General Description
The MAX5487/MAX5488/MAX5489 dual, linear-taper,
digital potentiometers function as mechanical potentiometers
with a simple 3-wire SPI™-compatible digital interface
that programs the wipers to any one of 256 tap positions.
These digital potentiometers feature a nonvolatile memory
(EEPROM) to return the wipers to their previously stored
positions upon power-up.
The MAX5487 has an end-to-end resistance of 10kΩ,
while the MAX5488 and MAX5489 have resistances of
50kΩ and 100kΩ, respectively. These devices have a low
35ppm/°C end-to-end temperature coefficient, and operate
from a single +2.7V to +5.25V supply.
The MAX5487/MAX5488/MAX5489 are available in
16-pin 3mm x 3mm x 0.8mm TQFN or 14-pin TSSOP
packages. Each device is guaranteed over the extended
-40°C to +85°C temperature range.
Applications
●LCD Screen Adjustment
●Audio Volume Control
●Mechanical Potentiometer Replacement
●Low-Drift Programmable Filters
● Low-Drift Programmable-Gain Ampliers
Benets and Features
●Wiper Position Stored in Nonvolatile Memory
(EEPROM) and Recalled Upon Power-Up or
Recalled by an Interface Command
●3mm x 3mm x 0.8mm, 16-Pin TQFN or 14-Pin
TSSOP Packages
●±1 LSB INL, ±0.5 LSB DNL (Voltage-Divider Mode)
●256 Tap Positions
●35ppm/°C End-to-End Resistance Temperature
Coefficient
●5ppm/°C Ratiometric Temperature Coefficient
●10kΩ, 50kΩ, and 100kΩ End-to-End Resistance
Values
●SPI-Compatible Serial Interface
●Reliability
• 200,000 Wiper Store Cycles
• 50-Year Wiper Data Retention
●+2.7V to +5.25V Single-Supply Operation
SPI is a trademark of Motorola, Inc.
19-3478; Rev 4; 4/10
Functional Diagram
MAX5487
MAX5488
MAX5489
POR
8-BIT
LATCH
16-BIT
NV RAM
SCLK
DIN
CS
DECODER
8
8
256
DECODER
256
HA
WA
LA
HB
WB
LB
VDD
GND
SPI
INTERFACE
8-BIT
LATCH
MAX5487/MAX5488/
MAX5489
Dual, 256-Tap, Nonvolatile, SPI-Interface,
Linear-Taper Digital Potentiometers
EVALUATION KIT AVAILABLE
VDD to GND .........................................................-0.3V to +6.0V
All Other Pins
to GND .............-0.3V to the lower of (VDD + 0.3V) and +6.0V
Maximum Continuous Current into H_, W_, and L_
MAX5487 ..................................................................... ±5.0mA
MAX5488 ..................................................................... ±1.3mA
MAX5489 ..................................................................... ±0.6mA
Continuous Power Dissipation (TA = +70°C)
16-Pin TQFN (derate 17.5mW/°C above +70°C) ......1398mW
14-Pin TSSOP (derate 9.1mW/°C above +70°C) ........ 727mW
Operating Temperature Range ........................... -40°C to +85°C
Junction Temperature ...................................................... +150°C
Storage Temperature Range ............................ -60°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Soldering Temperature (reflow) ....................................... +260°C
(VDD = +2.7V to +5.25V, VH = VDD, VL = GND, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VDD = +5.0V,
TA = +25°C, unless otherwise noted.) (Note 1)
DC Electrical Characteristics
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.
Absolute Maximum Ratings
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
DC PERFORMANCE (Voltage-Divider Mode, Figure 1)
Resolution N 256 Taps
Integral Nonlinearity INL (Note 2) ±1 LSB
Differential Nonlinearity DNL (Note 2) ±0.5 LSB
Dual-Code Matching Register A = register B 2 LSB
End-to-End Resistor Tempco TCR35 ppm/°C
Ratiometric Resistor Tempco 5 ppm/°C
Full-Scale Error
MAX5487 3.5 6
LSBMAX5488 -0.6 +1.2
MAX5489 -0.3 +1.2
Zero-Scale Error
MAX5487 3.5 6
LSBMAX5488 -0.6 1.5
MAX5489 0.3 1
DC PERFORMANCE (Variable-Resistor Mode, Figure 1)
Resolution 256 Taps
Integral Nonlinearity (Note 3) VDD = 5.0V ±1.5 LSB
VDD = 3.0V ±3
Differential Nonlinearity (Note 3) VDD = 5.0V ±1 LSB
VDD = 3.0V ±1
DC PERFORMANCE (Resistor Characteristics)
Wiper Resistance (Note 4) RW
VDD = 5.0V 200 350
Ω
VDD = 3.0V 325 675
Wiper Capacitance CW50 pF
End-to-End Resistance RHL
MAX5487 7.5 10 12.5
kΩ
MAX5488 37.5 50 62.5
MAX5489 75 100 125
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MAX5487/MAX5488/
MAX5489
Dual, 256-Tap, Nonvolatile, SPI-Interface,
Linear-Taper Digital Potentiometers
(VDD = +2.7V to +5.25V, VH = VDD, VL = GND, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VDD = +5.0V,
TA = +25°C, unless otherwise noted.) (Note 1)
DC Electrical Characteristics (continued)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
DIGITAL INPUTS
Input High Voltage (Note 5) VIH
VDD = 3.6V to 5.25V 2.4
V
VDD = 2.7V to 3.6V 0.7 x
VDD
Input Low Voltage VIL VDD = 2.7V to 5.25V (Note 5) 0.8 V
Input Leakage Current IIN ±1.0 µA
Input Capacitance CIN 5.0 pF
AC PERFORMANCE
Crosstalk fH_ = 1kHz, L_ = GND, measurement at W_
(Note 6) -90 dB
-3dB Bandwidth BW Wiper at midscale
CW_ = 10pF
MAX5487 350
kHzMAX5488 90
MAX5489 45
Total Harmonic Distortion THD VH_ = 1VRMS at 1kHz, L_ = GND,
measurement at W_ 0.02 %
TIMING CHARACTERISTICS (Analog)
Wiper-Settling Time tSCode 0 to 127
(Note 7)
MAX5487 0.5
µsMAX5488 0.75
MAX5489 1.5
TIMING CHARACTERISTICS (Digital, Figure 2, Note 8)
SCLK Frequency 5 MHz
SCLK Clock Period tCP 200 ns
SCLK Pulse-Width High tCH 80 ns
SCLK Pulse-Width Low tCL 80 ns
CS Fall to SCLK Rise Setup tCSS 80 ns
SCLK Rise to CS Rise Hold tCSH 0 ns
DIN to SCLK Setup tDS 50 ns
DIN Hold after SCLK tDH 0 ns
SCLK Rise to CS Fall Delay tCS0 20 ns
CS Rise to SCLK Rise Hold tCS1 80 ns
CS Pulse-Width High tCSW 200 ns
Write NV Register Busy Time tBUSY 12 ms
Read NV Register Access Time tACC 1 µs
Write Wiper Register to Output Delay tWO 1 µs
NONVOLATILE MEMORY RELIABILITY
Data Retention TA = +85°C 50 Years
Endurance TA = +25°C 200,000 Stores
TA = +85°C 50,000
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MAX5487/MAX5488/
MAX5489
Dual, 256-Tap, Nonvolatile, SPI-Interface,
Linear-Taper Digital Potentiometers
Note 1: All devices are production tested at TA = +85°C and are guaranteed by design and characterization for -40°C < TA <
+85°C.
Note 2: DNL and INL are measured with the potentiometer configured as a voltage-divider with H_ = VDD and L_ = 0. The wiper
terminal is unloaded and measured with an ideal voltmeter.
Note 3: DNL and INL are measured with the potentiometer configured as a variable resistor. H_ is unconnected and L_ = 0. For
VDD = +5V, the wiper terminal is driven with a source current of 400µA for the 10kΩ configuration, 80µA for the 50kΩ
configuration, and 40µA for the 100kΩ configuration. For VDD = +3V, the wiper terminal is driven with a source current of
200µA for the 10kΩ configuration, 40µA for the 50kΩ configuration, and 20µA for the 100kΩ configuration.
Note 4: The wiper resistance is the worst value measured by injecting the currents given in Note 3 into W_ with L_ = GND. RW =
(VW - VH) / IW.
Note 5: The device draws higher supply current when the digital inputs are driven with voltages between (VDD - 0.5V) and (GND +
0.5V). See Supply Current vs. Digital Input Voltage in the Typical Operating Characteristics section.
Note 6: Wiper at midscale with a 10pF load.
Note 7: Wiper-settling time is the worst-case 0-to-50% rise time, measured between tap 0 and tap 127. H_ = VDD, L_ = GND, and
the wiper terminal is unloaded and measured with a 10pF oscilloscope probe (see Tap-to-Tap Switching Transient in the
Typical Operating Characteristics section).
Note 8: Digital timing is guaranteed by design and characterization, and is not production tested.
(VDD = +2.7V to +5.25V, VH = VDD, VL = GND, TA = -40°C to +85°C, unless otherwise noted. Typical values are at VDD = +5.0V,
TA = +25°C, unless otherwise noted.) (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
POWER SUPPLIES
Power-Supply Voltage VDD 2.70 5.25 V
Supply Current IDD During write cycle only, digital inputs = VDD
or GND 400 µA
Standby Current Digital inputs = VDD or GND, TA = +25°C 0.5 1 µA
DC Electrical Characteristics (continued)
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MAX5487/MAX5488/
MAX5489
Dual, 256-Tap, Nonvolatile, SPI-Interface,
Linear-Taper Digital Potentiometers
(VDD = +5.0V, TA = +25°C, unless otherwise noted.)
Typical Operating Characteristics
FREQUENCY (kHz)
GAIN (dB)
MIDSCALE FREQUENCY RESPONSE
(MAX5487)
0
-2
-4
-6
-8
-10
-12
-14
-16
-18
-20
0.1 1 10 100 1000
MAX5487-89 toc08
CW = 10pF
CW_ = 50pF
WIPER TRANSIENT AT POWER-ON
MAX5487-89 toc07
2.0µs/div
WIPER
2.0V/div
VH_ = VDD
VDD
2.0V/div
TAP-TO-TAP SWITCHING TRANSIENT
(MAX5489)
MAX5487-89 toc06
1.0µs/div
WIPER
20mV/div
VH_ = 5.0V
CS
2.0V/div
TAP-TO-TAP SWITCHING TRANSIENT
(MAX5488)
MAX5487-89 toc05
1.0µs/div
WIPER
20mV/div
VH_ = 5.0V
CS
2.0V/div
1µs/div
TAP-TO-TAP SWITCHING TRANSIENT
(MAX5487)
CS
2.0V/div
WIPER
20mV/div
MAX5487-89 toc04
VH_ = 5.0V
0
50
150
100
200
250
0 64 9632 128 160 192 224 256
WIPER RESISTANCE
vs. TAP POSITION
MAX5487-89 toc03
TAP POSITION
WIPER RESISTANCE ()
SUPPLY CURRENT
vs. DIGITAL INPUT VOLTAGE
MAX5487-89 toc02
DIGITAL INPUT VOLTAGE (V)
SUPPLY CURRENT (µA)
4321
1
10
100
1000
10,000
0
0 5
VCC = 5V
VCC = 3V
0.1
0
-40 -20 0 20 40 60 80
0.5
0.4
0.3
0.2
0.6
TEMPERATURE (°C)
SUPPLY CURRENT (A)
SUPPLY CURRENT
vs. TEMPERATURE
MAX5487-89 toc01
VDD = 3V
VDD = 5V
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MAX5487/MAX5488/
MAX5489
Dual, 256-Tap, Nonvolatile, SPI-Interface,
Linear-Taper Digital Potentiometers
(VDD = +5.0V, TA = +25°C, unless otherwise noted.)
Typical Operating Characteristics (continued)
VOLTAGE-DIVIDER INL
vs. TAP POSITION (MAX5488)
MAx5487-89 toc16
TAP POSITION
INL (LSB)
22419232 64 96 128 160
-0.6
-0.8
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1.0
-1.0
0 256
VOLTAGE-DIVIDER DNL
vs. TAP POSITION (MAX5488)
MAx5487-89 toc15
TAP POSITION
DNL (LSB)
22419232 64 96 128 160
-0.15
-0.10
-0.05
0
0.05
0.10
0.15
0.20
-0.20
0 256
0.6
0.2
0.4
0.2
0
0.6
0.4
0.8
1.2
1.0
1.4
0 64 9632 128 160 192 224 256
VOLTAGE-DIVIDER INL
vs. TAP POSITION (MAX5487)
MAX5487-89 toc14
TAP POSITION
INL (LSB)
-0.20
-0.10
-0.15
0
-0.05
0.05
0.10
0.15
0.20
0 64 9632 128 160 192 224 256
VOLTAGE-DIVIDER DNL
vs. TAP POSITION (MAX5487)
MAX5487-89 toc13
TAP POSITION
DNL (LSB)
VARIABLE-RESISTOR INL
vs. TAP POSITION (MAX5488)
MAx5487-89 toc12
TAP POSITION
INL (LSB)
22419232 64 96 128 160
-0.6
-0.8
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1.0
-1.0
0 256
VARIABLE-RESISTOR DNL
vs. TAP POSITION (MAX5488)
MAx5487-89 toc11
TAP POSITION
DNL (LSB)
22419232 64 96 128 160
-0.15
-0.10
-0.05
0
0.05
0.10
0.15
0.20
-0.20
0 256
MIDSCALE FREQUENCY RESPONSE
(MAX5489)
MAX5487-89 toc10
FREQUENCY (kHz)
GAIN (dB)
100101
-45
-40
-35
-30
-25
-20
-15
-10
-5
0
-50
0.1 1000
CW_ = 10pF
CW_ = 50pF
MIDSCALE FREQUENCY RESPONSE
(MAX5488)
MAX5487-89 toc09
FREQUENCY (kHz)
GAIN (dB)
100101
-45
-40
-35
-30
-25
-20
-15
-10
-5
0
-50
0.1 1000
CW_ = 10pF
CW_ = 50pF
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MAX5487/MAX5488/
MAX5489
Dual, 256-Tap, Nonvolatile, SPI-Interface,
Linear-Taper Digital Potentiometers
(VDD = +5.0V, TA = +25°C, unless otherwise noted.)
Typical Operating Characteristics (continued)
-0.010
-0.004
-0.006
-0.008
-0.002
0
0.002
0.004
0.006
0.008
0.010
-40 10-15 35 60 85
END-TO-END RESISTANCE CHANGE
vs. TEMPERATURE (MAX5489)
MAX5487-89 toc24
TEMPERATURE (°C)
RESISTANCE CHANGE (%)
-0.010
-0.004
-0.006
-0.008
-0.002
0
0.002
0.004
0.006
0.008
0.010
-40 10-15 35 60 85
END-TO-END RESISTANCE CHANGE
vs. TEMPERATURE (MAX5488)
MAX5487-89 toc23
TEMPERATURE (°C)
RESISTANCE CHANGE (%)
-0.010
-0.004
-0.006
-0.008
-0.002
0
0.002
0.004
0.006
0.008
0.010
-40 10-15 35 60 85
END-TO-END RESISTANCE CHANGE
vs. TEMPERATURE (MAX5487)
MAX5487-89 toc22
TEMPERATURE (°C)
RESISTANCE CHANGE (%)
-100
-80
-90
-60
-70
-40
-50
-30
CROSSTALK
vs. FREQUENCY
MAX5487-89 toc21
FREQUENCY (kHz)
CROSSTALK (dB)
0.1 1 10 100 1000
MAX5487
MAX5488
MAX5489
CW_ = 10pF
VOLTAGE-DIVIDER INL
vs. TAP POSITION (MAX5489)
MAx5487-89 toc20
TAP POSITION
INL (LSB)
22419232 64 96 128 160
-0.6
-0.8
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1.0
-1.0
0 256
VOLTAGE-DIVIDER DNL
vs. TAP POSITION (MAX5489)
MAx5487-89 toc19
TAP POSITION
DNL (LSB)
22419232 64 96 128 160
-0.15
-0.10
-0.05
0
0.05
0.10
0.15
0.20
-0.20
0 256
VARIABLE-RESISTOR INL
vs. TAP POSITION (MAX5489)
MAx5487-89 toc18
TAP POSITION
INL (LSB)
22419232 64 96 128 160
-0.6
-0.8
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1.0
-1.0
0 256
VARIABLE-RESISTOR DNL
vs. TAP POSITION (MAX5489)
MAx5487-89 toc17
TAP POSITION
DNL (LSB)
22419232 64 96 128 160
-0.15
-0.10
-0.05
0
0.05
0.10
0.15
0.20
-0.20
0 256
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MAX5487/MAX5488/
MAX5489
Dual, 256-Tap, Nonvolatile, SPI-Interface,
Linear-Taper Digital Potentiometers
Pin Congurations
I.C.
15
16
14
13
5
*EP
*EXPOSED PAD.
6
7
DIN
CS
8
VDD
LB
N.C.
HB
1
+
3
WA
4
12 10 9
HA
I.C.
GND
N.C.
N.C.
MAX5487
MAX5488
MAX5489
SCLK WB
2
11
LA
TQFN
3mm x 3mm
TOP VIEW
14
13
12
11
10
9
8
1
2
3
4
5
6
7
VDD
SCLK
DIN
CS
HB
LA
WA
HA
TOP VIEW
MAX5487
MAX5488
MAX5489 N.C.
N.C.
GNDN.C.
LB
WB
TSSOP
+
Pin Description
PIN NAME FUNCTION
TQFN TSSOP
1 14 VDD Power Supply. Bypass VDD to GND with a 0.1µF capacitor as close to the device as possible.
2 13 SCLK Serial-Interface Clock Input
3 12 DIN Serial-Interface Data Input
4 11 CS Active-Low Chip-Select Digital Input
5, 6, 9 7, 9, 10 N.C. No Connection. Not internally connected.
7 8 GND Ground
8, 16 — I.C. Internally connected to EP. Leave unconnected.
10 6 LB Low Terminal of Resistor B. The voltage at L can be greater than or less than the voltage at H.
Current can flow into or out of L.
11 5 WB Wiper Terminal of Resistor B
12 4 HB High Terminal of Resistor B. The voltage at H can be greater than or less than the voltage at L.
Current can flow into or out of H.
13 3 LA Low Terminal of Resistor A. The voltage at L can be greater than or less than the voltage at H.
Current can flow into or out of L.
14 2 WA Wiper Terminal of Resistor A
15 1 HA High Terminal of Resistor A. The voltage at H can be greater than or less than the voltage at L.
Current can flow into or out of H.
— — EP Exposed Pad (TQFN only). Internally connected to pins 8 and 16. Leave unconnected.
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MAX5487/MAX5488/
MAX5489
Dual, 256-Tap, Nonvolatile, SPI-Interface,
Linear-Taper Digital Potentiometers
Detailed Description
The MAX5487/MAX5488/MAX5489 contain two resistor
arrays, with 255 resistive elements each. The MAX5487
has an end-to-end resistance of 10kΩ, while the MAX5488
and MAX5489 have resistances of 50kΩ and 100kΩ,
respectively. These devices allow access to the high, low,
and wiper terminals on both potentiometers for a standard
voltage-divider configuration. Connect the wiper to the
high terminal, and connect the low terminal to ground, to
make the device a variable resistor (see Figure 1).
A simple 3-wire serial interface programs either wiper
directly to any of the 256 tap points. The nonvolatile memory
stores the wiper position prior to power-down and recalls
the wiper to the same point upon power-up or by using an
interface command (see Table 1). The nonvolatile memory
is guaranteed for 200,000 wiper store cycles and 50 years
for wiper data retention.
SPI Digital Interface
These devices use a 3-wire SPI-compatible serial
data interface (Figure 2 and Figure 3). This write-only
interface contains three inputs: chip-select (CS), data
clock (SCLK), and data in (DIN). Drive CS low to enable
the serial interface and clock data synchronously into the
shift register on each SCLK rising edge.
The WRITE commands (C1, C0 = 00 or 01) require 16
clock cycles to clock in the command, address, and data
(Figure 3a). The COPY commands (C1, C0 = 10, 11) can
use either eight clock cycles to transfer only command
and address bits (Figure 3b) or 16 clock cycles, with the
device disregarding 8 data bits (Figure 3a).
After loading data into the shift register, drive CS high
to latch the data into the appropriate potentiometer
control register and disable the serial interface. Keep
CS low during the entire serial data stream to avoid
corruption of the data.
Digital-Interface Format
The data format consists of three elements: command
bits, address bits, and data bits (see Table 1 and
Figure 3). The command bits (C1 and C0) indicate
the action to be taken such as changing or storing the
wiper position. The address bits (A1 and A0) specify
which potentiometer the command affects and the 8
data bits (D7 to D0) specify the wiper position.
Table 1. Register Map
CLOCK EDGE 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
— — C1 C0 — — A1 A0 D7 D6 D5 D4 D3 D2 D1 D0
Write Wiper Register A 0 0 0 0 0 0 0 1 D7 D6 D5 D4 D3 D2 D1 D0
Write Wiper Register B 0 0 0 0 0 0 1 0 D7 D6 D5 D4 D3 D2 D1 D0
Write NV Register A 0 0 0 1 0 0 0 1 D7 D6 D5 D4 D3 D2 D1 D0
Write NV Register B 0 0 0 1 0 0 1 0 D7 D6 D5 D4 D3 D2 D1 D0
Copy Wiper Register A to NV
Register A 0 0 1 0 0 0 0 1 — — — — — — — —
Copy Wiper Register B to NV
Register B 0 0 1 0 0 0 1 0 — — — — — — — —
Copy Both Wiper Registers to
NV Registers 0 0 1 0 0 0 1 1 — — — — — — — —
Copy NV Register A to Wiper
Register A 0 0 1 1 0 0 0 1 — — — — — — — —
Copy NV Register B to Wiper
Register B 0 0 1 1 0 0 1 0 — — — — — — — —
Copy Both NV Registers to
Wiper Registers 0 0 1 1 0 0 1 1 — — — — — — — —
Figure 1. Voltage-Divider/Variable-Resistor Configurations
H
L
W
VOLTAGE-DIVIDER
CONFIGURATION
VARIABLE-RESISTOR
CONFIGURATION
H
L
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MAX5487/MAX5488/
MAX5489
Dual, 256-Tap, Nonvolatile, SPI-Interface,
Linear-Taper Digital Potentiometers
Write-Wiper Register (Command 00)
Data written to the write-wiper registers (C1, C0 = 00)
controls the wiper positions. The 8 data bits (D7 to D0)
indicate the position of the wiper. For example, if DIN =
0000 0000, the wiper moves to the position closest to L_.
If DIN = 1111 1111, the wiper moves closest to H_.
This command writes data to the volatile RAM, leaving
the NV registers unchanged. When the device powers up,
the data stored in the NV registers transfers to the volatile
wiper register, moving the wiper to the stored position.
Write-NV Register (Command 01)
This command (C1, C0 = 01) stores the position of
the wipers to the NV registers for use at power-up.
Alternatively, the “copy wiper register to NV register”
command can be used to store the position of the wipers
to the NV registers. Writing to the NV registers does not
affect the position of the wipers.
Copy Wiper Register to NV Register (Command 10)
This command (C1, C0 = 10) stores the current position
of the wiper to the NV register, for use at power-up.
This command may affect one potentiometer at a time,
Figure 2. Timing Diagram
CS
tCSO
tCSS tCL tCH
tDH
tDS
tCP tCSH
tCSW
tCS1
SCLK
DIN
Figure 3. Digital-Interface Format
16151413121110987654321
SCLK
C1 C0 D7 D6 D5 D4 D3 D2 D1 D0A1 A0
87654321
C1 C0 A1 A0
DIN
SCLK
CS
B) 8-BIT COMMAND WORD
A) 16-BIT COMMAND/DATA WORD
CS
DIN
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MAX5487/MAX5488/
MAX5489
Dual, 256-Tap, Nonvolatile, SPI-Interface,
Linear-Taper Digital Potentiometers
or both simultaneously, depending on the state of A1 and
A0. Alternatively, the “write NV register” command can be
used to store the current position of the wiper to the NV
register.
Copy NV Register to Wiper Register (Command 11)
This command (C1, C0 = 11) restores the wiper position
to the previously stored position in the NV register. This
command may affect one potentiometer at a time, or both
simultaneously, depending on the state of A1 and A0.
Nonvolatile Memory
The internal EEPROM consists of a nonvolatile register
that retains the last stored value prior to power-down.
The nonvolatile register is programmed to midscale at the
factory. The nonvolatile memory is guaranteed for 200,000
wiper write cycles and 50 years for wiper data retention.
Power-Up
Upon power-up, these devices load the data stored in
the nonvolatile wiper register into the volatile memory
register, updating the wiper position with the data stored
in the nonvolatile wiper register. This initialization period
takes 5µs.
Standby
The MAX5487/MAX5488/MAX5489 feature a low-
power standby mode. When the device is not being
programmed, it enters into standby mode and supply
current drops to 0.5µA (typ).
Applications Information
The MAX5487/MAX5488/MAX5489 are ideal for circuits
requiring digitally controlled adjustable resistance, such
as LCD contrast control (where voltage biasing adjusts
the display contrast), or for programmable filters with
adjustable gain and/or cutoff frequency.
Positive LCD Bias Control
Figure 4 and Figure 5 show an application where the
devices provide an adjustable, positive LCD-bias voltage.
The op amp provides buffering and gain to the resistor-
divider network made by the potentiometer (Figure 4) or
by a fixed resistor and a variable resistor (Figure 5).
Programmable Filter
Figure 6 shows the MAX5487/MAX5488/MAX5489 in a
1st-order programmable-filter application. Adjust the gain
of the filter with R2, and set the cutoff frequency with R3.
Use the following equations to calculate the gain (A) and
the -3dB cutoff frequency (fC)
Figure 6. Programmable Filter
1/2 MAX5487
1/2 MAX5488
1/2 MAX5489
1/2 MAX5487
1/2 MAX5488
1/2 MAX5489
VIN
R2
HB
WB
LB
R1
VOUT
R3
HA
WA
LA
CMAX410
V+
V-
R2, R3 = RHL x D / 256
WHERE RHL = END-TO-END RESISTANCE
AND D = DECIMAL VALUE OF WIPER CODE
Figure 5. Positive LCD-Bias Control Using a Variable Resistor
VOUT
30V
5V
W_
H_
L_
MAX5487
MAX5488
MAX5489
MAX480
Figure 4. Positive LCD-Bias Control Using a Voltage-Divider
VOUT
30V
5V
W_
H_
L_
MAX5487
MAX5488
MAX5489
MAX480
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│
11
MAX5487/MAX5488/
MAX5489
Dual, 256-Tap, Nonvolatile, SPI-Interface,
Linear-Taper Digital Potentiometers
1
2
R
A1
R
= +
C
3
1
f
2R C
=
π× ×
Adjustable Voltage Reference
Figure 7 shows the devices used as the feedback
resistors in multiple adjustable voltage-reference
applications. Independently adjust the output voltages of
the MAX6160s from 1.23V to VIN - 0.2V by changing the
wiper positions of the MAX5487/MAX5488/MAX5489.
Offset Voltage and Gain Adjustment
Connect the high and low terminals of one potentiometer
of a MAX5487/MAX5488/MAX5489 to the NULL inputs of
a MAX410, and connect the wiper to the op amp’s positive
supply to nullify the offset voltage over the operating
temperature range. Install the other potentiometer in the
feedback path to adjust the gain of the MAX410 (see
Figure 8).
Figure 7. Adjustable Voltage Reference
MAX6160
IN
5V
OUT
ADJ
GND
HA
LA
WA
VOUT1 IN OUT
ADJ
GND
HB
LB
WB
VOUT2
1/2 MAX5487
1/2 MAX5488
1/2 MAX5489
MAX6160
1/2 MAX5487
1/2 MAX5488
1/2 MAX5489
FOR THE MAX5487
VOUT_ = 1.23V x 10kΩ
R
FOR THE MAX5488
VOUT_ = 1.23V x 50kΩ
R
FOR THE MAX5489
VOUT_ = 1.23V x 100kΩ
R
R2 = RHL x D / 256
WHERE RHL = END-TO-END RESISTANCE
AND D = DECIMAL VALUE OF WIPER CODE
R R
Figure 8. Offset Voltage and Gain Adjustment
3
2
5V
7
4
1
6
8
MAX410
HA LA
WA
R2
R1
HB
LB
WB
1/2 MAX5487/MAX5488/MAX5489
1/2 MAX5487/MAX5488/MAX5489
R2 = RHL x D / 256
WHERE RHL = END-TO-END RESISTANCE
AND = D DECIMAL VALUE OF WIPER CODE
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12
MAX5487/MAX5488/
MAX5489
Dual, 256-Tap, Nonvolatile, SPI-Interface,
Linear-Taper Digital Potentiometers
*EP = Exposed pad.
+Denotes a lead(Pb)-free/RoHS-compliant package.
/V denotes an automotive qualified part.
Ordering Information
Package Information
For the latest package outline information and land patterns
(footprints), go to www.maximintegrated.com/packages. Note
that a “+”, “#”, or “-” in the package code indicates RoHS status
only. Package drawings may show a different suffix character, but
the drawing pertains to the package regardless of RoHS status.
PACKAGE
TYPE
PACKAGE
CODE
OUTLINE NO.
LAND
PATTERN NO.
16 TQFN-EP T1633F+3 21-0036 90-0033
14 TSSOP U14+1 21-0066 90-0113
PART TEMP RANGE PIN-PACKAGE END-TO-END
RESISTANCE (kΩ)TOP MARK
MAX5487ETE+ -40°C to +85°C 16 TQFN-EP* 10 ABR
MAX5487EUD+ -40°C to +85°C 14 TSSOP 10 —
MAX5488ETE+ -40°C to +85°C 16 TQFN-EP* 50 ABS
MAX5488EUD+ -40°C to +85°C 14 TSSOP 50 —
MAX5489ETE+ -40°C to +85°C 16 TQFN-EP* 100 ABT
MAX5489EUD+ -40°C to +85°C 14 TSSOP 100 —
MAX5489ETE/V+ -40°C to +85°C 16 TQFN-EP* 100 AIE
Chip Information
PROCESS: BiCMOS
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│
13
MAX5487/MAX5488/
MAX5489
Dual, 256-Tap, Nonvolatile, SPI-Interface,
Linear-Taper Digital Potentiometers
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
3 1/07 — 1, 8, 12, 15
4 4/10
Updated Ordering Information (added lead-free packaging and automotive
qualified part, released TSSOP package), and updated Absolute Maximum
Ratings
1, 2, 12
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated reserves the right to change the circuitry and specications without notice at any time. The parametric values (min and max limits)
shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. © 2010 Maxim Integrated Products, Inc.
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14
MAX5487/MAX5488/
MAX5489
Dual, 256-Tap, Nonvolatile, SPI-Interface,
Linear-Taper Digital Potentiometers
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.