19-1124; Rev 1; 12/96
Low-Power, 13-Bit Voltage-Output DACs
with Serial Interface
______________________________Features
The MAX535/MAX5351 combine a low-power, voltageoutput, 13-bit digital-to-analog converter (DAC) and a
precision output amplifier in an 8-pin µMAX or DIP package. The MAX535 operates from a single +5V supply
and the MAX5351 operates from a single +3.3V supply.
Both devices draw only 280µA of supply current.
The output amplifier’s inverting input is available to the
user, allowing specific gain configurations, remote
sensing, and high output current capability. This makes
the MAX535/MAX5351 ideal for a wide range of applications, including industrial process control. Other features include a software shutdown and power-on reset.
The serial interface is compatible with either SPI™/
QSPI™ or Microwire™. The DAC has a double-buffered
input, organized as an input register followed by a DAC
register. A 16-bit serial word loads data into the input
register. The DAC register can be updated independently or simultaneously with the input register. All logic
inputs are TTL/CMOS-logic compatible and buffered
with Schmitt triggers to allow direct interfacing to optocouplers.
♦ 13-Bit DAC with Configurable Output Amplifier
________________________Applications
♦ +5V Single-Supply Operation (MAX535)
+3.3V Single-Supply Operation (MAX5351)
♦ Low Supply Current: 0.24mA Normal Operation
2µA Shutdown Mode
♦ Available in 8-Pin µMAX
♦ Power-On Reset Clears DAC Output to 0V
♦ SPI/QSPI and Microwire Compatible
♦ Schmitt-Trigger Digital Inputs for Direct
Optocoupler Interface
_________________Ordering Information
PIN-PACKAGE
INL
(LSB)
0°C to +70°C
8 Plastic DIP
±1/2
0°C to +70°C
8 Plastic DIP
±1
±1/2
PART
TEMP. RANGE
MAX535ACPA
MAX535BCPA
MAX535ACUA
0°C to +70°C
8 µMAX†
Industrial Process Controls
MAX535BCUA
0°C to +70°C
8 µMAX
±1
Automatic Test Equipment
MAX535BC/D
0°C to +70°C
Dice*
±1
Ordering Information continued at end of data sheet.
†Contact factory for availability.
*Dice are tested at TA = +25°C, DC parameters only.
Digital Offset and Gain Adjustment
Motion Control
Remote Industrial Controls
Microprocessor-Controlled Systems
____________________Functional Diagram
VDD
GND
REF
_______________________Pin Configuration
TOP VIEW
FB
DAC
REGISTER
OUT
DAC
CONTROL
CS 2
INPUT
REGISTER
CS
DIN
SCLK
OUT 1
DIN 3
MAX535
MAX5351
SCLK 4
16-BIT
SHIFT
REGISTER
MAX535
MAX5351
8
VDD
7
GND
6
REF
5
FB
DIP/µMAX
SPI and QSPI are registered trademarks of Motorola, Inc. Microwire is a registered trademark of National Semiconductor Corp.
________________________________________________________________ Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800
MAX535/MAX5351
__________________General Description
MAX535/MAX5351
Low-Power, 13-Bit Voltage-Output DACs
with Serial Interface
ABSOLUTE MAXIMUM RATINGS
VDD to GND .................................................................-0.3V, +6V
REF, OUT, FB to GND ................................-0.3V to (VDD + 0.3V)
Digital Inputs to GND ...............................................-0.3V to +6V
Continuous Current into Any Pin.......................................±20mA
Continuous Power Dissipation (TA = +70°C)
Plastic DIP (derate 6.90mW/°C above +70°C) .................552mW
µMAX (derate 4.00mW/°C above +70°C) ......................330mW
CERDIP (derate 8.00mW/°C above +70°C) ...................640mW
Operating Temperature Ranges
MAX535_C_A/MAX5351_C_A...............................0°C to +70°C
MAX535_E_A/MAX5351_E_A ............................-40°C to +85°C
MAX535BMJA/MAX5351BMJA .......................-55°C to +125°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10sec) .............................+300°C
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.
ELECTRICAL CHARACTERISTICS: MAX535
(VDD = +5V ±10%, REF = 2.5V, GND = 0V, RL = 5kΩ, CL = 100pF, TA = TMIN to TMAX, unless otherwise noted. Typical values are at
TA = +25°C. Output buffer connected in unity-gain configuration (Figure 8).)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
STATIC PERFORMANCE—ANALOG SECTION
Resolution
Integral Nonlinearity
(Note 1)
N
INL
Differential Nonlinearity
DNL
Offset Error
VOS
Offset-Error Tempco
Gain Error (Note 1)
13
MAX535A
±0.5
MAX535B
±1.0
MAX535MJA
±2.0
Guaranteed monotonic
±0.3
TCVOS
6
GE
-0.5
Gain-Error Tempco
Power-Supply Rejection Ratio
Bits
±1.0
LSB
±8
mV
ppm/°C
±6
1
PSRR
4.5V ≤ VDD ≤ 5.5V
LSB
LSB
ppm/°C
600
µV/V
REFERENCE INPUT
Reference Input Range
VREF
Reference Input Resistance
RREF
0
Code dependent, minimum at code 1555 hex
14
VDD - 1.4
V
20
kΩ
MULTIPLYING-MODE PERFORMANCE
Reference -3dB Bandwidth
VREF = 0.67Vp-p
650
kHz
Reference Feedthrough
Input code = all 0s, VREF = 3.6Vp-p at 1kHz
-84
dB
VREF = 1Vp-p at 25kHz, code = full scale
77
dB
Signal-to-Noise Plus
Distortion Ratio
SINAD
DIGITAL INPUTS
2
Input High Voltage
VIH
Input Low Voltage
VIL
Input Leakage Current
IIN
Input Capacitance
CIN
2.4
VIN = 0V or VDD
V
0.001
8
_______________________________________________________________________________________
0.8
V
±0.5
µA
pF
Low-Power, 13-Bit Voltage-Output DACs
with Serial Interface
(VDD = +5V ±10%, REF = 2.5V, GND = 0V, RL = 5kΩ, CL = 100pF, TA = TMIN to TMAX, unless otherwise noted. Typical values are at
TA = +25°C. Output buffer connected in unity-gain configuration (Figure 8).)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DIGITAL INPUTS
DYNAMIC
PERFORMANCE
Voltage Output Slew Rate
SR
Output Settling Time
To ±1/2LSB, VSTEP = 2.5V
Output Voltage Swing
Rail-to-rail (Note 2)
0.6
V/µs
16
µs
0 to VDD
Current into FB
0.001
Time to Valid Operation
on Start-Up
CS = VDD, DIN = 100kHz
Digital Feedthrough
V
±0.1
µA
20
µs
5
nV-s
POWER SUPPLIES
Supply Voltage
VDD
Supply Current
IDD
Supply Current in Shutdown
4.5
(Note 3)
5.5
V
0.4
mA
4
20
µA
0.001
±0.5
µA
0.28
(Note 3)
Reference Current in Shutdown
TIMING CHARACTERISTICS
SCLK Clock Period
tCP
100
ns
SCLK Pulse Width High
tCH
40
ns
SCLK Pulse Width Low
tCL
40
ns
CS Fall to SCLK Rise Setup Time
tCSS
40
ns
SCLK Rise to CS Rise Hold Time
tCSH
0
ns
DIN Setup Time
tDS
40
ns
DIN Hold Time
tDH
0
ns
SCLK Rise to CS Fall Delay
tCS0
40
ns
CS Rise to SCLK Rise Hold Time
tCS1
40
ns
CS Pulse Width High
tCSW
100
ns
Note 1: Guaranteed from code 22 to code 8191 in unity-gain configuration.
Note 2: Accuracy is better than 1LSB for VOUT = 8mV to VDD - 100mV, guaranteed by a power-supply rejection test at the
end points.
Note 3: RL = ∞, digital inputs at GND or VDD.
_______________________________________________________________________________________
3
MAX535/MAX5351
ELECTRICAL CHARACTERISTICS: MAX535 (continued)
MAX535/MAX5351
Low-Power, 13-Bit Voltage-Output DACs
with Serial Interface
ELECTRICAL CHARACTERISTICS: MAX5351
(VDD = +3.15V to +3.6V, REF = 1.25V, GND = 0V, RL = 5kΩ, CL = 100pF, TA = TMIN to TMAX, unless otherwise noted. Typical values
are at TA = +25°C. Output buffer connected in unity-gain configuration (Figure 8).)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
STATIC PERFORMANCE—ANALOG SECTION
Resolution
N
Integral Nonlinearity
(Note 4)
INL
Differential Nonlinearity
DNL
Offset Error
VOS
13
Bits
MAX5351A
±1
MAX5351B
±2
MAX5351MJA
Offset-Error Tempco
Gain Error (Note 4)
±4
Guaranteed monotonic
±0.3
TCVOS
6
GE
-0.5
Gain-Error Tempco
Power-Supply Rejection Ratio
LSB
±1.0
LSB
±8
mV
ppm/°C
±6
1
LSB
ppm/°C
PSRR
600
µV/V
REFERENCE INPUT
Reference Input Range
VREF
Reference Input Resistance
RREF
0
Code dependent, minimum at code 1555 hex
14
VDD - 1.4
V
20
kΩ
MULTIPLYING-MODE PERFORMANCE (VDD = +3.3V)
Reference -3dB Bandwidth
VREF = 0.67Vp-p
650
kHz
Reference Feedthrough
Input code = all 0s, VREF = 1.9Vp-p at 1kHz
-84
dB
VREF = 1Vp-p at 25kHz, code = full scale
72
dB
Signal-to-Noise Plus
Distortion Ratio
SINAD
DIGITAL INPUTS
Input High Voltage
VIH
Input Low Voltage
VIL
Input Leakage Current
IIN
Input Capacitance
CIN
2.4
VIN = 0V or VDD
V
0.001
0.6
V
±0.5
µA
8
pF
0.6
V/µs
16
µs
DYNAMIC PERFORMANCE
Voltage Output Slew Rate
SR
Output Settling Time
To ±1/2LSB, VSTEP = 1.25V
Output Voltage Swing
Rail-to-rail (Note 5)
0 to VDD
Current into FB
0.001
Time to Valid Operation
on Start-Up
CS = VDD, DIN = 100kHz
Digital Feedthrough
V
±0.1
µA
20
µs
5
nV-s
POWER SUPPLIES
Supply Voltage
VDD
Supply Current
IDD
Supply Current in Shutdown
Reference Current in Shutdown
4
3.15
(Note 6)
(Note 6)
3.6
V
0.4
mA
1.6
10
µA
0.001
±0.5
µA
0.24
_______________________________________________________________________________________
Low-Power, 13-Bit Voltage-Output DACs
with Serial Interface
(VDD = +3.15V to +3.6V, REF = 1.25V, GND = 0V, RL = 5kΩ, CL = 100pF, TA = TMIN to TMAX, unless otherwise noted. Typical values
are at TA = +25°C. Output buffer connected in unity-gain configuration (Figure 8).)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
TIMING CHARACTERISTICS
SCLK Clock Period
tCP
100
ns
SCLK Pulse Width High
tCH
40
ns
SCLK Pulse Width Low
tCL
40
ns
CS Fall to SCLK Rise Setup Time
tCSS
40
ns
SCLK Rise to CS Rise Hold Time
tCSH
0
ns
DIN Setup Time
tDS
40
ns
DIN Hold Time
tDH
0
ns
SCLK Rise to CS Fall Delay
tCS0
40
ns
CS Rise to SCLK Rise Hold Time
tCS1
40
ns
CS Pulse Width High
tCSW
100
ns
Note 4: Guaranteed from code 44 to code 8191 in unity-gain configuration.
Note 5: Accuracy is better than 1LSB for VOUT = 8mV to VDD - 150mV, guaranteed by a power-supply rejection test at the
end points.
Note 6: RL = ∞, digital inputs at GND or VDD.
_______________________________________________________________________________________
5
MAX535/MAX5351
ELECTRICAL CHARACTERISTICS: MAX5351 (continued)
__________________________________________Typical Operating Characteristics
(MAX535 only, VDD = +5V, RL = 5kΩ, CL = 100pF, TA = +25°C, unless otherwise noted.)
MAX535
360
-0.1
-0.2
-0.3
SUPPLY CURRENT (µA)
RELATIVE OUTPUT (dB)
0
-8
-12
-16
-0.4
340
320
300
280
260
240
220
200
-60
-20
0
1M
1.5M
2M
2.5M
3M
6
5
4
3
300
250
200
20
60
100
-70
-75
-80
-85
-90
0
4.0
140
4.4
4.8
5.2
5.6
100
10
1
6.0
TEMPERATURE (°C)
SUPPLY VOLTAGE (V)
FREQUENCY (kHz)
OUTPUT FFT PLOT
FULL-SCALE OUTPUT
vs. LOAD
REFERENCE FEEDTHROUGH
AT 1kHz
2.499
-40
-60
-80
0
2.498
REFERENCE INPUT SIGNAL
SIGNAL AMPLITUDE (dB)
-20
2.500
MAX535-08
VREF = 3.6Vp-p
CODE = FULL SCALE
fIN = 1kHz
MAX535-07
0
FULL-SCALE OUTPUT (V)
-20
-65
150
50
1
140
-60
350
100
2
VREF = 2.5VDC + 1Vp-p SINE
CODE = FULL SCALE
-55
400
THD + NOISE (dB)
7
100
-50
MAX535-05
450
SUPPLY CURRENT (µA)
8
60
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
500
MAX535-04
9
20
TEMPERATURE (°C)
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
10
-20
FREQUENCY (Hz)
POWER-DOWN SUPPLY CURRENT
vs. TEMPERATURE
0
-60
500k
MAX535-06
0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0 4.4
REFERENCE VOLTAGE (V)
2.497
2.496
2.495
2.494
2.493
-20
MAX535-09a/09b
-0.5
POWER-DOWN SUPPLY CURRENT (µA)
RL = ∞
380
-4
0.1
MAX535-03
0.2
400
MAX535-02
0
MAX535-01
0.3
INL (LSB)
SUPPLY CURRENT
vs. TEMPERATURE
REFERENCE VOLTAGE INPUT
FREQUENCY RESPONSE
INTEGRAL NONLINEARITY
vs. REFERENCE VOLTAGE
SIGNAL AMPLITUDE (dB)
MAX535/MAX5351
Low-Power, 13-Bit Voltage-Output DACs
with Serial Interface
-40
-60
OUTPUT FEEDTHROUGH
-80
2.492
2.491
-100
0.5
2.490
1.6
2.7
3.8
FREQUENCY (kHz)
6
4.9
6.0
0.01k
0.1k
1k
10k 100k
LOAD (Ω)
1M
10M
-100
0.5
1.6
2.7
3.8
FREQUENCY (kHz)
_______________________________________________________________________________________
4.9
6.0
Low-Power, 13-Bit Voltage-Output DACs
with Serial Interface
MAX535 (continued)
DIGITAL FEEDTHROUGH (fSCLK = 100kHz)
MAX535-11
MAX535-10
MAJOR-CARRY TRANSITION
CS
5V/div
SCLK,
2V/div
OUT,
AC COUPLED
100mV/div
OUT,
AC COUPLED
10mV/div
CODE = 4096
10µs/div
2µs/div
CS = 5V
MAX535-12
DYNAMIC RESPONSE
OUT
1V/div
GND
10µs/div
GAIN = 2, SWITCHING FROM CODE 0 TO 8040
_______________________________________________________________________________________
7
MAX535/MAX5351
____________________________Typical Operating Characteristics (continued)
(MAX535 only, VDD = +5V, RL = 5kΩ, CL = 100pF, TA = +25°C, unless otherwise noted.)
____________________________Typical Operating Characteristics (continued)
(MAX5351 only, VDD = +3.3V, RL = 5kΩ, CL = 100pF, TA = +25°C, unless otherwise noted.)
MAX5351
-0.2
-0.4
-0.6
SUPPLY CURRENT (µA)
RELATIVE OUTPUT (dB)
0
-8
-12
320
300
280
260
240
-16
-0.8
220
0.8
1.2
1.6
2.0
REFERENCE VOLTAGE (V)
2.4
500k
2.5M
3.0
2.5
2.0
1.5
MAX535-17
400
350
300
250
200
60
100
140
3.0
3.1
3.2
-65
-70
3.3
3.4
3.5
3.7
3.6
3.8
FREQUENCY (kHz)
FULL-SCALE OUTPUT
vs. LOAD
OUTPUT FFT PLOT
-60
-80
0
1.24930
1.24928
REFERENCE INPUT SIGNAL
SIGNAL AMPLITUDE (dB)
-40
REFERENCE FEEDTHROUGH
AT 1kHz
MAX535-20
1.24932
MAX535-19
VREF = 1.9Vp-p
CODE = FULL SCALE
fIN = 1kHz
FULL-SCALE OUTPUT (V)
0
100
10
1
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
-20
-60
-80
100
20
140
-75
150
-20
100
VREF = 1VDC + 0.5Vp-p SINE
CODE = FULL SCALE
-55
1.0
0.5
60
-50
THD + NOISE (dB)
3.5
20
TOTAL HARMONIC DISTORTION
PLUS NOISE vs. FREQUENCY
450
SUPPLY CURRENT (µA)
4.0
0
-60
-20
TEMPERATURE (°C)
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX535-16
4.5
2M
1.5M
FREQUENCY (Hz)
POWER-DOWN SUPPLY CURRENT
vs. TEMPERATURE
5.0
1M
1.24926
1.24924
1.24922
1.24920
1.24918
MAX535-21
0.4
200
-60
MAX535-18
-20
100k
-1.0
POWER-DOWN SUPPLY CURRENT (µA)
RL = ∞
340
-4
0.2
MAX535-15
360
MAX535-14
0.4
INL (LSB)
0
MAX535-13
0.6
SUPPLY CURRENT
vs. TEMPERATURE
REFERENCE VOLTAGE INPUT
FREQUENCY RESPONSE
INTEGRAL NONLINEARITY
vs. REFERENCE VOLTAGE
SIGNAL AMPLITUDE (dB)
MAX535/MAX5351
Low-Power, 13-Bit Voltage-Output DACs
with Serial Interface
-20
-40
-60
OUTPUT FEEDTHROUGH
-80
1.24916
-100
0.5
1.24914
1.6
2.7
3.8
FREQUENCY (kHz)
8
4.9
6.0
100
1k
10k
100k
LOAD (Ω)
1M
10M
-100
0.5
1.2
1.9
2.6
FREQUENCY (kHz)
_______________________________________________________________________________________
3.3
4.0
Low-Power, 13-Bit Voltage-Output DACs
with Serial Interface
MAX535/MAX5351
_____________________Pin Description
FB
PIN
NAME
FUNCTION
1
OUT
2
CS
Chip-Select Input. Active low.
3
DIN
Serial-Data Input
4
SCLK
Serial-Clock Input
5
FB
6
REF
Reference Voltage Input
7
GND
Ground
8
VDD
Positive Power Supply
R
DAC Output Voltage
2R
DAC Output Amplifier Feedback
2R
D0
R
2R
D10
OUT
R
2R
2R
D11
D12
REF
AGND
SHOWN FOR ALL 1s ON DAC
Figure 1. Simplified DAC Circuit Diagram
_______________Detailed Description
The MAX535/MAX5351 contain a 13-bit, voltage-output
digital-to-analog converter (DAC) that is easily
addressed using a simple 3-wire serial interface. It
includes a 16-bit shift register, and has a doubledbuffered input composed of an input register and a
DAC register (see Functional Diagram). In addition to
the voltage output, the amplifier’s negative input is
available to the user.
The DAC is an inverted R-2R ladder network that converts a 13-bit digital input into an equivalent analog output voltage in proportion to the applied reference
voltage input. Figure 1 shows a simplified circuit diagram of the DAC.
code of 0000 hex. Because the input impedance at the
reference pin is code dependent, load regulation of the
reference source is important.
The REF reference input has a 14kΩ guaranteed minimum input impedance. A voltage reference with a load
regulation of 6ppm/mA, such as the MAX873, would
typically deviate by 0.0062LSB (0.009LSB worst case)
when driving the MAX535 reference input at 2.5V.
In shutdown mode, the MAX535/MAX5351’s REF input
enters a high-impedance state with a typical input leakage current of 0.001µA.
The reference input capacitance is also code dependent and typically ranges from 15pF (with an input
code of all 0s) to 50pF (with an input code of all 1s).
Reference Inputs
Output Amplifier
The reference input accepts positive DC and AC signals. The voltage at the reference input sets the fullscale output voltage for the DAC. The reference input
voltage range is 0V to (VDD - 1.4V). The output voltage
(VOUT) is represented by a digitally programmable voltage source as:
The MAX535/MAX5351’s DAC output is internally
buffered by a precision amplifier with a typical slew rate
of 0.6V/µs. Access to the output amplifier’s inverting
input provides the user greater flexibility in output gain
setting/signal conditioning (see the Applications
Information section).
With a full-scale transition at the MAX535/MAX5351 output, the typical settling time to ±1/2LSB is 16µs when
loaded with 5kΩ in parallel with 100pF (loads less than
2kΩ degrade performance).
The MAX535 output amplifier’s output dynamic responses and settling performances are shown in the
Typical Operating Characteristics.
VOUT = (VREF x NB / 8192 ) x Gain
where NB is the numeric value of the DAC’s binary
input code (0 to 8191), VREF is the reference voltage,
and Gain is the externally set voltage gain.
The impedance at the reference input is code dependent, ranging from a low value of 14kΩ when the DAC
has an input code of 1555 hex, to a high value exceeding several giga ohms (leakage currents) with an input
_______________________________________________________________________________________
9
MAX535/MAX5351
Low-Power, 13-Bit Voltage-Output DACs
with Serial Interface
Shutdown Mode
The MAX535/MAX5351 feature a software-programmable
shutdown that reduces supply current to a typical value
of 4µA. Writing 111XXXXXXXXXXXXX as the input-control
word puts the MAX535/MAX5351 in shutdown mode
(Table 1).
In shutdown mode, the MAX535/MAX5351 output amplifier and the reference input enter a high-impedance
state. The serial interface remains active. Data in the
input registers is retained in shutdown, allowing the
MAX535/MAX5351 to recall the output state prior to
entering shutdown. Exit shutdown mode by either recalling the previous configuration or by updating the DAC
with new data. When powering up the device or bringing
it out of shutdown, allow 20µs for the output to stabilize.
Serial-Interface Configurations
The MAX535/MAX5351’s 3-wire serial interface is compatible with both Microwire™ (Figure 2) and
SPI™/QSPI™ (Figure 3). The serial input word consists
of three control bits followed by 13 data bits (MSB first),
as shown in Figure 4. The 3-bit control code determines
the MAX535/MAX5351’s response outlined in Table 1.
The MAX535/MAX5351’s digital inputs are double
buffered. Depending on the command issued through
the serial interface, the input register can be loaded
without affecting the DAC register, the DAC register
can be loaded directly, or the DAC register can be
updated from the input register (Table 1).
10
SK
DIN
SO
CS
I/O
MAX535
MAX5351
MICROWIRE
PORT
Figure 2. Connections for Microwire
+5V
SS
DIN
MAX535
MAX5351
Serial-Interface Description
The MAX535/MAX5351 require 16 bits of serial data.
Table 1 lists the serial-interface programming commands. For certain commands, the 13 data bits are
“don’t cares.” Data is sent MSB first and can be sent in
two 8-bit packets or one 16-bit word (CS must remain
low until 16 bits are transferred). The serial data is composed of three control bits (C2, C1, C0), followed by the
13 data bits D12...D0 (Figure 4). The 3-bit control code
determines:
• The register to be updated
• The configuration when exiting shutdown
Figure 5 shows the serial-interface timing requirements.
The chip-select pin (CS) must be low to enable the DAC’s
serial interface. When CS is high, the interface control circuitry is disabled. CS must go low at least tCSS before the
rising serial clock (SCLK) edge to properly clock in the
first bit. When CS is low, data is clocked into the internal
shift register via the serial-data input pin (DIN) on SCLK’s
rising edge. The maximum guaranteed clock frequency is
10MHz. Data is latched into the MAX535/MAX5351
input/DAC register on CS’s rising edge.
SCLK
MOSI
SCLK
SCK
CS
SPI/QSPI
PORT
I/O
CPOL = 0, CPHA = 0
Figure 3. Connections for SPI/QSPI
MSB ..................................................................................LSB
16 Bits of Serial Data
Control
Bits
C2
C1
Data Bits
MSB.............................................LSB
C0
D12................................................D0
3 Control
Bits
13 Data Bits
Figure 4. Serial-Data Format
______________________________________________________________________________________
Low-Power, 13-Bit Voltage-Output DACs
with Serial Interface
16-BIT SERIAL WORD
C1
C0
D12............................D0
MSB
LSB
FUNCTION
C2
X
0
0
13 bits of data
Load input register; DAC register immediately updated (also exit shutdown).
X
0
1
13 bits of data
Load input register; DAC register unchanged.
X
1
0
XXXXXXXXXXXXX
Update DAC register from input register (also exit shutdown; recall previous state).
1
1
1
XXXXXXXXXXXXX
Shutdown
0
1
1
XXXXXXXXXXXXX
No operation (NOP)
“X” = Don’t care
CS
COMMAND
EXECUTED
SCLK
1
DIN
8
C1
C2
C0 D12 D11 D10
D9
D8
9
D7
16
D6
D5
D4
D3
D2
D1
D0
Figure 5. Serial-Interface Timing Diagram
tCSW
CS
tCSO
tCSS
tCL
tCH
tCP
tCSH
tCS1
SCLK
tDS
tDH
DIN
Figure 6. Detailed Serial-Interface Timing Diagram
______________________________________________________________________________________
11
MAX535/MAX5351
Table 1. Serial-Interface Programming Commands
MAX535/MAX5351
Low-Power, 13-Bit Voltage-Output DACs
with Serial Interface
DIN
SCLK
CS1
CS2
TO OTHER
SERIAL DEVICES
CS3
CS
CS
MAX535
MAX5351
CS
MAX535
MAX5351
MAX535
MAX5351
SCLK
SCLK
SCLK
DIN
DIN
DIN
Figure 7. Multiple MAX535/MAX5351s Sharing Common DIN and SCLK Lines
Figure 7 shows a method of connecting several
MAX535/MAX5351s. In this configuration, the clock and
the data bus are common to all devices and separate
chip-select lines are used for each IC.
__________Applications Information
Table 2. Unipolar Code Table
DAC CONTENTS
MSB
LSB
11111
1111
1111
8191
+VREF
8192
10000
0000
0001
4097
+VREF
8192
10000
0000
0000
4096
+ VREF
+VREF
=
2
8192
01111
1111
1111
4095
+VREF
8192
00000
0000
0001
1
+VREF
8192
00000
0000
0000
0V
Unipolar Output
For a unipolar output, the output voltage and the reference input have the same polarity. Figure 8 shows the
MAX535/MAX5351 unipolar output circuit, which is also
the typical operating circuit. Table 2 lists the unipolar
output codes.
For rail-to-rail output, see Figure 9. This circuit shows
the MAX535/MAX5351 with the output amplifier configured with a closed-loop gain of +2 to provide 0V to 5V
full-scale range when a 2.5V reference is used. When
using the MAX5351 with a 1.25V reference, this circuit
provides a 0V to 2.5V full-scale range.
Bipolar Output
The MAX535/MAX5351 output can be configured for
bipolar operation using Figure 10’s circuit.
VOUT = VREF [(2NB / 8192) - 1]
where NB is the numeric value of the DAC’s binary input
code. Table 3 shows digital codes (offset binary) and
the corresponding output voltage for Figure 10’s circuit.
12
ANALOG OUTPUT
Using an AC Reference
In applications where the reference has AC-signal components, the MAX535/MAX5351 have multiplying capability within the reference input range specifications.
Figure 11 shows a technique for applying a sine-wave
signal to the reference input where the AC signal is offset before being applied to REF. The reference voltage
must never be more negative than GND.
______________________________________________________________________________________
Low-Power, 13-Bit Voltage-Output DACs
with Serial Interface
DAC CONTENTS
MSB
LSB
ANALOG OUTPUT
11111
1111
1111
4095
+VREF
4096
10000
0000
0001
1
+VREF
4096
10000
0000
0000
0V
01111
1111
1111
1
-VREF
4096
00000
0000
0001
4095
-VREF
4096
00000
0000
0000
4096
-VREF
= - VREF
4096
MAX535
MAX5351
The MAX535’s total harmonic distortion plus noise (THD
+ N) is typically less than -77dB (full-scale code), and
the MAX5351’s THD + N is typically less than -72dB
(full-scale code), given a 1Vp-p signal swing and input
frequencies up to 25kHz. The typical -3dB frequency is
650kHz for both devices, as shown in the Typical
Operating Characteristics graphs.
Digitally Programmable Current Source
The circuit of Figure 12 places an NPN transistor
(2N3904 or similar) within the op-amp feedback loop to
implement a digitally programmable, unidirectional current source. This circuit can be used to drive 4–20mA
current loops, which are commonly used in industrialcontrol applications. The output current is calculated
with the following equation:
IOUT = (VREF / R) x (NB / 8192)
where NB is the numeric value of the DAC’s binary
input code and R is the sense resistor shown in
Figure 12.
MAX535
MAX5351
+5V/+3.3V
REF
+5V/+3.3V
REF
VDD
VDD
FB
10k
FB
10k
DAC
OUT
GND
Figure 8. Unipolar Output Circuit
DAC
OUT
GND
Figure 9. Unipolar Rail-to-Rail Output Circuit
______________________________________________________________________________________
13
MAX535/MAX5351
Table 3. Bipolar Code Table
MAX535/MAX5351
Low-Power, 13-Bit Voltage-Output DACs
with Serial Interface
+5V/
+3.3V
R1
R2
+5V/+3.3V
REF
AC
REFERENCE
INPUT
+5V/+3.3V
VDD
26k
MAX495
+V
FB
500mVp-p
10k
VDD
REF
VOUT
DAC
OUT
DAC
V-
MAX535
MAX5351
GND
OUT
R1 = R2 = 10kΩ ±0.1%
MAX535
MAX5351 GND
Figure 10. Bipolar Output Circuit
Figure 11. AC Reference Input Circuit
Grounding and Layout Considerations
+5V/
+3.3V
REF
VDD
VL
DAC
MAX535
MAX5351
IOUT
OUT
2N3904
Digital or AC transient signals on GND can create noise
at the analog output. Tie GND to the highest-quality
ground available.
Good printed circuit board ground layout minimizes
crosstalk between the DAC output, reference input, and
digital input. Reduce crosstalk by keeping analog lines
away from digital lines. Wire-wrapped boards are not
recommended.
FB
GND
R
Figure 12. Digitally Programmable Current Source
Power-Supply Considerations
On power-up, the input and DAC registers are cleared
(set to zero code).
For rated MAX535/MAX5351 performance, REF should
be at least 1.4V below VDD. Bypass VDD with a 4.7µF
capacitor in parallel with a 0.1µF capacitor to GND.
Use short lead lengths and place the bypass capacitors as close to the supply pins as possible.
14
______________________________________________________________________________________
Low-Power, 13-Bit Voltage-Output DACs
with Serial Interface
PART
INL
(LSB)
TEMP. RANGE
PIN-PACKAGE
MAX535AEPA
MAX535BEPA
-40°C to +85°C
-40°C to +85°C
8 Plastic DIP
8 Plastic DIP
±1/2
±1
MAX535AEUA
MAX535BEUA
MAX535BMJA
MAX5351ACPA
MAX5351BCPA
-40°C to +85°C
-40°C to +85°C
-55°C to +125°C
0°C to +70°C
0°C to +70°C
8 µMAX†
8 µMAX
8 CERDIP**
8 Plastic DIP
8 Plastic DIP
±1/2
±1
±2
±1
±2
MAX5351ACUA
MAX5351BCUA
MAX5351BC/D
MAX5351AEPA
MAX5351BEPA
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
-40°C to +85°C
8 µMAX†
8 µMAX
Dice*
8 Plastic DIP
8 Plastic DIP
±1
±2
±2
±1
±2
MAX5351AEUA
MAX5351BEUA
MAX5351BMJA
-40°C to +85°C 8 µMAX†
-40°C to +85°C 8 µMAX
-55°C to +125°C 8 CERDIP**
___________________Chip Information
TRANSISTOR COUNT: 1677
±1
±2
±4
† Contact factory for availability.
* Dice are tested at +25°C, DC parameters only.
** Contact factory for availability and processing to MIL-STD-883.
________________________________________________________Package Information
D
E
DIM
E1
A
A1
A2
A3
B
B1
C
D1
E
E1
e
eA
eB
L
A3
A A2
L A1
0° - 15°
C
e
B1
B
eA
eB
D1
Plastic DIP
PLASTIC
DUAL-IN-LINE
PACKAGE
(0.300 in.)
INCHES
MAX
MIN
0.200
–
–
0.015
0.175
0.125
0.080
0.055
0.022
0.016
0.065
0.045
0.012
0.008
0.080
0.005
0.325
0.300
0.310
0.240
–
0.100
–
0.300
0.400
–
0.150
0.115
PKG. DIM PINS
P
P
P
P
P
N
D
D
D
D
D
D
8
14
16
18
20
24
INCHES
MIN
MAX
0.348 0.390
0.735 0.765
0.745 0.765
0.885 0.915
1.015 1.045
1.14 1.265
MILLIMETERS
MIN
MAX
–
5.08
0.38
–
3.18
4.45
1.40
2.03
0.41
0.56
1.14
1.65
0.20
0.30
0.13
2.03
7.62
8.26
6.10
7.87
2.54
–
7.62
–
–
10.16
2.92
3.81
MILLIMETERS
MIN
MAX
8.84
9.91
18.67 19.43
18.92 19.43
22.48 23.24
25.78 26.54
28.96 32.13
21-0043A
______________________________________________________________________________________
15
MAX535/MAX5351
_Ordering Information (continued)
MAX535/MAX5351
Low-Power, 13-Bit Voltage-Output DACs
with Serial Interface
___________________________________________Package Information (continued)
DIM
C
α
A
0.101mm
0.004 in
e
B
A1
L
A
A1
B
C
D
E
e
H
L
α
INCHES
MAX
MIN
0.044
0.036
0.008
0.004
0.014
0.010
0.007
0.005
0.120
0.116
0.120
0.116
0.0256
0.198
0.188
0.026
0.016
6°
0°
MILLIMETERS
MIN
MAX
0.91
1.11
0.10
0.20
0.25
0.36
0.13
0.18
2.95
3.05
2.95
3.05
0.65
4.78
5.03
0.41
0.66
0°
6°
21-0036D
E
H
8-PIN µMAX
MICROMAX SMALL-OUTLINE
PACKAGE
D
DIM
E1
E
D
A
0°-15°
Q
L
L1
e
C
B1
B
S1
S
CERDIP
CERAMIC DUAL-IN-LINE
PACKAGE
(0.300 in.)
A
B
B1
C
E
E1
e
L
L1
Q
S
S1
INCHES
MIN
MAX
–
0.200
0.014
0.023
0.038
0.065
0.008
0.015
0.220
0.310
0.290
0.320
0.100
0.125
0.200
0.150
–
0.015
0.070
–
0.098
0.005
–
DIM PINS
D
D
D
D
D
D
8
14
16
18
20
24
MILLIMETERS
MIN
MAX
–
5.08
0.36
0.58
0.97
1.65
0.20
0.38
5.59
7.87
7.37
8.13
2.54
3.18
5.08
3.81
–
0.38
1.78
–
2.49
0.13
–
INCHES
MILLIMETERS
MIN
MAX MIN MAX
–
0.405
–
10.29
–
0.785
–
19.94
–
0.840
–
21.34
–
0.960
–
24.38
–
1.060
–
26.92
–
1.280
–
32.51
21-0045A
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
© 1996 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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