General Description
The MAX5432–MAX5435 nonvolatile, linear-taper, digi-
tal potentiometers perform the function of a mechanical
potentiometer, but replace the mechanics with a simple
2-wire serial interface. Each device performs the same
function as a discrete potentiometer or a variable resis-
tor and has 32 tap points.
The MAX5432–MAX5435 feature an internal, nonvolatile,
electrically erasable programmable read-only memory
(EEPROM) that returns the wiper to its previously stored
position at power-up. The fast-mode I2C-compatible
serial interface allows communication at data rates up to
400kbps, minimizing board space and reducing inter-
connection complexity. Each device is available with
multiple factory-preset I2C addresses (see the Ordering
Information/Selector Guide).
Use the MAX5432–MAX5435 in applications requiring
digitally controlled resistors. Two resistance values are
available (50kΩand 100kΩ) in a voltage-divider or vari-
able resistor configuration. The nominal resistor temper-
ature coefficient is 35ppm/°C end-to-end, and only
5ppm/°C ratiometric, making the devices ideal for
applications requiring a low-temperature-coefficient
variable resistor such as low-drift, programmable-gain
amplifier circuit configurations.
The MAX5432/MAX5433 are available in a 3mm x 3mm
8-pin TDFN package and the MAX5434/MAX5435 are
available in a 6-pin thin SOT23 package. The MAX5432–
MAX5435 are specified over the extended (-40°C to
+85°C) temperature range.
Applications
Mechanical Potentiometer Replacement
Low-Drift Programmable-Gain Amplifiers
Volume Control
Liquid-Crystal Display (LCD) Screen Adjustment
Features
♦Tiny 3mm x 3mm 8-Pin TDFN and 6-Pin Thin
SOT23 Packages
♦Power-On Recall of Wiper Position from
Nonvolatile Memory
♦35ppm/°C End-to-End Resistance Temperature
Coefficient
♦5ppm/°C Ratiometric Temperature Coefficient
♦50kΩ/100kΩResistor Values
♦Fast 400kbps I2C-Compatible Serial Interface
♦500nA (typ) Static Supply Current
♦+2.7V to +5.25V Single-Supply Operation
♦32 Tap Positions
♦±0.15 LSB INL (typ), ±0.15 LSB DNL (typ)
MAX5432–MAX5435
32-Tap, Nonvolatile, I2C, Linear, Digital
Potentiometers
________________________________________________________________ Maxim Integrated Products 1
Ordering Information/Selector Guide
19-3511; Rev 3; 11/07
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
EVALUATION KIT
AVAILABLE
PART PIN-PACKAGE TOP MARK I2C ADDRESS R (kΩΩ
ΩΩ) PKG CODE
MAX5432LETA+ 8 TDFN-EP* ANG 010100A0** 50 T833-1
MAX5432META+ 8 TDFN-EP* ANI 010110A0** 50 T833-1
MAX5433LETA+ 8 TDFN-EP* ANF 010100A0** 100 T833-1
MAX5433META+ 8 TDFN-EP* ANH 010110A0** 100 T833-1
MAX5434LEZT+T 6 Thin SOT23-6 AABX 0101000 50 Z6-1
*EP = Exposed pad.
**A0represents the logic state of input A0 of the device in the TDFN package.
+Denotes a lead-free package.
T = Tape and reel.
Note: All devices are specified over the -40°C to +85°C operating temperature range.
TDFN
+
TOP VIEW
GND
SDASCL
16L
5W
VDD
SOT23
2
34
MAX5434
MAX5435
A0
VDD
SCL
1
2
8
7
W
LSDA
GND
H
3
4
6
5
MAX5432
MAX5433
+
Pin Configurations
Ordering Information/Selector Guide continued at end of data sheet.
MAX5432–MAX5435
32-Tap, Nonvolatile, I2C, Linear, Digital
Potentiometers
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
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 GND...........................................................-0.3V to +6.0V
SDA, SCL to GND..................................................-0.3V to +6.0V
A0, H, L, and W to GND .............................-0.3V to (VDD + 0.3V)
Maximum Continuous Current into H, L, and W
MAX5432/MAX5434.....................................................±1.3mA
MAX5433/MAX5435.....................................................±0.6mA
Input/Output Latchup Immunity........................................±50mA
Continuous Power Dissipation (TA= +70°C)
6-Pin Thin SOT23 (derate 9.1mW/°C above +70°C)....727mW
8-Pin TDFN (derate 18.2mW/°C above +70°C) ......1454.5mW
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
ELECTRICAL CHARACTERISTICS
(VDD = +2.7V to +5.25V, VH= VDD, VL= GND, TA= -40°C to +85°C, unless otherwise noted. Typical values are at VDD = +5V, TA=
+25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN TYP MAX
UNITS
DC PERFORMANCE
Resolution 32
Taps
MAX5432/MAX5434
37.5
50
62.5
End-to-End Resistance RH-L MAX5433/MAX5435 75
100 125
kΩ
End-to-End Resistance
Temperature Coefficient TCR35
ppm/°C
Ratiometric Resistance
Temperature Coefficient 5
ppm/°C
VDD = 5V
±0.15 ±0.5
Variable resistor (Note 2) VDD = 3V
±0.15 ±0.5
VDD = 5V
±0.15 ±0.5
Integral Nonlinearity INL
Voltage-divider,
MAX5432/MAX5433 (Note 3)
VDD = 3V
±0.15 ±0.5
LSB
VDD = 5V
±0.15 ±0.5
Variable resistor (Note 2) VDD = 3V
±0.15 ±0.5
VDD = 5V
±0.15 ±0.5
Differential Nonlinearity DNL
Voltage-divider,
MAX5432/MAX5433 (Note 3)
VDD = 3V
±0.15 ±0.5
LSB
MAX5432, 50kΩ
-0.5
Full-Scale Error (Note 4) MAX5433, 100kΩ
-0.5
LSB
MAX5432, 50kΩ
+0.5
Zero-Scale Error (Note 5) MAX5433, 100kΩ
+0.5
LSB
Wiper Resistance RWMAX5432/MAX5433 (Note 6)
610 1200
Ω
DIGITAL INPUTS
Input High Voltage VIH (Note 7) 0.7 x
VDD
V
Input Low Voltage VIL (Note 7) 0.3 x
VDD
V
Input Leakage Current ILEAK ±1 µA
Input Capacitance 5pF
MAX5432–MAX5435
32-Tap, Nonvolatile, I2C, Linear, Digital
Potentiometers
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(VDD = +2.7V to +5.25V, VH= VDD, VL= GND, TA= -40°C to +85°C, unless otherwise noted. Typical values are at VDD = +5V, TA=
+25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN TYP MAX
UNITS
DYNAMIC CHARACTERISTICS
MAX5432/MAX5434
500
-3dB Bandwidth (Note 8) MAX5433/MAX5435
250
kHz
MAX5432/MAX5434 0.5
Wiper Settling Time (Note 9) MAX5433/MAX5435 1.0 µs
NONVOLATILE MEMORY RELIABILITY
Data Retention TA = +85°C 50
Years
TA = +25°C
200,000
Endurance TA = +85°C
50,000
Stores
POWER SUPPLY
Power-Supply Voltage VDD
2.70 5.25
V
Standby Current IDD Digital inputs = VDD or GND, TA = +25°C 0.5 2 µA
Programming Current During nonvolatile write; digital inputs =
VDD or GND (Note 10) 200
900
µA
Note 1: All devices are production tested at TA= +25°C and are guaranteed by design and characterization for -40°C < TA< +85°C.
TIMING CHARACTERISTICS
(VDD = +2.7V to +5.25V, VH= VDD, VL= GND, TA= -40°C to +85°C, unless otherwise noted. Typical values are at VDD = +5V, TA=
+25°C.) (Figures 1 and 2) (Note 11)
PARAMETER
SYMBOL
CONDITIONS
MIN TYP MAX
UNITS
SCL Clock Frequency fSCL
400
kHz
Setup Time for START Condition
tSU-STA 0.6 µs
Hold Time for START Condition
tHD-STA
0.6 µs
CLK High Time tHIGH 0.6 µs
CLK Low Time tLOW 1.3 µs
Data Setup Time
tSU-DAT 100
ns
Data Hold Time
tHD-DAT
0 0.9 µs
SDA, SCL Rise Time tR
300
ns
SDA, SCL Fall Time tF
300
ns
Setup Time for STOP Condition
tSU-STO
0.6 µs
Bus Free Time Between STOP
and START Condition tBUF 1.3 µs
Pulse Width of Spike Suppressed
tSP 50 ns
Capacitive Load for Each Bus
Line CB(Note 12)
400
pF
Nonvolatile Store Time Idle time required after a nonvolatile
memory write (Note 13) 12 ms
MAX5432–MAX5435
32-Tap, Nonvolatile, I2C, Linear, Digital
Potentiometers
4 _______________________________________________________________________________________
TIMING CHARACTERISTICS (continued)
(VDD = +2.7V to +5.25V, VH= VDD, VL= GND, TA= -40°C to +85°C, unless otherwise noted. Typical values are at VDD = +5V, TA=
+25°C.) (Figures 1 and 2) (Note 1)
Typical Operating Characteristics
(VDD = +5V, TA = +25°C, unless otherwise noted.)
0
0.3
0.9
0.6
1.2
1.5
-40 10-15 35 60 85
STANDBY SUPPLY CURRENT
vs. TEMPERATURE
MAX5432–35 toc01
TEMPERATURE (°C)
SUPPLY CURRENT (µA)
DIGITAL INPUTS = GND OR VDD
VDD = 5V
VDD = 3V
0
0.2
0.6
0.4
0.8
1.0
2.5 3.53.0 4.0 4.5 5.0 5.5
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX5432–35 toc02
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (µA)
DIGITAL INPUTS = GND OR VDD
02135
SUPPLY CURRENT
vs. DIGITAL INPUT VOLTAGE
MAX5432–35 toc03
DIGITAL INPUT VOLTAGE (V)
SUPPLY CURRENT (µA)
1000
0.1
1
10
100
VDD = 5V
VDD = 3V
4
VV
V
WL
H
-
31
⎛
⎝
⎜⎞
⎠
⎟
.
Note 2: The DNL and INL are measured with the potentiometer configured as a variable resistor. For the 3-terminal potentiometers
(MAX5432/MAX5433), H is unconnected and L = GND. At VDD = 5V, W is driven with a source current of 80µA for the 50kΩ
configuration, and 40µA for the 100kΩconfiguration. At VDD = 3V, W is driven with a source current of 40µA for the 50kΩ
configuration, and 20µA for the 100kΩconfiguration.
Note 3: The DNL and INL are measured with the potentiometer configured as a voltage-divider with H = VDD and L = GND
(MAX5432/MAX5433 only). The wiper terminal is unloaded and measured with an ideal voltmeter.
Note 4: Full-scale error is defined as
Note 5: Zero-scale error is defined as
Note 6: The wiper resistance is the worst value measured by injecting the currents given in Note 2 into W with L = GND.
RW= (VW - VH) / IW.
Note 7: The device draws current in excess of the specified supply current when the digital inputs are driven with voltages between
(VDD - 0.5V) and (GND + 0.5V). See the Supply Current vs. Digital Input Voltage graph in the Typical Operating Characteristics.
Note 8: Wiper is at midscale with a 10pF capacitive load. Potentiometer set to midscale, L = GND, an AC source is applied to H,
and the output is measured as 3dB lower than the DC W/H value in dB.
Note 9: This is measured from the STOP pulse to the time it takes the output to reach 50% of the output step size (divider mode). It
is measured with a maximum external capacitive load of 10pF.
Note 10: The programming current exists only during NV writes (12ms typ).
Note 11: Digital timing is guaranteed by design and characterization, and is not production tested.
Note 12: An appropriate bus pullup resistance must be selected depending on board capacitance. Refer to the I2C-bus specifica-
tion document linked to this web address: www.semiconductors.philips.com/acrobat/literature/9398/39340011.pdf
Note 13: The idle time begins from the initiation of the stop pulse.
MAX5432–MAX5435
32-Tap, Nonvolatile, I2C, Linear, Digital
Potentiometers
_______________________________________________________________________________________ 5
1.0
0.5
0
-0.5
-1.0
-40 10-15 35 60 85
END-TO-END RESISTANCE % CHANGE
vs. TEMPERATURE
MAX5432–35 toc04
TEMPERATURE (°C)
END-TO-END RESISTANCE CHANGE ( %)
50kΩ
1.0
0.5
0
-0.5
-1.0
-40 10-15 35 60 85
END-TO-END RESISTANCE % CHANGE
vs. TEMPERATURE
MAX5432-35 toc05
TEMPERATURE (°C)
END-TO-END RESISTANCE % CHANGE
100kΩ
1µs/div
TAP-TO-TAP SWITCHING TRANSIENT
(0 TO MIDSCALE, CL = 10pF)
VW
1V/div
SDA
2V/div
MAX5432–35 toc06
50kΩ
1µs/div
TAP-TO-TAP SWITCHING TRANSIENT
(0 TO MIDSCALE, CL = 10pF)
VW
1V/div
SDA
2V/div
MAX5432–35 toc07
100kΩ
10µs/div
WIPER TRANSIENT AT POWER-ON
VW
1V/div
VDD
2V/div
MAX5432–35 toc08
50kΩ
10µs/div
MIDSCALE WIPER TRANSIENT
AT POWER-ON
VW
1V/div
VDD
2V/div
MAX5432–35 toc09
100kΩ
MIDSCALE WIPER RESPONSE
vs. FREQUENCY
(MAX5432)
MAX5432 toc10
FREQUENCY (kHz)
GAIN (dB)
100101
-15
-12
-9
-6
-3
0
-18
0.1 1000
CW = 10pF
CW = 33pF
-18
-12
-15
-6
-3
-9
0
0.1 1 10 100 1000
MIDSCALE WIPER RESPONSE
vs. FREQUENCY (MAX5433)
MAX5432–35 toc11
FREQUENCY (kHz)
GAIN (dB)
CW = 10pF
CW = 33pF
0
100
300
200
500
600
400
700
08124 1620242831
WIPER RESISTANCE vs. TAP POSITION
(MAX5432)
MAX5432–35 toc12
TAP POSITION
RESISTANCE (Ω)
VDD = 3V
Typical Operating Characteristics (continued)
(VDD = +5V, TA = +25°C, unless otherwise noted.)
MAX5432–MAX5435
32-Tap, Nonvolatile, I2C, Linear, Digital
Potentiometers
6 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(VDD = +5V, TA = +25°C, unless otherwise noted.)
0
100
300
200
500
600
400
700
0812416202428
WIPER RESISTANCE vs. TAP POSITION
(MAX5433)
MAX5432-35 toc13
TAP POSITION
RESISTANCE (Ω)
VDD = 3V
31
0
100
300
200
500
600
400
700
08124 1620242831
WIPER RESISTANCE vs. TAP POSITION
(MAX5432)
MAX5432–35 toc14
TAP POSITION
RESISTANCE (Ω)
VDD = 5V
0
100
300
200
500
600
400
700
0812416202428
WIPER RESISTANCE vs. TAP POSITION
(MAX5433)
MAX5432-35 toc15
TAP POSITION
RESISTANCE (Ω)
VDD = 5V
31
0
20
10
40
90
30
120
0812416202428
W-TO-L RESISTANCE vs. TAP POSITION
MAX5432–35 toc16
TAP POSITION
W-TO-L RESISTANCE (kΩ)
110
100
80
60
50
70
50kΩ
100kΩ
31
-0.5
-0.3
-0.4
-0.1
-0.2
0.1
0
0.2
0.4
0.3
0.5
081241620242831
RESISTANCE DNL vs. TAP POSITION
MAX5432–35 toc17
TAP POSITION
RESISTANCE DNL (LSB)
VARIABLE-RESISTOR MODE
MAX5432/MAX5434
-0.5
-0.3
-0.4
-0.1
-0.2
0.1
0
0.2
0.4
0.3
0.5
081241620242831
RESISTANCE INL vs. TAP POSITION
MAX5432–35 toc18
TAP POSITION
RESISTANCE INL (LSB)
VARIABLE-RESISTOR MODE
MAX5432/MAX5434
MAX5432–MAX5435
32-Tap, Nonvolatile, I2C, Linear, Digital
Potentiometers
_______________________________________________________________________________________ 7
Typical Operating Characteristics (continued)
(VDD = +5V, TA = +25°C, unless otherwise noted.)
-0.5
-0.3
-0.4
-0.1
-0.2
0.1
0
0.2
0.4
0.3
0.5
081241620242831
RESISTANCE DNL vs. TAP POSITION
MAX5432–35 toc19
TAP POSITION
RESISTANCE DNL (LSB)
VOLTAGE-DIVIDER MODE
MAX5432
-0.5
-0.3
-0.4
-0.1
-0.2
0.1
0
0.2
0.4
0.3
0.5
081241620242831
RESISTANCE INL vs. TAP POSITION
MAX5432–35 toc20
TAP POSITION
RESISTANCE INL (LSB)
VOLTAGE-DIVIDER MODE
MAX5432
-0.5
-0.3
-0.4
-0.1
-0.2
0.1
0
0.2
0.4
0.3
0.5
0812416202428
RESISTANCE DNL vs. TAP POSITION
MAX5432-35 toc21
TAP POSITION
RESISTANCE DNL (LSB)
VARIABLE-RESISTOR MODE
MAX5433/MAX5435
31
-0.5
-0.3
-0.4
-0.1
-0.2
0.1
0
0.2
0.4
0.3
0.5
0812416202428
RESISTANCE INL vs. TAP POSITION
MAX5432-35 toc22
TAP POSITION
RESISTANCE INL (LSB)
VARIABLE-RESISTOR MODE
MAX5433/MAX5435
31
-0.5
-0.3
-0.4
-0.1
-0.2
0.1
0
0.2
0.4
0.3
0.5
0812416202428
RESISTANCE DNL vs. TAP POSITION
MAX5432-35 toc23
TAP POSITION
RESISTANCE DNL (LSB)
VOLTAGE-DIVIDER MODE
MAX5433
31
-0.5
-0.3
-0.4
-0.1
-0.2
0.1
0
0.2
0.4
0.3
0.5
0812416202428
RESISTANCE INL vs. TAP POSITION
MAX5432-35 toc24
TAP POSITION
RESISTANCE INL (LSB)
VOLTAGE-DIVIDER MODE
MAX5433
31
MAX5432–MAX5435
32-Tap, Nonvolatile, I2C, Linear, Digital
Potentiometers
8 _______________________________________________________________________________________
Detailed Description
The MAX5432–MAX5435 contain a resistor array with
31 resistive elements. The MAX5432/MAX5434 provide
a total end-to-end resistance of 50kΩ, and the
MAX5433/MAX5435 provide an end-to-end resistance
of 100kΩ.
The MAX5432/MAX5433 allow access to the high, low,
and wiper terminals for a standard voltage-divider con-
figuration. Connect H, L, and W in any desired configu-
ration as long as their voltages fall between GND and
VDD. The MAX5434/MAX5435 are variable resistors
with H internally connected to the wiper.
A simple 2-wire I2C-compatible serial interface moves
the wiper among the 32 tap points. Eight data bits, an
address byte, and a control byte program the wiper
position. A nonvolatile memory stores and recalls the
wiper position in the nonvolatile memory upon power-up.
The nonvolatile memory is guaranteed for 200,000 wiper
store cycles and 50 years for wiper data retention.
Digital Interface
The MAX5432–MAX5435 feature an internal, nonvolatile
EEPROM that returns the wiper to its previously stored
position at power-up. The shift register decodes the
control and address bits, routing the data to the proper
memory registers. Write data to the volatile memory
register to immediately update the wiper position, or
write data to the nonvolatile register for storage. Writing
to the nonvolatile register takes a minimum of 12ms.
The volatile register retains data as long as the device
is enabled and powered. Removing power clears the
volatile register. The nonvolatile register retains data
even after power is removed. Upon power-up, the
power-on reset circuitry and internal oscillator control
the transfer of data from the nonvolatile register to the
volatile register.
Serial Addressing
The MAX5432–MAX5435 operate as a slave that sends
and receives data through an I2C- and SMBus™-com-
patible 2-wire interface. The interface uses a serial data
access (SDA) line and a serial clock line (SCL) to
achieve bidirectional communication between
master(s) and slave(s). A master, typically a microcon-
troller, initiates all data transfers to and from the
MAX5432–MAX5435, and generates the SCL clock that
synchronizes the data transfer (Figure 1).
SDA operates as both an input and an open-drain out-
put. SDA requires a pullup resistor, typically 4.7kΩ.
SCL only operates as an input. SCL requires a pullup
resistor (4.7kΩtyp) if there are multiple masters on the
2-wire interface, or if the master in a single-master sys-
tem has an open-drain SCL output.
Each transmission consists of a START (S) condition
(Figure 3) sent by a master, followed by the
MAX5432–MAX5435 7-bit slave address plus the 8th bit
(Figure 4), 1 command byte (Figure 7) and 1 data byte,
and finally a STOP (P) condition (Figure 3).
Start and Stop Conditions
Both SCL and SDA remain high when the interface is
not busy. A master signals the beginning of a transmis-
sion with a START (S) condition by transitioning SDA
from high to low while SCL is high. When the master
has finished communicating with the slave, it issues a
STOP (P) condition by transitioning the SDA from low to
Pin Description
PIN
TDFN
THIN SOT23 NAME
FUNCTION
1 — H High Terminal
2 4 SDA I2C-Compatible Interface Data Input
3 2 GND Ground
4 3 SCL I2C-Compatible Interface Clock Input
51V
DD Power-Supply Input. Bypass with a 0.1µF capacitor from VDD to GND.
6 — A0 Address Input. Sets the I2C address. Connect to VDD or GND. Do not leave A0 floating.
7 6 L Low Terminal
8 5 W Wiper Terminal
EP — EP Exposed Pad. Internally connected to GND.
SMBus is a trademark of Intel Corporation.
MAX5432–MAX5435
32-Tap, Nonvolatile, I2C, Linear, Digital
Potentiometers
_______________________________________________________________________________________ 9
high while SCL is high. The bus is then free for another
transmission (Figure 3).
Bit Transfer
One data bit is transferred during each clock pulse.
The data on the SDA line must remain stable while SCL
is high (Figure 5).
Acknowledge
The acknowledge bit is a clocked 9th bit that the recip-
ient uses to handshake receipt of each byte of data
(Figure 6). Each byte transferred effectively requires 9
bits. The master generates the 9th clock pulse, and the
recipient pulls down SDA during the acknowledge
clock pulse, so the SDA line is stable low during the
high period of the clock pulse. When the master trans-
mits to the MAX5432–MAX5435, the devices generate
the acknowledge bit because the MAX5432–MAX5435
are the recipients.
Slave Address
The MAX5432–MAX5435 have a 7-bit-long slave
address (Figure 4). The 8th bit following the 7-bit slave
address is the NOP/Wbit. Set the NOP/Wbit low for a
write command and high for a no-operation command.
Table 1a shows four possible slave addresses for the
MAX5432/MAX5433 and Table 1b shows three possible
slave addresses for the MAX5434/MAX5435. The first 4
bits (MSBs) of the slave addresses are always 0101.
Bits A2 and A1 are factory programmed for the
MAX5432/MAX5433 (Table 1a). Connect the A0 input
(MAX5432/MAX5433 only) to either GND or VDD to
select one of two I2C device addresses. Each device
must have a unique address to share the bus. A maxi-
mum of four MAX5432/MAX5433 devices can share the
same bus. Bits A2, A1, and A0 are factory programmed
for the MAX5434/MAX5435 (Table 1b).
Message Format for Writing
A write to the MAX5432–MAX5435 consists of the trans-
mission of the device’s slave address with the 8th bit set
to zero, followed by at least 1 byte of information. The
1st byte of information is the command byte. The bytes
received after the command byte are the data bytes.
The 1st data byte goes into the internal register of the
MAX5432–MAX5435 as selected by the command byte
(Figure 8).
tHD-STA
tSU-DAT
tHIGH
tRtF
tHD-DAT tHD-STA
SSr A
tSU-STA
tLOW
tBUF
tSU-STO
PS
tRtF
SCL
SDA
PARAMETERS ARE MEASURED FROM 30% TO 70%.
Figure 1. I2C Serial-Interface Timing Diagram
ADDRESS BYTE
PART
SUFFIX
A6 A5 A4 A3 A2 A1 A0
NOP/W
L
0101000
NOP/W
M
0101100
NOP/W
N*
0101010
NOP/W
ADDRESS BYTE
PART
SUFFIX A6 A5 A4 A3 A2 A1 A0 NOP/W
L0101000NOP/W
L0101001NOP/W
M0101100NOP/W
M0101101NOP/W
Table 1a. Address Codes
(MAX5432/MAX5433 Only)
Table 1b. Address Codes
(MAX5434/MAX5435 Only)
*MAX5434 only.
MAX5432–MAX5435
32-Tap, Nonvolatile, I2C, Linear, Digital
Potentiometers
10 ______________________________________________________________________________________
Command Byte
Use the command byte to select the destination of the
wiper data (nonvolatile or volatile memory registers)
and swap data between nonvolatile and volatile memo-
ry registers (see Table 2).
Data Byte
The MAX5432–MAX5435 use the first 5 bits (MSBs,
D7–D3) of the data byte to set the position of the wiper.
The last 3 bits (D2, D1, and D0) are don’t care bits (see
Table 2).
Command Descriptions
VREG: The data byte writes to the volatile memory reg-
ister and the wiper position updates with the data in the
volatile memory register.
NVREG: The data byte writes to the nonvolatile memory
register. The wiper position is unchanged.
NVREGxVREG: Data transfers from the nonvolatile
memory register to the volatile memory register (wiper
position updates).
VREGxNVREG: Data transfers from the volatile memory
register into the nonvolatile memory register.
VDD
IOL = 3mA
IOH = 0mA
VOUT
400pF
SDA
Figure 2. Load Circuit
REGISTER ADDRESS BYTE COMMAND BTYE DATA BYTE
123456789101112131415161718192021222324252627
SCL CYCLE
NUMBER
START
A6 A5 A4 A3 A2 A1 A0
N
O
P/
W
A
C
K
C7 C6 C5 C4 C3 C2 C1 C0
A
C
K
D7 D6 D5 D4 D3 D2 D1 D0
A
C
K
STOP
VREG
0101A2A1A00 00010001 D7D6D5D4D3XXX
NVREG
0101A2A1A00 00100001 D7D6D5D4D3XXX
NVREGxVREG
0101A2A1A00 01100001 D7D6D5D4D3XXX
VREGxNVREG
0101A2A1A00 01010001 D7D6D5D4D3XXX
Table 2. Command Byte Summary
SDA
START
CONDITION
SCL
S
STOP
CONDITION
P
Figure 3. Start and Stop Conditions
SDA
SCL
*SEE THE Ordering Information/Selector Guide FOR OTHER ADDRESS OPTIONS.
01 A0
MSB LSB
NOP/W ACK
0 1 0* 0*
Figure 4. Slave Address
X= Don’t care.
MAX5432–MAX5435
32-Tap, Nonvolatile, I2C, Linear, Digital
Potentiometers
______________________________________________________________________________________ 11
Nonvolatile Memory
The internal EEPROM consists of a 5-bit nonvolatile
register that retains the value written to it before the
device is powered down. The nonvolatile register is
programmed with the zeros at the factory. Wait a mini-
mum of 12ms after writing to NVREG before sending
another command.
Power-Up
Upon power-up, the MAX5432–MAX5435 load the data
stored in the nonvolatile memory register into the
volatile memory register, updating the wiper position
with the data stored in the nonvolatile memory register.
This initialization period takes 20µs.
Standby
The MAX5432–MAX5435 feature a low-power standby
mode. When the device is not being programmed, it
goes into standby mode and current consumption is
typically 0.5µA.
SDA
DATA STABLE,
DATA VALID
CHANGE OF
DATA ALLOWED
SCL
Figure 5. Bit Transfer
1
SCL
START
CONDITION
SDA
289
CLOCK PULSE FOR
ACKNOWLEDGMENT
ACKNOWLEDGE
NOT ACKNOWLEDGE
Figure 6. Acknowledge
SSLAVE
ADDRESS 0A
D15 D14 D13 D12 D11 D10 D9 D8
COMMAND BYTE AP
ACKNOWLEDGE FROM
MAX5432–MAX5435
ACKNOWLEDGE FROM
MAX5432–MAX5435
NOP/W
COMMAND BYTE IS STORED ON
RECEIPT OF STOP CONDITION
Figure 7. Command Byte Received
SSLAVE ADDRESS 0A
D15 D14 D13 D12 D11 D10 D9 D8
COMMAND BYTE
ACKNOWLEDGE FROM
MAX5432–MAX5435
ACKNOWLEDGE FROM
MAX5432–MAX5435
NOP/W
HOW COMMAND BYTE AND DATA BYTE MAP
INTO MAX5432–MAX5435's REGISTERS
ADATA BYTE AP
D7 D6 D5 D4 D3 XXX
BYTE
1
ACKNOWLEDGE FROM
MAX5432–MAX5435
Figure 8. Command and Single Data Byte Received
MAX5432–MAX5435
32-Tap, Nonvolatile, I2C, Linear, Digital
Potentiometers
12 ______________________________________________________________________________________
Applications Information
Use the MAX5432–MAX5435 in applications requiring
digitally controlled adjustable resistance, such as LCD
contrast control (where voltage biasing adjusts the dis-
play contrast), or for programmable filters with
adjustable gain and/or cutoff frequency.
Positive LCD Bias Control
Figures 9 and 10 show an application where the volt-
age-divider or variable resistor is used to make an
adjustable, positive LCD bias voltage. The op-amp pro-
vides buffering and gain to the resistor-divider network
made by the potentiometer (Figure 9) or to a fixed
resistor and a variable resistor (Figure 10).
Programmable Filter
Figure 11 shows the configuration for a 1st-order pro-
grammable filter. The gain of the filter is adjusted by
R2, and the cutoff frequency is adjusted by R3. Use the
following equations to calculate the gain (G) and the
3dB cutoff frequency (fC).
Adjustable Voltage Reference
Figure 12 shows the MAX5432/MAX5433 used as the
feedback resistors in an adjustable voltage reference
application. Independently adjust the output voltages of
the MAX6160 from 1.23V to (VIN - 0.2V) by changing
the wiper position of the MAX5432/MAX5433.
GR
R
fRC
C
=+
=××
11
2
1
23π
VOUT
30V
5V
W
H
L
MAX5432
MAX5433
Figure 9. Positive LCD Bias Control Using a Voltage-Divider
VOUT
30V
5V
W
H
L
MAX5432–
MAX5435
Figure 10. Positive LCD Bias Control Using a Variable Resistor
VOUT
R1
W
H
L
R2
VIN
R3
H
W
L
C
MAX5432–
MAX5435
Figure 11. Programmable Filter
W
H
L
+5V
GND
VIN
OUT
ADJ
V0REF
V0 = 1.23V
V0 = 1.23V
100kΩ FOR THE MAX5433
50kΩ FOR THE MAX5432
R1
R2
MAX6160
MAX5432
MAX5433
R2(kΩ)
R2(kΩ)
Figure 12. Adjustable Voltage Reference
MAX5432–MAX5435
32-Tap, Nonvolatile, I2C, Linear, Digital
Potentiometers
______________________________________________________________________________________ 13
MAX5432/MAX5433 Functional Diagram
5-BIT
SHIFT
REGISTER
5-BIT
LATCH
32-
POSITION
DECODER
5-BIT
NV
MEMORY
POR
I2C
INTERFACE
5532 W
L
SDA
SCL
GND
VDD
A0
H
MAX5432
MAX5433
MAX5434/MAX5435 Functional Diagram
5-BIT
SHIFT
REGISTER
5-BIT
LATCH
32-
POSITION
DECODER
5-BIT
NV
MEMORY
POR
I2C
INTERFACE
5532 W
L
SDA
SCL
GND
VDD
MAX5434
MAX5435
MAX5432–MAX5435
32-Tap, Nonvolatile, I2C, Linear, Digital
Potentiometers
14 ______________________________________________________________________________________
Chip Information
TRANSISTOR COUNT: 7817
PROCESS: BiCMOS
Ordering Information/Selector Guide (continued)
PART PIN-PACKAGE TOP MARK I2C ADDRESS R (kΩΩ
ΩΩ) PKG CODE
MAX5434MEZT+T 6 Thin SOT23-6 AABY 0101100 50 Z6-1
MAX5434NEZT+T 6 Thin SOT23-6 AABS 0101010 50 Z6-1
MAX5435LEZT+T 6 Thin SOT23-6 AABW 0101000 100 Z6-1
MAX5435MEZT+T 6 Thin SOT23-6 AABV 0101100 100 Z6-1
*EP = Exposed pad.
**A0represents the logic state of input A0 of the device in the TDFN package.
+Denotes a lead-free package.
T = Tape and reel.
Note: All devices are specified over the -40°C to +85°C operating temperature range.
MAX5432–MAX5435
32-Tap, Nonvolatile, I2C, Linear, Digital
Potentiometers
______________________________________________________________________________________ 15
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
6, 8, &10L, DFN THIN.EPS
MAX5432–MAX5435
32-Tap, Nonvolatile, I2C, Linear, Digital
Potentiometers
16 ______________________________________________________________________________________
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
COMMON DIMENSIONS
SYMBOL MIN. MAX.
A 0.70 0.80
D 2.90 3.10
E 2.90 3.10
A1 0.00 0.05
L 0.20 0.40
PKG. CODE N D2 E2 eJEDEC SPEC b[(N/2)-1] x e
PACKAGE VARIATIONS
0.25 MIN.k
A2 0.20 REF.
2.00 REF0.25±0.050.50 BSC2.30±0.1010T1033-1
2.40 REF0.20±0.05- - - - 0.40 BSC1.70±0.10 2.30±0.1014T1433-1
1.50±0.10 MO229 / WEED-3
0.40 BSC - - - - 0.20±0.05 2.40 REFT1433-2 14 2.30±0.101.70±0.10
T633-2 6 1.50±0.10 2.30±0.10 0.95 BSC MO229 / WEEA 0.40±0.05 1.90 REF
T833-2 8 1.50±0.10 2.30±0.10 0.65 BSC MO229 / WEEC 0.30±0.05 1.95 REF
T833-3 8 1.50±0.10 2.30±0.10 0.65 BSC MO229 / WEEC 0.30±0.05 1.95 REF
2.30±0.10 MO229 / WEED-3 2.00 REF0.25±0.050.50 BSC1.50±0.1010T1033-2
MAX5432–MAX5435
32-Tap, Nonvolatile, I2C, Linear, Digital
Potentiometers
______________________________________________________________________________________ 17
6L THIN SOT23.EPS
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
MAX5432–MAX5435
32-Tap, Nonvolatile, I2C, Linear, Digital
Potentiometers
18 ______________________________________________________________________________________
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
MAX5432–MAX5435
32-Tap, Nonvolatile, I2C, Linear, Digital
Potentiometers
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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 19
© 2007 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
3 11/07
Eliminated address options, added lead-free option, updated information in Table 1b
1, 9, 14
Mouser Electronics
Authorized Distributor
Click to View Pricing, Inventory, Delivery & Lifecycle Information:
Maxim Integrated:
MAX5434NEZT+T MAX5435MEZT+T MAX5432LETA+T MAX5434LEZT+T MAX5432META+T MAX5433LETA+T
MAX5433META+T MAX5434MEZT+T MAX5435LEZT+T MAX5435NEZT+T MAX5435PEZT+T MAX5434PEZT+T
MAX5433META+