DS1804Z-010 - Dallas Semiconductor

DS1804

NV Trimmer Potentiometer

DS1804

121797 1/6

FEATURES

•Single 100–Position Linear Taper Potentiometer

•Nonvolatile “On–Demand” Wiper Storage

•Operates from 3V or 5V supplies

•Up/Down, Increment Controlled Interface

•Resistance Values: 10KΩ, 50KΩ, and 100KΩ

•Available in 8–Pin (300 Mil) DIP , 8–Pin (150 Mil) SOIC

packages

•Operating Temperature:

– Industrial: –40°C to 85°C

PIN ASSIGNMENT

VCC

INC

U/D

GND

8–PIN DIP (300 MIL)

8–PIN SOIC (150 MIL)

See Mech. Drawings

Section

PIN DESCRIPTION

H – High–End of Resistor

L – Low–End of Resistor

W – Wiper Terminal

VCC – 3V or 5V Power Supply Input

CS – Chip Select

U/D – Up/Down Control Input

INC – Increment/Decrement

Counter Input

GND – Ground

DESCRIPTION

The DS1804 is a nonvolatile digital potentiometer hav-

ing 100 positions. The device provides an ideal method

for low–cost trimming applications using a CPU or

manual control input with minimal external circuitry.

Wiper position of the DS1804 can be stored in EEPROM

memory on demand. The device’s wiper position is

manipulated by a 3–terminal port that provides an incre-

ment/decrement counter controlled interface. This port

consists of the control inputs CS, INC, and U/D.

The DS1804 is available in three resistor grades which

include a 10KΩ, 50KΩ, and 100KΩ. The device is pro-

vided in an industrial temperature grade. Additionally,

the DS1804 will operate from 3V or 5V supplies and is

ideal for portable application requirements. Two pack-

aging options are available and include the 8–pin (300

mil) DIP and 8–Pin (150 mil) SOIC.

DS1804

121797 2/6

OPERATION

The DS1804 is a single nonvolatile potentiometer. The

device has a total of 100 tap–points including the L– and

H– terminals. A total of 99 resistive segments exist

between the L– and H– terminals. These tap–points are

accessible to the W–terminal whose position is con-

trolled via a 3–terminal control port. A block diagram of

the DS1804 is shown in Figure 1.

The 3–terminal port of the DS1804 provides an incre-

ment/decrement interface which is activated via a chip

select input. This interface consists of the input signals

CS, INC, and U/D. These input signals control a 7–bit

up/down counter. The output of the 7–bit up/down

counter controls a 1 of 100 decoder to select wiper posi-

tion. Additionally , this interface provides for a wiper stor-

age operation using the CS and INC input control pins.

The timing diagram for the 3–terminal interface control

is shown in Figure 2.

PIN DESCRIPTIONS

VCC – Power Supply Terminal. The DS1804 will sup-

port supply voltages ranging from +2.7 to +5.5 volts.

GND – Ground Terminal.

H – High–end of Resistor. This is the high–end terminal

of the potentiometer . It is not required that this terminal

be connected to a potential greater than the L–terminal.

Voltage applied to the H–terminal can not exceed the

power–supply voltage, VCC, or go below ground.

L – Low–end of Resistor –This is the low–end terminal

of the potentiometer . It is not required that this terminal

be connected to a potential less than the H–terminal.

Voltage applied to the L–terminal cannot exceed the

power–supply voltage, VCC, or go below ground.

W – Wiper of the Potentiometer. This pin is the wiper

terminal of the potentiometer. Its position on the resistor

array is controlled by the 3–terminal control port. Volt-

age applied to the W–terminal cannot exceed the pow-

er–supply voltage, VCC, or go below ground.

CS – Chip Select. The CS input is used to activate the

control port of the DS1804. This input is active low.

When in a high–state, activity on the INC and U/D port

pins will not affect or change wiper position.

INC – Wiper Movement Control. This input provides for

wiper position changes when the CS pin is low. Wiper

position changes of the W–terminal will occur one posi-

tion per high–to–low transition of this input signal. Posi-

tion changes will not occur if the CS pin is in a high–

state.

U/D – Up/Down Control. This input sets the direction of

wiper movement. When in a high–state and CS is low ,

any high–to–low transition on INC will cause a one

position movement of the wiper towards the H–terminal.

When in a low–state and CS is low, any high–to–low

transitions on INC will cause the position of the wiper to

move towards the L–terminal.

DS1804 BLOCK DIAGRAM Figure 1

3-TERMINAL

GND

CONTROL LOGIC

NV MEMORY

100-TO-1 MULTIPLEXER

POS 99

POS 0

INC

U/D

VCC

UNIT

CONTROL PORT

DS1804

121797 3/6

POWER–UP/POWER–DOWN CONDITIONS

On power–up the DS1804 will load the value of

EEPROM memory into the wiper position register (or 1

of 100 decoder). The value of this register can then be

set to another wiper position if desired, by using the

3–terminal control port. On power–up, wiper position

will be loaded within a maximum time period of 500 µs

once the power–supply is stable. Additionally, the 3–

terminal interface port will be active after 50 ms.

On power–down, the wiper position register data will be

lost. On the next device power–up, the value of

EEPROM memory will be loaded into the wiper position

On shipment from the factory, Dallas Semiconductor

does not guarantee a specified EEPROM memory

value. This value should be set by the customer as

needed. The next section discusses wiper storage

operation for the DS1804.

NONVOLATILE WIPER STORAGE

Wiper position of the DS1804 can be stored using the

INC and CS inputs. Storage of the wiper position takes

place, whenever the CS input transitions from low–to–

high while the INC is high. Once this condition has

occurred the value of the current wiper position will be

written to EEPROM memory.

The DS1804 is specified to accept 50,000 writes to

EEPROM before a wear–out condition. After wear out

the DS1804 will still function and wiper position can be

changed during powered conditions using the 3–termi-

nal control port. However, on power–up the wiper–posi-

tion will be indeterminate.

ONE TIME PROGRAMMABILITY (OTP)

The DS1804 can be easily used as an OTP device. The

user of the DS1804 can trim the desired value of the

wiper position and set this position for storage as

described above. Any activity through the 3–terminal

port can then be prevented by connecting the CS input

pin to VCC. Also, an OTP application does not

adversely affect the number of times EEPROM is writ-

ten, since EEPROM will only be loaded and

not written

during a power–up or power–down condition.

On power–up the DS1804 will load the current value of

EEPROM memory into the wiper position register.

DS1804

121797 4/6

ABSOLUTE MAXIMUM RATINGS*

Voltage on Any Pin Relative to Ground –1.0V to +7.0V

Operating Temperature –40°C to +85°C; industrial

Storage Temperature –55°C to +125°C

Soldering Temperature 260°C for 10 seconds

* This is a stress rating only and functional operation of the device at these or any other conditions above those

indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating

conditions for extended periods of time may affect reliability.

RECOMMENDED DC OPERATING CONDITIONS (–40°C to +85°C)

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

Supply Voltage VCC +2.7 5.5 V 1

Input Logic 1 VIH 2.0 VCC+0.5 V 1, 2

Input Logic 0 VIL –0.5 +0.8

+0.6 V1, 15

Resistor Inputs L, H, W GND–0.5 VCC+0.5 V 1, 3

DC ELECTRICAL CHARACTERISTICS (–40°C to +85°C; VCC=2.7V to 5.5V)

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

Supply Current ICC 400 µA 4

Input Leakage ILI –1 +1 µA

Wiper Resistance RW400 1000 Ω

Wiper Current IW1 mA

Standby Current

3 Volts

5 Volts

ISTBY 10

20 40 µA

µA

Wiper Load T ime tWLT 500 µs 6

Power–Up T ime tPU 50 ms 14

ANALOG RESISTOR CHARACTERISTICS (–40°C to +85°C; VCC=2.7V to 5.5V)

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

Total Resistance 10

100 KΩ7

End–to–End Resistor Tolerance –20 +20 % 8

Absolute Linearity ±0.6 LSB 9

Relative Linearity ±0.25 LSB 10

–3 dB Cutoff Frequency fcutoff MHz 11

Temperature Coefficient 650 ppm/°C

DS1804

121797 5/6

CAPACITANCE (25°C; VCC=2.7V to 5.5V)

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

Input Capacitance CIN 5pF 12

Output Capacitance COUT 7 pF 12

AC ELECTRICAL CHARACTERISTICS (–40°C to +85°C; VCC=2.7V to 5.5V)

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

CS to INC Setup tCI 50 ns 13

U/D to INC Setup tDI 100 ns 13

INC Low Period tIL 50 ns 13

INC High Period tIH 100 ns 13

INC Inactive to CS Inactive tIC 500 ns 13

CS Deselect T ime tCPH 100 ns 13

Wiper Change to INC Low tIW 200 ns 13

INC Rise and Fall T imes tR, tF500 µs 13

INC Low to CS Inactive tIK 50 ns 16

Wiper Storage T ime tWST 10 ms 13, 17

NOTES:

1. All voltages are referenced to ground.

2. Valid for VCC = 5V only.

3. Resistor input voltages cannot go below ground or exceed VCC by the amounts as shown in the table.

4. Maximum current specifications are based on the clock rate of INC input. This specification represents the cur-

rent required when changing the wiper position.

5. Standby current levels apply when all inputs are driven to appropriate supply levels. CS, INC, U/D = VCC.

6. Wiper load time is specified as the time required for the DS1804 to load the wiper position with the contents of

nonvolatile memory once VCC has reached a stable operating voltage equal to or greater than 2.7V.

7. The DS1804 is available in three resistor values. These include the DS1804–010; 10KΩ , the DS1804–050 50KΩ;

and the DS1804–100 100KΩ.

8. The end–to–end resistance tolerance of the DS1804 can be expected to shift with temperature. However, this

change will not exceed ±20% of the nominal resistor value of the part.

9. Absolute linearity is used to compare measured wiper voltage versus expected wiper voltage as determined by

wiper position. The DS1804 is specified to provide an absolute linearity of ±0.60 LSB

10.Relative linearity is used to determined the change in voltage between successive tap positions. The DS1804

is specified to provide a relative linearity specification of ±0.25 LSB.

11. –3 dB cutoff frequency characteristics for the DS1804 depend on potentiometer total resistance. DS1804–010,

1 MHz, DS1804–050; 200 KHz, and DS1804–100; 100 KHz.

DS1804

121797 6/6

12.Capacitance values apply at 25°C.

13.See Figure 2.

14.Power–up time is specified as the time required before the 3–terminal control becomes active after a stable power

supply level has been reached.

15.At VCC = 2.7V, VIL = 0.8V

16.The INC low to CS inactive is specified to be 50 ns minimum. This is the transition condition which allows the

DS1804 3–terminal port to become inactive without writing the EEPROM memory of the part.

17.Wiper Storage Time, tWST

, is the time require for the DS1804 to write EEPROM memory for storage of a new

wiper position. The maximum time required to accomplish this task is specified at 10 ms.

DS1804 ORDERING INFORMATION

ORDERING NUMBER PACKAGE OPERATING TEMP. VERSION

DS1804-010 8L DIP –40°C TO +85°C 10KΩ

DS1804-050 8L DIP –40°C TO +85°C 50KΩ

DS1804-100 8L DIP –40°C TO +85°C 100KΩ

DS1804Z-010 8L SOIC (150 MIL) –40°C TO +85°C 10KΩ

DS1804Z-050 8L SOIC (150 MIL) –40°C TO +85°C 50KΩ

DS1804Z-100 8L SOIC (150 MIL) –40°C TO +85°C 100KΩ

3–TERMINAL INTERFACE TIMING DIAGRAM Figure 2

tCI

tIW

tIK

tDI

tIL

tIH tIC tWPS

tCPH

WIPER STORAGE WIPER NON–STORAGE

CONDITION CONDITION

INC

U/D