute
and relocatable assembly code, written for both hardware SPI
and fi rmware SPI implementations.
Digital Potentiometer Solutions
MCP42XX PICtail Plus Daughter Board
(MCP42XXDM-PTPLS)
This daughter board is used to
demonstrate the operation of Microchip’s
MCP42XX or MCP41XX digital
potentiometers. This board is designed
to be used in conjunction with either the PIC24 Explorer 16
Demo Board or the PICkit™ Serial Analyzer.
MCP46XX PICtail Plus Daughter Board
(MCP46XXDM-PTPLS)
This daughter board demonstrates the
features and abilities of Microchip’s
MCP45XX and MCP46XX Digital
Potentiometers. This board is designed to
exclusively use the MCP46X1 devices. The MCP4661 uses
an I2C interface and can be controlled via the PICkit Serial
Analyzer interface or via the PICtail Plus interface.
SOT-23-5/6 Voltage Supervisor Evaluation Board
(VSUPEV2)
This blank PCB allows quick evaluation of
voltage supervisors and voltage detectors
in the SOT-23-5 and SOT-23-6 packages.
This PCB supports many Microchip
devices, including the non-volatile Digital
Potentiometer and PIC10F2XX devices.
SOIC 8-lead Evaluation Board (SOIC8EV)
A blank PCB to easily evaluate Microchip’s
8-pin devices (in SOIC, DIP, MSOP and
TSSOP packages). Each device pin is
connected to a pull-up resistor, a pull-down
resistor, an in-line resistor and a loading
capacitor. The PCB pads allow through hole or surface mount
connectors to be installed to ease connection to the board.
Additional passive component footprints are on the board, to
allow simple circuits to be implemented.
14-pin SOIC/TSSOP/DIP Evaluation Board (SOIC14EV)
This 14-lead SOIC/TSSOP/DIP evaluation board
allows system designers to quickly evaluate the
operation of Microchip devices in either SOIC, DIP
or TSSOP packages.
20-pin TSSOP/SSOP Evaluation Board (TSSOP20EV)
This 20-pin TSSOP and SSOP evaluation board
allows system designers to quickly evaluate
the operation of Microchip devices in any of the
following 20-pin packages: TSSOP-20/16/14/8
or SSOP-20. The board has a 6-pin header (PICkit
Serial, ICSP™ , etc.) that can be easily jumpered
to the device’s desired pins to communicate
with the device (using PICkit Serial) or in the case of PIC
microcontrollers or EEPROM, programmed (using ICSP).
Digital Potentiometer Design Guide 21
Stand-Alone Analog and Interface Products
Digital Potentiometer Solutions
AN747: Communicating with Daisy Chained MCP42XXX
Digital Potentiometers
The MCP41XXX and MCP42XXX family of digital
potentiometers allow for daisy chaining of multiple devices
on a single SPI bus. It is possible to communicate to multiple
devices using one 3-wire data bus (CS, CLK and DATA), by
connecting the SO pin on one device to the SI pin of the
next device in the chain. This application note details one
example of source code that is used to communicate with
eight daisy chained devices.
AN757: Interfacing Microchip’s MCP41XXX/MCP4XXX
Digital Potentiometer to the Motorola 68HC12
Microcontroller
Communication between the MCP41XXX and MCP42XXX
family of digital potentiometers and the Motorola 68HC12
family of microcontrollers is discussed. These devices
communicate using a standard 3-wire SPI compatible
interface. Specifi cally, the MC68HC912B32 evaluation board
was used.
AN1080: Understanding Digital Potentiometer Resistance
Variations
This application note discusses how process, voltage and
temperature effect the resistor network’s characteristics,
specifications and techniques to improve system
performance.
AN1316: Using Digital Potentiometers for Programmable
Amplifi er Gain
This Application Note will discuss implementations of
programmable gain circuits using an op amp and a digital
potentiometer. This discussion will include implementation
details for the digital potentiometer’s resistor network. It is
important to understand these details to understand the
effects on the application.
Information subject to change. The Microchip name and logo, the Microchip logo and PIC are registered trademarks and ICSP, PICkit,
PICtail and WiperLock are trademarks of Microchip Technology Incorporated in the U.S.A. All other trademarks mentioned herein are
property of their respective companies. © 2010 Microchip Technology Inc. All Rights Reserved. Printed in the USA. 12/10
DS22017C
*DS22017C
Microchip Technology Inc.
2355 W. Chandler Blvd.
Chandler, AZ 85224-6199
www.microchip.com
Support
Microchip is committed to supporting its customers
in developing products faster and more efficiently. We
maintain a worldwide network of field applications
engineers and technical support ready to provide product
and system assistance. In addition, the following service
areas are available at www.microchip.com:
■ Support link provides a way to get questions
answered fast: http://support.microchip.com
■ Sample link offers evaluation samples of any
Microchip device: http://sample.microchip.com
■ Forum link provides access to knowledge base and
peer help: http://forum.microchip.com
■ Buy link provides locations of Microchip Sales Channel
Partners: www.microchip.com/sales
Training
If additional training interests you, then Microchip can
help. We continue to expand our technical training options,
offering a growing list of courses and in-depth curriculum
locally, as well as significant online resources – whenever
you want to use them.
■ Regional Training Centers: www.microchip.com/rtc
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■ Resources from our Distribution and Third Party Partners
www.microchip.com/training
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