_______________General Description
The MAX5154/MAX5155 low-power, serial, voltage-out-
put, dual 12-bit digital-to-analog converters (DACs)
consume only 500µA from a single +5V (MAX5154) or
+3V (MAX5155) supply. These devices feature Rail-to-
Rail®output swing and are available in a space-saving
16-pin QSOP package. To maximize the dynamic
range, the DAC output amplifiers are configured with an
internal gain of +2V/V.
The 3-wire serial interface is SPI™/QSPI™ and
Microwire™ compatible. Each DAC has a double-
buffered input organized as an input register followed
by a DAC register, which allows the input and DAC reg-
isters to be updated independently or simultaneously
with a 16-bit serial word. Additional features include
programmable shutdown (2µA), hardware-shutdown
lockout (PDL), a separate reference voltage input for
each DAC that accepts AC and DC signals, and an
active-low clear input (CL) that resets all registers and
DACs to zero. These devices provide a programmable
logic pin for added functionality, and a serial-data out-
put pin for daisy chaining.
________________________Applications
Industrial Process Control Remote Industrial Controls
Digital Offset and Gain Microprocessor-
Adjustment Controlled Systems
Motion Control Automatic Test
Equipment (ATE)
____________________________Features
♦12-Bit Dual DAC with Internal Gain of +2V/V
♦Rail-to-Rail Output Swing
♦12µs Settling Time
♦Single-Supply Operation: +5V (MAX5154)
+3V (MAX5155)
♦Low Quiescent Current: 500µA (normal operation)
2µA (shutdown mode)
♦SPI/QSPI and Microwire Compatible
♦Available in Space-Saving 16-Pin QSOP Package
♦Power-On Reset Clears Registers and DACs
to Zero
♦Adjustable Output Offset
MAX5154/MAX5155
Low-Power, Dual, 12-Bit Voltage-Output DACs
with Serial Interface
________________________________________________________________
Maxim Integrated Products
1
19-1316; Rev 1; 12/97
______________Ordering Information
Rail-to-Rail is a registered trademark of Nippon Motorola Ltd. SPI and QSPI are trademarks of Motorola, Inc.
Microwire is a trademark of National Semiconductor Corp.
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800
For small orders, phone 408-737-7600 ext. 3468.
REFA
VDD
AGND
DGNDPDLCL
DOUT
16-BIT
SHIFT
REGISTER
SR
CONTROL
INPUT
REG A
INPUT
REG B
SCLK UPO REFB
DINCS
DAC B
DAC A
DAC
REG A
LOGIC
OUTPUT
DECODE
CONTROL
DAC
REG B
MAX5154
MAX5155
OUTB
R
R
R
R
OSB
OUTA
OSA
_________________________________________________________Functional Diagram
Ordering Information continued at end of data sheet.
Pin Configuration appears at end of data sheet.
INL
(LSB)
PIN-PACKAGETEMP. RANGEPART
±1/2
±1
±1/2
16 QSOP
16 Plastic DIP
16 Plastic DIP0°C to +70°C
0°C to +70°C
0°C to +70°CMAX5154ACEE
MAX5154BCPE
MAX5154ACPE
±116 QSOP0°C to +70°CMAX5154BCEE
MAX5154/MAX5155
Low-Power, Dual, 12-Bit Voltage-Output DACs
with Serial Interface
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS—MAX5154
(VDD = +5V ±10%, VREFA = VREFB = 2.048V, RL= 10kΩ, CL= 100pF, TA= TMIN to TMAX, unless otherwise noted. Typical values are
at TA= +25°C (OS_ tied to AGND for a gain of +2V/V).)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
VDD to AGND............................................................-0.3V to +6V
VDD to DGND ...........................................................-0.3V to +6V
AGND to DGND..................................................................±0.3V
OSA, OSB to AGND........................(AGND - 4V) to (VDD + 0.3V)
REF_, OUT_ to AGND.................................-0.3V to (VDD + 0.3V)
Digital Inputs (SCLK, DIN, CS, CL, PDL)
to DGND............................................................(-0.3V to +6V)
Digital Outputs (DOUT, UPO)
to DGND................................................-0.3V to (VDD + 0.3V)
Maximum Current into Any Pin.........................................±20mA
Continuous Power Dissipation (TA= +70°C)
Plastic DIP (derate 10.5mW/°C above +70°C) ...........842mW
QSOP (derate 8.30mW/°C above +70°C)...................667mW
CERDIP (derate 10.00mW/°C above +70°C)..............800mW
Operating Temperature Ranges
MAX515_ _C_ E .................................................0°C to +70°C
MAX515_ _E_ E ..............................................-40C° to +85°C
MAX515_ _MJE.............................................-55°C to +125°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10sec).............................+300°C
(Note 1)
Input code = 0000 hex,
VREF_ = (VDD - 1.4Vp-p) at 1kHz
Input code = 1FFE hex,
VREF_ = 0.67Vp-p at 2.5VDC
4.5V ≤VDD ≤5.5V
Minimum with code 1554 hex
Normalized to 2.048V
Guaranteed monotonic
Code = 6
Normalized to 2.048V
dB-82Reference Feedthrough
kHz300Reference 3dB Bandwidth
kΩ14 20RREF
Reference Input Resistance REFReference Input Range V0 VDD - 1.4
±1 LSB
±1/2
INL
Bits12Resolution
Integral Nonlinearity
PSRR
VDD Power-Supply
Rejection Ratio µV/V20 260
ppm/°C4Gain-Error Tempco
LSB±1DNLDifferential Nonlinearity mV±6Vos
Offset Error ppm/°C4TCVos
Offset Tempco LSB-0.2 ±3Gain Error
MAX5154A
MAX5154B
CONDITIONS UNITSMIN TYP MAXSYMBOLPARAMETER
Input code = 1FFE hex,
VREF_ = 1Vp-p at 1.25VDC, f = 25kHz dB75SINAD
Signal-to-Noise plus
Distortion Ratio
CL, PDL, CS, DIN, SCLK V0.8VIL
Input Low Voltage
VIN = 0V to VDD µA0.001 ±1IIN
Input Leakage Current pF8CIN
Input Capacitance
mV200VHYS
Input Hysteresis
CL, PDL, CS, DIN, SCLK V3VIH
Input High Voltage
STATIC PERFORMANCE
REFERENCE INPUT
MULTIPLYING-MODE PERFORMANCE
DIGITAL INPUTS
MAX5154/MAX5155
Low-Power, Dual, 12-Bit Voltage-Output DACs
with Serial Interface
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS—MAX5154 (continued)
(VDD = +5V ±10%, VREFA = VREFB = 2.048V, RL= 10kΩ, CL= 100pF, TA= TMIN to TMAX, unless otherwise noted. Typical values are
at TA= +25°C (OS_ tied to AGND for a gain of +2V/V).)
Note 1: Accuracy is specified from code 6 to code 4095.
Note 2: Accuracy is better than 1LSB for VOUT_ greater than 6mV and less than VDD - 50mV. Guaranteed by PSRR test at the end
points.
Note 3: Digital inputs are set to either VDD or DGND, code = 0000 hex, RL= ∞.
Note 4: SCLK minimum clock period includes the rise and fall times.
CS = VDD, fDIN = 100kHz, VSCLK = 5Vp-p
ISOURCE = 2mA
(Note 4)
(Note 3)
(Note 3)
ns
Rail-to-rail (Note 2)
To 1/2LSB of full-scale, VSTEP = 4V
40
ISINK = 2mA
tCL
SCLK Pulse Width Low
CONDITIONS
ns40tCH
SCLK Pulse Width High
nV-s5Digital Crosstalk nV-s5Digital Feedthrough µs25Time Required to Exit Shutdown kΩ24 34ROS_
OSA or OSB Input Resistance
ns100tCP
SCLK Clock Period
µA0 ±1Reference Current in Shutdown
µA2 10IDD(SHDN)
Power-Supply Current
in Shutdown
mA0.5 0.65IDD
Power-Supply Current V4.5 5.5VDD
Positive Supply Voltage
ns40tDS
SDI Setup Time
ns
VVDD - 0.5VOH
Output High Voltage
0tCSH
SCLK Rise to CS Rise
Hold Time
ns40tCSS
CS Fall to SCLK Rise
Setup Time
CLOAD = 200pF
V0 to VDD
Output Voltage Swing µs15Output Settling Time
CLOAD = 200pF
ns80
V0.13 0.40VOL
Output Low Voltage
V/µs0.75SRVoltage Output Slew Rate
UNITSMIN TYP MAXSYMBOLPARAMETER
tDO2
SCLK Fall to DOUT
Valid Propagation Delay
ns80tDO1
SCLK Rise to DOUT
Valid Propagation Delay
ns0tDH
SDI Hold Time
ns100tCSW
CS Pulse Width High ns40tCS1
CS Rise to SCLK Rise Hold ns10tCS0
SCLK Rise to CS Fall Delay
DIGITAL OUTPUTS (DOUT, UPO)
DYNAMIC PERFORMANCE
POWER SUPPLIES
TIMING CHARACTERISTICS
Resolution
MAX5154/MAX5155
Low-Power, Dual, 12-Bit Voltage-Output DACs
with Serial Interface
4 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS—MAX5155
(VDD = +2.7V to +3.6V, VREFA = VREFB = 1.25V, RL= 10kΩ, CL= 100pF, TA= TMIN to TMAX, unless otherwise noted. Typical values
are at TA= +25°C (OS_ pins tied to AGND for a gain of +2V/V).)
nV-s5Digital Crosstalk
CS = VDD, fDIN = 100kHz, VSCLK = 3Vp-p nV-s5Digital Feedthrough
µs25
Time Required for Valid
Operation after Shutdown
Input code = 1FFE hex,
VREF_ = 1Vp-p at 1VDC, f = 15kHz dB73SINAD
Signal-to-Noise plus
Distortion Ratio
(Note 5)
Input code = 0000 hex,
VREF_ = (VDD - 1.4)Vp-p at 1kHz
Input code = 1FFE hex,
VREF_ = 0.67Vp-p at 0.75VDC
CL, PDL, CS, DIN, SCLK
2.7V ≤VDD ≤3.6V
Minimum with code 1554 hex
Normalized to 1.25V
Guaranteed monotonic
Code = 10
Normalized to 1.25V
V0.8VIL
Input Low Voltage
VIN = 0V to VDD µA0 ±1IIN
Input Leakage Current pF8
CIN
Input Capacitance
mV200VHYS
Input Hysteresis
CL, PDL, CS, DIN, SCLK V
dB-82Reference Feedthrough
kHz300Reference 3dB Bandwidth
2.2VIH
Input High Voltage
kΩ14 20RREF
Reference Input Resistance
±2
MAX5155A
MAX5155B LSB
±1
INL
Bits12
Integral Nonlinearity
PSRR
VDD Power-Supply
Rejection Ratio µV/V40 320
ppm/°C6.5Gain-Error Tempco
LSB±1DNLDifferential Nonlinearity mV±6Vos
Offset Error ppm/°C6.5TCVos
Offset Tempco LSB-0.2 ±4Gain Error
Rail-to-rail (Note 6)
ISOURCE = 2mA
kΩ24 34ROS_
OSA or OSB Input Resistance V0 to VDD
Output Voltage Swing
VVDD - 0.5VOH
Output High Voltage
CONDITIONS UNITSMIN TYP MAXSYMBOLPARAMETER
REFReference Input Range V0 VDD - 1.4
DIGITAL OUTPUTS (DOUT, UPO)
ISINK = 2mA V0.13 0.4VOL
Output Low Voltage
To 1/2LSB of full-scale, VSTEP = 2.5V µs15Output Settling Time V/µs0.75SRVoltage Output Slew Rate
REFERENCE INPUT (VREF)
MULTIPLYING-MODE PERFORMANCE
DIGITAL INPUTS
STATIC PERFORMANCE
DYNAMIC PERFORMANCE
MAX5154/MAX5155
Low-Power, Dual, 12-Bit Voltage-Output DACs
with Serial Interface
_______________________________________________________________________________________ 5
Note 5: Accuracy is specified from code 10 to code 4095.
Note 6: Accuracy is better than 1LSB for VOUT greater than 6mV and less than VDD - 80mV. Guaranteed by PSRR test at the end
points.
Note 7: Digital inputs are set to either VDD or DGND, code = 0000 hex, RL= ∞.
ELECTRICAL CHARACTERISTICS—MAX5155 (continued)
(VDD = +2.7V to +3.6V, VREFA = VREFB = 1.25V, RL= 10kΩ, CL= 100pF, TA= TMIN to TMAX, unless otherwise noted. Typical values
are at TA= +25°C (OS_ pins tied to AGND for a gain of +2V/V).)
CLOAD = 200pF ns120tDO2
SCLK Fall to DOUT Valid
Propagation Delay
ns100tCSW
CS Pulse Width High ns40tCS1
CS Rise to SCLK Rise Hold ns10tCS0
SCLK Rise to CS Fall Delay
CONDITIONS UNITS
(Note 7) mA0.45 0.6IDD
Power-Supply Current
(Note 7) µA1 8IDD (SHDN)
Power-Supply Current
in Shutdown
µA
MIN TYP MAX
0 ±1Reference Current in Shutdown
(Note 4) ns100
SYMBOLPARAMETER
tCP
SCLK Clock Period ns40tCH
SCLK Pulse Width High ns40tCL
SCLK Pulse Width Low
ns40tCSS
CS Fall to SCLK Rise
Setup Time
ns0tCSH
SCLK Rise to CS Rise Hold Time ns50tDS
SDI Setup Time ns0tDH
SDI Hold Time
CLOAD = 200pF ns120tDO1
SCLK Rise to DOUT Valid
Propagation Delay
V2.7 3.6VDD
Positive Supply Voltage
POWER SUPPLIES
TIMING CHARACTERISTICS
MAX5154/MAX5155
Low-Power, Dual, 12-Bit Voltage-Output DACs
with Serial Interface
6 _______________________________________________________________________________________
__________________________________________Typical Operating Characteristics
(VDD = +5V, RL= 10kΩ, CL= 100pF, OS_ pins tied to AGND, TA= +25°C, unless otherwise noted.)
-20
-16
-18
-12
-14
-8
-10
-6
-2
-4
0
1 370 740 1110 1480 1850
REFERENCE VOLTAGE INPUT
FREQUENCY RESPONSE
MAX5154/5155toc01
FREQUENCY (kHz)
RELATIVE OUTPUT (dB)
VREF = 0.67Vp-p @ 2.5VDC
CODE = 1FFE (HEX)
400
450
550
500
650
600
700
-55 5-15-35 4525 65 10585 125
SUPPLY CURRENT vs. TEMPERATURE
MAX5154/5155 toc02
TEMPERATURE (°C)
SUPPLY CURRENT (µA)
VREF = 2.048V
RL = ∞
CODE = 1FFE (HEX)
CODE = 0000 (HEX)
-30
-80 1 10 100
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
-70
MAX5154/5155 toc03
FREQUENCY (kHz)
THD + NOISE (dB)
-60
-50
-40
VREF = 1Vp-p @ 2.5VDC
CODE = 1FFE (HEX)
0
0.1 1 10 100
FULL-SCALE ERROR vs. RESISTIVE LOAD
-1.25
-1.00
-1.50
-0.75
-0.50
-0.25
0.25
0.50
MAX5154/5155 toc04
RL (kΩ)
FULL-SCALE ERROR (LSB)
VREF = 2.048V
-100
-80
-90
-60
-70
-40
-50
0.5 1.6 2.7 3.8 4.9 6.0
-30
-10
-20
0OUTPUT FFT PLOT
MAX5154/5155 toc07
VREF = 2.45Vp-p @ 1.225VDC
f = 1kHz
CODE = 1FFE (HEX)
NOTE: RELATIVE TO FULL-SCALE
FREQUENCY (kHz)
RELATIVE OUTPUT (dB)
-150
-130
-140
-110
-120
-90
-100
-80
-60
-70
-50
0.5 1.5 2.0 2.51.0 3.0 3.5 4.0 5.04.5 5.5
REFERENCE FEEDTHROUGH AT 1kHz
MAX5154/5155 toc05
FREQUENCY (kHz)
RELATIVE OUTPUT (dB)
VREF = 3.6Vp-p @ 1.88VDC
CODE = 0000 (HEX)
0
1
2
3
4
5
6
-55 5 25-15-35 45 65 85 105 125
SHUTDOWN CURRENT
vs. TEMPERATURE
MAX5154/5155 toc06
TEMPERATURE (°C)
SHUTDOWN CURRENT (µA)
VREF = 1V
DYNAMIC RESPONSE RISE TIME
MAX5154/5155 toc08
2µs/div
OUT_
1V/div
5V/div
CS
VREF = 2.048V
2µs/div
DYNAMIC RESPONSE FALL TIME
MAX5154/5155 toc09
OUT_
1V/div
5V/div
CS
VREF = 2.048V
MAX5154
MAX5154/MAX5155
Low-Power, Dual, 12-Bit Voltage-Output DACs
with Serial Interface
_______________________________________________________________________________________ 7
_____________________________Typical Operating Characteristics (continued)
(VDD = +3V, RL= 10kΩ, CL= 100pF, OS_pins tied to AGND, TA= +25°C, unless otherwise noted.)
400
440
420
500
480
460
540
520
560
-55 5 25-35 -15 45 65 85 105 125
SUPPLY CURRENT vs. TEMPERATURE
MAX5154/5155 toc11
TEMPERATURE (°C)
SUPPLY CURRENT (µA)
VREF = 1V
RL = ∞ CODE = 1FFE (HEX)
CODE = 0000 (HEX)
-30
-80 1 10 100
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
-70
MAX5154/5155 toc12
FREQUENCY (kHz)
THD + NOISE (dB)
-60
-50
-40
VREF = 1Vp-p @ 1VDC
CODE = 1FFE (HEX)
0.25
-1.25 0.1 1 10 100
FULL-SCALE ERROR vs. RESISTIVE LOAD
-0.50
-0.75
-1.00
-0.25
0
MAX5154/5155 toc13
RL (kΩ)
FULL-SCALE ERROR (LSB)
VREF = 1.25V
-100
-80
-90
-60
-70
-40
-50
-30
-10
-20
0
0.5 2.7 3.8 4.91.6 6.0
OUTPUT FFT PLOT
MAX5154/5155toc16
FREQUENCY (kHz)
RELATIVE OUTPUT (dB)
VREF = 1.4Vp-p @ 0.75VDC
f = 1kHz
CODE = 1FFE (HEX)
-150
-130
-140
-110
-120
-90
-100
-80
-60
-70
-50
0.5 1.5 2.0 2.51.0 3.0 3.5 4.0 5.04.5 5.5
REFERENCE FEEDTHROUGH AT 1kHz
MAX5154/5155 toc14
FREQUENCY (kHz)
RELATIVE OUTPUT (dB)
VREF = 1.6Vp-p @ 0.88VDC
CODE = 0000 (HEX)
1.2
1.0
1.6
1.4
2.0
1.8
2.2
2.4
2.8
2.6
3.0
-55 -15 5 25-35 45 65 85 105 125
SHUTDOWN CURRENT
vs. TEMPERATURE
MAX5154/5155 toc15
TEMPERATURE (°C)
SHUTDOWN CURRENT (µA)
VREF = 1V
RL = ∞
DYNAMIC RESPONSE FALL TIME
MAX5154/5155 toc18
VREF = 1.25V
2µs/div
OUT_
500mV/div
CS
2V/div
MAX5155
DYNAMIC RESPONSE RISE TIME
MAX5154/5155 toc17
2µs/div
VREF = 1.25V
OUT_
500mV/div
2V/div
CS
MAX5154/MAX5155
Low-Power, Dual, 12-Bit Voltage-Output DACs
with Serial Interface
8 _______________________________________________________________________________________
_____________________________Typical Operating Characteristics (continued)
(VDD = +5V (MAX5154), VDD = +3V (MAX5155), RL= 10kΩ, CL= 100pF, OS_ pins tied to AGND, unless otherwise noted.)
0.40
0.45
0.50
0.55
0.60
4.50 4.75 5.00 5.25 5.50
MAX5154
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX5154/5155toc19
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
CODE = 1FFE (HEX)
CODE = OOOO (HEX)
0.40
0.45
0.50
0.55
0.60
2.7 3.0 3.3 3.6
MAX5155
SUPPLY CURRENT vs. SUPPLY VOLTAGE
MAX5154/5155toc20
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
CODE = 1FFE (HEX)
CODE = OOOO (HEX)
OUTB
200µV/div
AC COUPLED
OUTA
5V/div
MAX5154
ANALOG CROSSTALK
MAX5154/5155 toc22
VREF = 2.048V, GAIN = +2V/V, CODE = 1FFE HEX
250µs/div
MAX5154
DIGITAL FEEDTHROUGH
MAX5154/5155 toc23
OUTA
500µV/div
AC COUPLED
SCLK
5V/div
2.5µs/div
5µs/div
MAX5154
MAJOR-CARRY TRANSITION
MAX5154/5155 toc21
TRANSITION FROM 1000 (HEX) TO 0FFE (HEX)
OUT_
50mV/div
AC COUPLED
2V/div
CS
MAX5154/MAX5155
_______________Detailed Description
The MAX5154/MAX5155 dual, 12-bit, voltage-output
DACs are easily configured with a 3-wire serial inter-
face. These devices include a 16-bit data-in/data-out
shift register, and each DAC has a double-buffered
input composed of an input register and a DAC register
(see
Functional Diagram
). In addition, trimmed internal
resistors produce an internal gain of +2V/V that maxi-
mizes output voltage swing. The amplifier’s offset-adjust
pin allows for a DC shift in the DAC’s output.
Both DACs use an inverted R-2R ladder network that pro-
duces a weighted voltage proportional to the input volt-
age value. Each DAC has its own reference input to
facilitate independent full-scale values. Figure 1 depicts a
simplified circuit diagram of one of the two DACs.
Reference Inputs
The reference inputs accept both AC and DC values
with a voltage range extending from 0V to (VDD - 1.4V).
Determine the output voltage using the following equa-
tion (OS_ = AGND):
VOUT = (VREF x NB / 4096) x 2
where NB is the numeric value of the DAC’s binary input
code (0 to 4095) and VREF is the reference voltage.
The reference input impedance ranges from 14kΩ(1554
hex) to several giga ohms (with an input code of 0000
hex). The reference input capacitance is code dependent
and typically ranges from 15pF with an input code of all
zeros to 50pF with a full-scale input code.
Output Amplifier
The output amplifiers on the MAX5154/MAX5155 have
internal resistors that provide for a gain of +2V/V when
OS_ is connected to AGND. These resistors are
trimmed to minimize gain error. The output amplifiers
have a typical slew rate of 0.75V/µs and settle to
1/2LSB within 15µs, with a load of 10kΩin parallel with
100pF. Loads less than 2kΩdegrade performance.
The OS_ pin can be used to produce an adjustable off-
set voltage at the output. For instance, to achieve a 1V
offset, apply -1V to the OS_ pin to produce an output
range from 1V to (1V + VREF x 2). Note that the DAC’s
output range is still limited by the maximum output volt-
age specification.
Power-Down Mode
The MAX5154/MAX5155 feature a software-program-
mable shutdown mode that reduces the typical supply
current to 2µA. The two DACs can be shutdown inde-
pendently, or simultaneously using the appropriate pro-
gramming command. Enter shutdown mode by writing
the appropriate input-control word (Table 1). In shut-
down mode, the reference inputs and amplifier out-
puts become high impedance, and the serial
interface remains active. Data in the input registers is
MAX5154/MAX5155
Low-Power, Dual, 12-Bit Voltage-Output DACs
with Serial Interface
_______________________________________________________________________________________ 9
Digital GroundDGND9
Serial-Data OutputDOUT10
User-Programmable OutputUPO11
Power-Down Lockout. The device can-
not be powered down when PDL is low.
PDL
12
Reference for DAC BREFB13
Active-Low Clear Input. Resets all reg-
isters to zero. DAC outputs go to 0V.
CL
5
Chip-Select Input
CS
6
Serial-Data Input DIN7
Serial Clock Input SCLK8
Reference for DAC A REFA4
DAC A Offset AdjustmentOSA3
PIN
DAC A Output Voltage OUTA2
Analog Ground AGND1
FUNCTIONNAME
14 OSB DAC B Offset Adjustment
15 OUTB DAC B Output Voltage
16 VDD Positive Power Supply
OUT_
OS_
R
R
SHOWN FOR ALL 1s ON DAC
D0 D9 D10 D11
2R 2R 2R 2R 2R
R R R
REF_
AGND
Figure 1. Simplified DAC Circuit Diagram
_____________________Pin Description
MAX5154/MAX5155
saved, allowing the MAX5154/MAX5155 to recall the
output state prior to entering shutdown when returning
to normal mode. Exit shutdown by recalling the previ-
ous condition or by updating the DAC with new infor-
mation. When returning to normal operation (exiting
shutdown), wait 20µs for output stabilization.
Serial Interface
The MAX5154/MAX5155 3-wire serial interface is com-
patible with both Microwire (Figure 2) and SPI/QSPI
(Figure 3) serial-interface standards. The 16-bit serial
input word consists of an address bit, two control bits,
12 bits of data (MSB to LSB), and one sub bit as shown
in Figure 4. The address and control bits determine the
MAX5154/ MAX5155’s response, as outlined in Table 1.
Low-Power, Dual, 12-Bit Voltage-Output DACs
with Serial Interface
10 ______________________________________________________________________________________
FUNCTION
A0 C1 C0 D11.......................D0
(MSB) (LSB)
0 0 1 12-bit DAC data Load input register A; DAC registers are unchanged.
0 1 1 12-bit DAC data Load all DAC registers from the shift register
(start up both DACs with new data.).
1 1 0 12-bit DAC data Load input register B; all DAC registers are updated.
0 1 0 12-bit DAC data Load input register A; all DAC registers are updated.
1 0 1 12-bit DAC data Load input register B; DAC registers are unchanged.
0 0 0 1 1 0 x xxxxxxxx Shut down DAC A (provided PDL = 1).
0 0 0 1 0 1 x xxxxxxxx Update DAC register B from input register B
(start up DAC B with data previously stored in input register B).
0 0 0 0 0 1 x xxxxxxxx Update DAC register A from input register A
(start up DAC A with data previously stored in input register A).
1 1 1 xxxxxxxxxxxx Shut down both DACs (provided PDL = 1).
1 0 0 xxxxxxxxxxxx Update both DAC registers from their respective input registers
(start up both DACs with data previously stored in the input registers).
0 0 0 1 1 1 x xxxxxxxx Shut down DAC B (provided PDL = 1).
0 0 0 0 1 0 x xxxxxxxx UPO goes low (default).
0 0 0 0 1 1 x xxxxxxxx UPO goes high.
0 0 0 1 0 0 1 xxxxxxxx Mode 1, DOUT clocked out on SCLK’s rising edge.
0 0 0 1 0 0 0 xxxxxxxx Mode 0, DOUT clocked out on SCLK’s falling edge (default).
0 0 0 0 0 0 x xxxxxxxx No operation (NOP).
Table 1. Serial-Interface Programming Commands
x = Don’t care
Note: D11, D10, D9, and D8 become control bits when A0, C1, and C0 = 0. S0 is a sub bit, always zero.
SCLK
DIN
CS
SK
SO
I/O
MICROWIRE
PORT
MAX5154
MAX5155
Figure 2. Connections for Microwire
16-BIT SERIAL WORD
S0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
The MAX5154/MAX5155’s digital inputs are double
buffered, which allows any of the following: loading the
input register(s) without updating the DAC register(s),
updating the DAC register(s) from the input register(s),
or updating the input and DAC registers concurrently.
The address and control bits allow the DACs to act
independently.
Send the 16-bit data as one 16-bit word (QSPI) or two
8-bit packets (SPI, Microwire), with CS low during this
period. The address and control bits determine which
register will be updated, and the state of the registers
when exiting shutdown. The 3-bit address/control deter-
mines the following:
•registers to be updated
•clock edge on which data is to be clocked out via
the serial-data output (DOUT)
• state of the user-programmable logic output
• configuration of the device after shutdown.
The general timing diagram of Figure 5 illustrates how
data is acquired. Driving CS low enables the device to
receive data. Otherwise, the interface control circuitry is
disabled. With CS low, data at DIN is clocked into the
register on the rising edge of SCLK. As CS goes high,
data is latched into the input and/or DAC registers
depending on the address and control bits. The maxi-
mum clock frequency guaranteed for proper operation
is 10MHz. Figure 6 depicts a more detailed timing dia-
gram of the serial interface.
MAX5154/MAX5155
Low-Power, Dual, 12-Bit Voltage-Output DACs
with Serial Interface
DIN
SCLK
CS
MOSI
SCK
I/O
SPI/QSPI
PORT
SS
+5V
CPOL = 0, CPHA = 0
MAX5154
MAX5155
Figure 3. Connections for SPI/QSPI
Figure 5. Serial-Interface Timing Diagram
CS
SCLK
DIN
COMMAND
EXECUTED
9
816
1
C1
A0 S0
C0 D11 D10 D9 D8 D5 D4 D3 D2 D1 D0D7 D6
______________________________________________________________________________________ 11
Figure 4. Serial-Data Format
1 Address/2 Control Bits
A0
Address Bits
C1, C0
Control Bits
12 Data Bits
D11.......................D0
MSB...DataBits...LSB
0
S0
SUB
BIT
16 Bits of Serial Data
MSB...................................................................................LSB
MAX5154/MAX5155
Low-Power, Dual, 12-Bit Voltage-Output DACs
with Serial Interface
12 ______________________________________________________________________________________
SCLK
DIN
tCSO tCSS tCL tCH tCP
tCSW
tCS1
tCSH
tDS tDH
CS
Figure 6. Detailed Serial-Interface Timing Diagram
TO OTHER
SERIAL DEVICES
MAX5154
MAX5155
DIN
SCLK
CS
MAX5154
MAX5155 MAX5154
MAX5155
DINDOUT DOUT DOUT
SCLK
CS
DIN
SCLK
CS
TO OTHER
SERIAL DEVICES
MAX5154
MAX5155
DIN
SCLK
CS
MAX5154
MAX5155
DIN
SCLK
CS
MAX5154
MAX5155
DIN
SCLK
CS
DIN
SCLK
CS1
CS2
CS3
Figure 7. Daisy Chaining MAX5154/MAX5155s
Figure 8. Multiple MAX5154/MAX5155s Sharing a Common DIN Line
Serial-Data Output
The serial-data output, DOUT, is the internal shift regis-
ter’s output. DOUT allows for daisy chaining of devices
and data readback. The MAX5154/MAX5155 can be
programmed to shift data out of DOUT on SCLK’s
falling edge (Mode 0) or on the rising edge (Mode 1).
Mode 0 provides a lag of 16 clock cycles, which main-
tains compatibility with SPI/QSPI and Microwire inter-
faces. In Mode 1, the output data lags 15.5 clock
cycles. On power-up, the device defaults to Mode 0.
User-Programmable Logic Output (UPO)
UPO allows an external device to be controlled through
the serial interface (Table 1), thereby reducing the
number of microcontroller I/O pins required. On power-
up, UPO is low.
Power-Down Lockout Input (PPDDLL)
The power-down lockout pin (PDL) disables software
shutdown when low. When in shutdown, transitioning
PDL from high to low wakes up the part with the output
set to the state prior to shutdown. PDL can also be
used to asynchronously wake up the device.
Daisy Chaining Devices
Any number of MAX5154/MAX5155s can be daisy
chained by connecting the DOUT pin of one device to
the DIN pin of the following device in the chain (Figure 7).
Since the MAX5154/MAX5155’s DOUT pin has an inter-
nal active pull-up, the DOUT sink/source capability
determines the time required to discharge/charge a
capacitive load. Refer to the digital output VOH and VOL
specifications in the
Electrical Characteristics
.
Figure 8 shows an alternate method of connecting sev-
eral MAX5154/MAX5155s. In this configuration, the
data bus is common to all devices; data is not shifted
through a daisy chain. More I/O lines are required in
this configuration because a dedicated chip-select
input (CS) is required for each IC.
__________Applications Information
Unipolar Output
Figure 9 shows the MAX5154/MAX5155 configured for
unipolar, rail-to-rail operation with a gain of +2V/V. The
MAX5154 can produce a 0V to 4.096V output with
2.048V reference (Figure 9), while the MAX5155 can
produce a range of 0V to 2.5V with a 1.25V reference.
Table 2 lists the unipolar output codes. An offset to the
output can be achieved by connecting a voltage to
OS_, as shown in Figure 10. By applying VOS_ = -1V,
the output values will range between 1V and (1V +
VREF x 2).
MAX5154/MAX5155
Low-Power, Dual, 12-Bit Voltage-Output DACs
with Serial Interface
Table 2. Unipolar Code Table (Gain = +2)
MAX5154
MAX5155
DAC_
GAIN = +2V/V
REF_
OUT_
OS_
DGNDAGND
+5V/+3V
VDD R
R
Figure 9. Unipolar Output Circuit (Rail-to-Rail)
MAX5154
MAX5155
DAC _
AGND DGND
REF_
OUT_
OS_
VOS
+5V/+3V
VDD R
R
______________________________________________________________________________________ 13
ANALOG OUTPUT
1111 1111 1111 (0)
1000 0000 0001 (0)
DAC CONTENTS
MSB LSB
1000 0000 0000 (0)
0111 1111 1111 (0)
0000 0000 0000 (0) 0V
0000 0000 0001 (0)
+V 4095
4096 2
REF
x
+V 2049
4096
REF
x 2
+V 2048
4096 V
REF REF
= x 2
+V 2047
4096
REF
x 2
+V 1
4096
REF
x 2
Figure 10. Setting OS_ for Output Offset
Note: ( ) are for the sub bit.
MAX5154/MAX5155
Bipolar Output
The MAX5154/MAX5155 can be configured for a bipo-
lar output, as shown in Figure 11. The output voltage is
given by the equation (OS_ = AGND):
VOUT = VREF [((2 x NB) / 4096) - 1]
where NB represents the numeric value of the DAC’s
binary input code. Table 3 shows digital codes and the
corresponding output voltage for Figure 11’s circuit.
Using an AC Reference
In applications where the reference has an AC signal
component, the MAX5154/MAX5155 have multiplying
capabilities within the reference input voltage range
specifications. Figure 12 shows a technique for apply-
ing a sinusoidal input to REF_, where the AC signal is
offset before being applied to the reference input.
Harmonic Distortion and Noise
The total harmonic distortion plus noise (THD+N) is typ-
ically less than -78dB at full scale with a 1Vp-p input
swing at 5kHz. The typical -3dB frequency is 300kHz
for both devices, as shown in the
Typical Operating
Characteristics.
Digital Calibration and
Threshold Selection
Figure 13 shows the MAX5154/MAX5155 in a digital
calibration application. With a bright light value applied
to the photodiode (on), the DAC is digitally ramped until
Low-Power, Dual, 12-Bit Voltage-Output DACs
with Serial Interface
14 ______________________________________________________________________________________
Table 3. Bipolar Code Table
ANALOG OUTPUT
1111 1111 1 111 (0)
1000 0000 0 001 (0)
DAC CONTENTS
MSB LSB
1000 0000 0 000 (0) 0V
0111 1111 1 111 (0)
0000 0000 0 000 (0)
0000 0000 0 001 (0)
+V 2047
2048
REF
+V 1
2048
REF
-V 1
2048
REF
-V 2047
2048
REF
-V 2048
2048 - V
REF REF
=
AGNDDGND
R
R
MAX5154
MAX5155
DAC _
REF_
OS_
OUT_
10k 10k
10k
10k V-
V+
VDD
VOUT
+5V/+3V
Figure 11. Bipolar Output Circuit
DAC_ OUT_
MAX5154
MAX5155
10k
26k
OS_
REF R
R
VDD
DGNDAGND
+5V/
+3V
AC
REFERENCE
INPUT
500mVp-p
MAX495
+5V/+3V
Figure 12. AC Reference Input Circuit
AGND
DIN
µP
DGND
MAX5154
MAX5155
DAC _
REF_ OS_
OUT_
R
R
V-
V+
PHOTODIODE
V+
VDD
VOUT
RPULLDOWN
+5V/+3V
Figure 13. Digital Calibration
Note: ( ) are for the sub bit.
it trips the comparator. The microprocessor (µP) stores
this “high” calibration value. Repeat the process with a
dim light (off) to obtain the dark current calibration.
The µP then programs the DAC to set an output voltage
at the midpoint of the two calibrated values.
Applications include tachometers, motion sensing,
automatic readers, and liquid clarity analysis.
Digital Control of Gain and Offset
The two DACs can be used to control the offset and
gain for curve-fitting nonlinear functions, such as trans-
ducer linearization or analog compression/expansion
applications. The input signal is used as the reference
for the gain-adjust DAC, whose output is summed with
the output from the offset-adjust DAC. The relative
weight of each DAC output is adjusted by R1, R2, R3,
and R4 (Figure 14).
Power-Supply Considerations
On power-up, the input and DAC registers clear (set to
zero code). For rated performance, VREF_ should be at
least 1.4V below VDD. Bypass the power supply with a
4.7µF capacitor in parallel with a 0.1µF capacitor to
AGND. Minimize lead lengths to reduce lead inductance.
Grounding and Layout Considerations
Digital and AC transient signals on AGND can create
noise at the output. Connect AGND to the highest quality
ground available. Use proper grounding techniques,
such as a multilayer board with a low-inductance ground
plane. Carefully lay out the traces between channels to
reduce AC cross-coupling and crosstalk. Wire-wrapped
boards and sockets are not recommended. If noise
becomes an issue, shielding may be required.
MAX5154/MAX5155
Low-Power, Dual, 12-Bit Voltage-Output DACs
with Serial Interface
______________________________________________________________________________________ 15
AGND DGND
MAX5154
MAX5155
DACA
VDD
REFA
VIN
VREF
CS
SCLK
DIN
REFB
R1
R3
R
R
R
R
R4
R2
OUTB
OSB
OUTA
OSA
VOUT
DACB
INPUT
REG A
INPUT
REG B
DAC
REG A
DAC
REG B
– OFFSET
[ ]
VOUT =
=
GAIN
[ ]
2NA
4096
NA IS THE NUMERIC VALUE OF THE INPUT CODE FOR DACA.
NB IS THE NUMERIC VALUE OF THE INPUT CODE FOR DACB.
R2
R1+R2 R4
R3 2NB
4096 R4
R3
(VIN )( )(1+ ) (VREF )( )
[ ] [ ]
SHIFT
REGISTER
Figure 14. Digital Control of Gain and Offset
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
16
____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 1997 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
MAX5154/MAX5155
Low-Power, Dual, 12-Bit Voltage-Output DACs
with Serial Interface
___________________Chip Information
TRANSISTOR COUNT: 3053
SUBSTRATE CONNECTED TO AGND
INL
(LSB)
PIN-PACKAGETEMP. RANGEPART
±1
±1
±1/2
±1
±1/2
16 CERDIP*-55°C to +125°CMAX5154BMJE 16 QSOP-40°C to +85°CMAX5154BEEE 16 QSOP-40°C to +85°CMAX5154AEEE 16 Plastic DIP-40°C to +85°CMAX5154BEPE 16 Plastic DIP-40°C to +85°CMAX5154AEPE
_Ordering Information (continued)
*
Contact factory for availability.
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
AGND VDD
OUTB
OSB
REFB
PDL
UPO
DOUT
DGND
TOP VIEW
MAX5154
MAX5155
DIP/QSOP
OUTA
OSA
CS
REFA
CL
DIN
SCLK
__________________Pin Configuration
QSOP.EPS
________________________________________________________Package Information
±2
±2
±1
±2
±1
±2
±1
16 QSOP0°C to +70°CMAX5155BCEE
±216 Plastic DIP0°C to +70°CMAX5155BCPE ±116 QSOP0°C to +70°CMAX5155ACEE
16 CERDIP*-55°C to +125°CMAX5155BMJE 16 QSOP-40°C to +85°CMAX5155BEEE 16 QSOP-40°C to +85°CMAX5155AEEE 16 Plastic DIP-40°C to +85°CMAX5155BEPE 16 Plastic DIP-40°C to +85°CMAX5155AEPE
16 Plastic DIP0°C to +70°C
MAX5155ACPE