MAXIM MAX5424ETA

19-3371; Rev 0; 7/04
256-Tap, Nonvolatile, SPI-Interface,
Digital Potentiometers
Features
♦ Wiper Position Stored in Nonvolatile Memory
(EEPROM) and Recalled Upon Power-Up or
Interface Command
♦ 3mm x 3mm x 0.8mm TDFN Package
♦ 35ppm/°C End-to-End Resistance Temperature
Coefficient
♦ 5ppm/°C Ratiometric Temperature Coefficient
♦ 50kΩ, 100kΩ, and 200kΩ Resistor Values
♦ 5MHz SPI-Compatible Serial Interface
♦ 500nA (typ) Static Supply Current
♦ Single-Supply Operation: +2.7V to +5.25V
♦ 256 Tap Positions
♦ ±0.5 LSB DNL in Voltage-Divider Mode
♦ ±0.5 LSB INL in Voltage-Divider Mode
SPI is a trademark of Motorola, Inc.
Applications
Mechanical Potentiometer Replacement
Low-Drift Programmable Gain Amplifiers
Pin Configuration
TOP VIEW
Audio Volume Control
Liquid-Crystal Display (LCD) Contrast Control
Low-Drift Programmable Filters
Functional Diagram
H
VDD
8-BIT
SHIFT
REGISTER
8
8-BIT
LATCH
8
256256
POSITION
DECODER
SCLK
SPI
INTERFACE
DIN
8-BIT
NV
MEMORY
SCLK
2
DIN
3
CS
4
MAX5422
MAX5423
MAX5424
8
H
7
W
6
L
5
GND
TDFN (3mm x 3mm)
L
POR
1
W
GND
CS
VDD
MAX5422
MAX5423
MAX5424
Ordering Information/Selector Guide
PART
TEMP RANGE
END-TO-END
RESISTANCE (kΩ)
MAX5422ETA
-40°C to +85°C
50
8 TDFN-EP*
MAX5423ETA
-40°C to +85°C
100
8 TDFN-EP*
AII
MAX5424ETA
-40°C to +85°C
200
8 TDFN-EP*
AIH
PIN-PACKAGE
TOP MARK
AIJ
*EP = Exposed pad.
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
MAX5422/MAX5423/MAX5424
General Description
The MAX5422/MAX5423/MAX5424 nonvolatile, lineartaper, digital potentiometers perform the function of a
mechanical potentiometer, but replace the mechanics
with a simple 3-wire SPI™-compatible digital interface.
Each device performs the same function as a discrete
potentiometer or variable resistor and has 256 tap points.
The devices feature an internal, nonvolatile EEPROM
used to store the wiper position for initialization during
power-up. The 3-wire SPI-compatible serial interface
allows communication at data rates up to 5MHz, minimizing board space and reducing interconnection complexity in many applications.
The MAX5422/MAX5423/MAX5424 provide three nominal resistance values: 50kΩ (MAX5422), 100kΩ
(MAX5423), or 200kΩ (MAX5424). The nominal resistor
temperature coefficient is 35ppm/°C end-to-end and
only 5ppm/°C ratiometric. This makes the devices ideal
for applications requiring a low-temperature-coefficient
variable resistor, such as low-drift, programmable gainamplifier circuit configurations.
The MAX5422/MAX5423/MAX5424 are available in a
3mm x 3mm 8-pin TDFN package, and are specified
over the extended -40°C to +85°C temperature range.
MAX5422/MAX5423/MAX5424
256-Tap, Nonvolatile, SPI-Interface,
Digital Potentiometers
ABSOLUTE MAXIMUM RATINGS
VDD to GND ...........................................................-0.3V to +6.0V
All Other Pins to GND.................................-0.3V to (VDD + 0.3V)
Maximum Continuous Current into H, L, and W
MAX5422......................................................................±1.3mA
MAX5423......................................................................±0.6mA
MAX5424......................................................................±0.3mA
Continuous Power Dissipation (TA = +70°C)
8-Pin TDFN (derate 24.4mW/°C above +70°C) .........1951mW
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
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
(VDD = +2.7V to +5.25V, H = VDD, L = GND, TA = -40°C to +85°C. Typical values are at VDD = +5.0V, TA = +25°C, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DC PERFORMANCE (VOLTAGE-DIVIDER MODE)
Resolution
N
256
Taps
Integral Nonlinearity
INL
(Note 1)
±0.5
LSB
Differential Nonlinearity
DNL
(Note 1)
±0.5
LSB
End-to-End Resistance
Temperature Coefficient
TCR
Ratiometric Resistance
Temperature Coefficient
Full-Scale Error
Zero-Scale Error
35
ppm/°C
5
ppm/°C
MAX5422
-0.6
MAX5423
-0.3
MAX5424
-0.15
MAX5422
0.7
MAX5423
0.35
MAX5424
0.18
LSB
LSB
DC PERFORMANCE (VARIABLE-RESISTOR MODE)
Integral Nonlinearity
(Note 2)
Differential Nonlinearity
(Note 2)
INL
DNL
VDD = 3V
±3.0
VDD = 5V
±1.5
VDD = 3V, MAX5422, -40°C ≤ TA ≤ +85°C,
guaranteed monotonic
-1.0
+2.0
VDD = 3V, MAX5422, 0°C ≤ TA ≤ +85°C,
guaranteed monotonic
-1.0
+1.2
VDD = 3V, MAX5423
±1.0
VDD = 3V, MAX5424
±1.0
VDD = 5V
±1.0
LSB
LSB
DC PERFORMANCE (RESISTOR CHARACTERISTICS)
Wiper Resistance
RW
Wiper Capacitance
CW
VDD = 3V to 5.25V (Note 3)
2
675
10
MAX5422
End-to-End Resistance
325
37.5
50
62.5
MAX5423
75
100
125
MAX5424
150
200
250
_______________________________________________________________________________________
Ω
pF
kΩ
256-Tap, Nonvolatile, SPI-Interface,
Digital Potentiometers
(VDD = +2.7V to +5.25V, H = VDD, L = GND, TA = -40°C to +85°C. Typical values are at VDD = +5.0V, TA = +25°C, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DIGITAL INPUTS (CS, DIN, SCLK)
VDD = 3.4V to 5.25V
2.4
Input High Voltage (Note 4)
VIH
V
Input Low Voltage
VIL
Input Leakage Current
IIN
±0.1
Input Capacitance
CIN
5
0.7 x
VDD
VDD < 3.4V
VDD = 2.7V to 5.25V (Note 4)
0.8
V
±1
µA
pF
DYNAMIC CHARACTERISTICS
MAX5422
Wiper -3dB Bandwidth (Note 5)
100
MAX5423
50
MAX5424
25
kHz
NONVOLATILE MEMORY RELIABILITY
Data Retention
Endurance
TA = +85°C
50
TA = +25°C
200,000
TA = +85°C
50,000
Years
Stores
POWER SUPPLY
Supply Voltage
VDD
Standby Current
IDD
Digital inputs = VDD or GND, TA = +25°C
IPG
During nonvolatile write to memory; digital
inputs = VDD or GND (Note 6)
Programming Current
2.70
5.25
V
0.5
1
µA
200
400
µA
TIMING CHARACTERISTICS
(VDD = +2.7V to +5.25V, H = VDD, L = GND, TA = -40°C to +85°C. Typical values are at VDD = +5.0V, TA = +25°C, unless otherwise
noted. See Figure 1.) (Note 7)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
ANALOG SECTION
MAX5422
Wiper Settling Time (Note 8)
tS
400
MAX5423
600
MAX5424
1000
ns
DIGITAL SECTION
SCLK Frequency
fSCLK
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
tDS
50
ns
DIN to SCLK Setup
_______________________________________________________________________________________
3
MAX5422/MAX5423/MAX5424
ELECTRICAL CHARACTERISTICS (continued)
TIMING CHARACTERISTICS (continued)
(VDD = +2.7V to +5.25V, H = VDD, L = GND, TA = -40°C to +85°C. Typical values are at VDD = +5.0V, TA = +25°C, unless otherwise
noted. See Figure 1.) (Note 7)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
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
Note 1: The DNL and INL are measured with the potentiometer configured as a voltage-divider with H = VDD and L = GND. The
wiper terminal is unloaded and measured with a high-input-impedance voltmeter.
Note 2: The DNL and INL are measured with the potentiometer configured as a variable resistor. H is unconnected and L = GND.
For the 5V condition, the wiper terminal is driven with a source current of 80µA for the 50kΩ configuration, 40µA for the
100kΩ configuration, and 20µA for the 200kΩ configuration. For the 3V condition, the wiper terminal is driven with a source
current of 40µA for the 50kΩ configuration, 20µA for the 100kΩ, and 10µA for the 200kΩ configuration.
Note 3: The wiper resistance is measured using the source currents given in Note 2. For operation to VDD = 2.7V, see Maximum
Wiper Resistance vs. Temperature in the Typical Operating Characteristics.
Note 4: 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.
Note 5: Wiper at midscale with a 10pF load (DC measurement). L = GND; an AC source is applied to H; and the W output is measured. A 3dB bandwidth occurs when the AC W/H value is 3dB lower than the DC W/H value.
Note 6: The programming current operates only during power-up and NV writes.
Note 7: Digital timing is guaranteed by design and characterization, and is not production tested.
Note 8: Wiper-settling time is the worst-case 0% to 50% rise-time measured between consecutive wiper positions. H = VDD, L =
GND, and the wiper terminal is unloaded and measured with a 10pF oscilloscope probe.
Typical Operating Characteristics
(VDD = 5.0V, TA = +25°C, unless otherwise noted.)
0.05
INL (LSB)
0.10
0.05
-0.05
0
-0.05
-0.10
-0.10
-0.15
-0.15
-0.20
-0.20
-0.25
-0.25
0
32
64
96
128 160 192 224 256
TAP POSITION
MAX5422 toc03
0.15
0.10
0
VOLTAGE-DIVIDER MODE
0.20
WIPER RESISTANCE vs. TAP POSITION
700
VDD = 2.7V
ISRC = 50µA
600
RESISTANCE (Ω)
0.15
MAX5422 toc01
VOLTAGE-DIVIDER MODE
0.20
INL vs. TAP POSITION
0.25
MAX5422 toc02
DNL vs. TAP POSITION
0.25
DNL (LSB)
MAX5422/MAX5423/MAX5424
256-Tap, Nonvolatile, SPI-Interface,
Digital Potentiometers
500
400
300
200
100
0
32
64
96
128 160 192 224 256
TAP POSITION
0
0
32
64
96
128 160 192 224 256
TAP POSITION
4
_______________________________________________________________________________________
256-Tap, Nonvolatile, SPI-Interface,
Digital Potentiometers
STANDBY SUPPLY CURRENT
vs. TEMPERATURE
END-TO-END RESISTANCE %
CHANGE vs. TEMPERATURE
MAX5422 toc04
CL = 10pF
TAP = 128
H = VDD
0.8
0.6
0.9
0.8
SUPPLY CURRENT (µA)
W
1V/div
1.0
MAX5422toc05
VDD
1V/div
END-TO-END RESISTANCE % CHANGE
1.0
0.4
0.2
0
-0.2
-0.4
0.7
0.6
0.4
0.2
0.1
-1.0
0
-15
10
35
60
VDD = 4.0V
0.3
-0.8
-40
VDD = 5.25V
0.5
-0.6
4µs/div
MAX5422 toc06
WIPER TRANSIENT AT POWER-ON
VDD = 3.0V
VDD = 2.7V
-40
85
-15
10
500
400
VDD = 3.0V
300
VDD = 4.5V
200
VDD = 5.25V
400
300
200
100
100
0
-40
-15
10
35
60
2
3
4
TEMPERATURE (°C)
DIGITAL INPUT VOLTAGE (V)
THD+N RESPONSE
INL vs. TAP POSITION
(MAX5422)
MAX5422 toc09
100
1:1 RATIO
20Hz TO 20kHz BANDPASS
10
1
0
85
2.0
VARIABLE-RESISTOR MODE
VDD = 2.7V
ISRC = 50µA
1.5
1
5
MAX5422 toc10
0
1.0
INL (LSB)
THD+N (%)
85
MAX5422 toc08
500
SUPPLY CURRENT (µA)
VDD = 2.7V
RESISTANCE (Ω)
600
MAX5422 toc07
600
60
SUPPLY CURRENT
vs. DIGITAL INPUT VOLTAGE
MAXIMUM WIPER RESISTANCE
vs. TEMPERATURE
700
35
TEMPERATURE (°C)
TEMPERATURE (°C)
0.1
0.01
0.5
0
0.001
-0.5
0.0001
10
100
1k
FREQUENCY (Hz)
10k
100k
-1.0
0
32
64
96
128 160 192 224 256
TAP POSITION
_______________________________________________________________________________________
5
MAX5422/MAX5423/MAX5424
Typical Operating Characteristics (continued)
(VDD = 5.0V, TA = +25°C, unless otherwise noted.)
Typical Operating Characteristics (continued)
(VDD = 5.0V, TA = +25°C, unless otherwise noted.)
INL vs. TAP POSITION
(MAX5424)
VARIABLE-RESISTOR MODE
VDD = 2.7V
ISRC = 10µA
1.5
VARIABLE-RESISTOR MODE
0.2
0.5
0
0
0
-0.1
-0.5
-0.5
-0.2
-1.0
-1.0
0
32
64
96
128 160 192 224 256
-0.3
0
32
64
TAP POSITION
96
128 160 192 224 256
0
32
64
TAP POSITION
0.2
DNL vs. TAP POSITION
(MAX5424)
0.5
MAX5422 toc14
VARIABLE-RESISTOR MODE
128 160 192 224 256
TAP POSITION
DNL vs. TAP POSITION
(MAX5423)
0.3
96
VARIABLE-RESISTOR MODE
0.4
MAX5422 toc15
0.5
0.1
DNL (LSB)
1.0
INL (LSB)
1.0
0.3
MAX5422 toc12
VARIABLE-RESISTOR MODE
VDD = 2.7V
ISRC = 20µA
1.5
2.0
MAX5422 toc11
2.0
DNL vs. TAP POSITION
(MAX5422)
0.3
DNL (LSB)
DNL (LSB)
0.1
0
0.2
0.1
0
-0.1
-0.1
-0.2
-0.2
-0.3
-0.3
0
32
64
96
128 160 192 224 256
TAP POSITION
6
MAX5422 toc13
INL vs. TAP POSITION
(MAX5423)
INL (LSB)
MAX5422/MAX5423/MAX5424
256-Tap, Nonvolatile, SPI-Interface,
Digital Potentiometers
0
32
64
96
128 160 192 224 256
TAP POSITION
_______________________________________________________________________________________
256-Tap, Nonvolatile, SPI-Interface,
Digital Potentiometers
PIN
NAME
1
VDD
FUNCTION
2
SCLK
Serial-Interface Clock Input
3
DIN
Serial-Interface Data Input
4
CS
Active-Low Digital-Input Chip Select
5
GND
Power-Supply Input. Bypass VDD with a 0.1µF capacitor from VDD to GND.
Ground
6
L
Low Terminal. The voltage at L can be greater than or less than the voltage at H. Current can flow into or
out of L.
7
W
Wiper Terminal
8
H
High Terminal. 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. The exposed pad is not internally connected. Connect to GND or leave floating.
CS
tCSW
tCS0
tCSS
tCL
tCH
tCP
tCSH
tCS1
SCLK
tDS
tDH
DIN
Figure 1. Digital Interface and Timing Diagram
Detailed Description
The MAX5422/MAX5423/MAX5424 contain a resistor
array with 255 resistive elements. The MAX5422 has a
total end-to-end resistance of 50kΩ; the MAX5423 has
an end-to-end resistance of 100kΩ; and the MAX5424
has an end-to-end resistance of 200kΩ. The
MAX5422/MAX5423/MAX5424 allow access to the high,
low, and wiper terminals for a standard voltage-divider
configuration. H, L, and W can be connected in any
desired configuration as long as their voltages fall
between GND and VDD.
A simple, 3-wire, SPI serial interface moves the wiper
among the 256 tap points. The nonvolatile memory
stores the wiper position and recalls the stored wiper
position upon power-up. The nonvolatile memory is
guaranteed for 50 years for wiper data retention and up
to 200,000 wiper store cycles.
Analog Circuitry
The MAX5422/MAX5423/MAX5424 consist of a resistor
array with 255 resistive elements; 256 tap points are
accessible to the wiper, W, along the resistor string
between H and L. Select the wiper tap point by programming the potentiometer through the 3-wire (SPI)
interface. Eight data bits, and a control byte program
the wiper position. The H and L terminals of the
MAX5422/MAX5423/MAX5424 are similar to the two
end terminals of a mechanical potentiometer. The
MAX5422/MAX5423/MAX5424 feature power-on reset
circuitry that loads the wiper position from the nonvolatile memory at power-up.
Digital Interface
The MAX5422/MAX5423/MAX5424 use a 3-wire, SPIcompatible, serial data interface (Figure 1 and 2). This
write-only interface contains three inputs: chip-select
_______________________________________________________________________________________
7
MAX5422/MAX5423/MAX5424
Pin Description
MAX5422/MAX5423/MAX5424
256-Tap, Nonvolatile, SPI-Interface,
Digital Potentiometers
(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 and data (Figure
2a). The COPY commands (C1, C0 = 10, 11) can use
either eight clock cycles to transfer the command bits
(Figure 2b) or 16 clock cycles with 8 data bits that are
disregarded by the device (Figure 2a).
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.
The serial-data timing for the potentiometer is shown in
Figures 1 and 2.
Table 1. Register Map
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Bit name
CLOCK EDGE
—
—
C1
C0
—
—
—
—
D7
D6
D5
D4
D3
D2
D1
D0
Write wiper register
0
0
0
0
0
0
0
0
D7
D6
D5
D4
D3
D2
D1
D0
Write NV register
0
0
0
1
0
0
0
0
D7
D6
D5
D4
D3
D2
D1
D0
Copy wiper register to NV
register
0
0
1
0
0
0
0
0
—
—
—
—
—
—
—
—
Copy NV register to wiper
register
0
0
1
1
0
0
0
0
—
—
—
—
—
—
—
—
A) 16-BIT COMMAND/DATA WORD
CS
SCLK
1
2
DIN
3
4
C1
C0
3
4
C1
C0
5
6
7
8
9
10
11
12
13
14
15
16
D7
D6
D5
D4
D3
D2
D1
D0
B) 8-BIT COMMAND WORD
CS
SCLK
1
DIN
2
5
6
7
8
Figure 2. Digital-Interface Format
8
_______________________________________________________________________________________
256-Tap, Nonvolatile, SPI-Interface,
Digital Potentiometers
Write NV Register
The “write NV register” 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 writes to the NV register. Writing to the
NV registers, does not affect the position of the wipers.
Copy Wiper Register to NV Register
The “copy wiper register to NV register” command (C1,
C0 = 10) stores the current position of the wiper to the
NV register for use at power-up.
Copy NV Register to Wiper Register
The “copy NV register to wiper register” (C1, C0 = 11)
restores the wiper position to the current value stored in
the NV register.
Standby Mode
The MAX5422/MAX5423/MAX5424 feature a low-power
standby mode. When the device is not being pro-
grammed, it enters into standby mode and supply current drops to 0.5µA (typ).
Nonvolatile Memory
The internal EEPROM consists of a nonvolatile register
that retains the last value stored prior to power-down.
The nonvolatile register is programmed to midscale at
the factory. The nonvolatile memory is guaranteed for
50 years for wiper data retention and up to 200,000
wiper write cycles.
Power-Up
Upon power-up, the MAX5422/MAX5423/MAX5424
load the data stored in the nonvolatile wiper register
into the volatile wiper register, updating the wiper position with the data stored in the nonvolatile wiper register. This initialization period takes 10µs.
Applications Information
The MAX5422/MAX5423/MAX5424 are intended for circuits requiring digitally controlled adjustable resistance, such as LCD contrast control (where voltage
biasing adjusts the display contrast), or programmable
filters with adjustable gain and/or cutoff frequency.
Positive LCD Bias Control
Figures 3 and 4 show an application where a voltagedivider or variable resistor is used to make an
adjustable, positive LCD-bias voltage. The op amp provides buffering and gain to the resistor-divider network
made by the potentiometer (Figure 3) or to a fixed
resistor and a variable resistor (see Figure 4).
5V
5V
H
30V
30V
W
MAX5422
MAX5423
MAX5424
L
VOUT
H
VOUT
MAX5422
MAX5423
MAX5424
W
L
Figure 3. Positive LCD-Bias Control Using a Voltage-Divider
Figure 4. Positive LCD-Bias Control Using a Variable Resistor
_______________________________________________________________________________________
9
MAX5422/MAX5423/MAX5424
Write Wiper Register
Data written to this register (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 random
access memory (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.
MAX5422/MAX5423/MAX5424
256-Tap, Nonvolatile, SPI-Interface,
Digital Potentiometers
Programmable Filter
Adjustable Voltage Reference
Figure 5 shows the configuration for a 1st-order programmable 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 DC gain (G) and
the 3dB cutoff frequency (fC):
Figure 6 shows the MAX5422/MAX5423/MAX5424 used
as the feedback resistors in an adjustable voltage-reference application. Independently adjust the output
voltage of the MAX6160 from 1.23V to VIN - 0.2V by
changing the wiper position of the MAX5422/
MAX5423/MAX5424.
R1
G = 1+
fC =
Offset Voltage and Gain Adjustment
R2
Connect the high and low terminals of one potentiometer of a MAX5422/MAX5423/MAX5424 between the
NULL inputs of a MAX410 and the wiper to the op
amp’s positive supply to nullify the offset voltage over
the operating temperature range. Install another
MAX5422/MAX5423/MAX5424 potentiometer in the
feedback path to adjust the gain of the MAX410 (see
Figure 7).
1
2π × R 3 × C
C
VIN
5V
VOUT
H
MAX5422
R3
R1
W
7
2
L
1
H
8
6
MAX5422
MAX5423
MAX5424
MAX410
R2
W
3
4
-5V
L
Figure 7. Offset Voltage Adjustment Circuit
Figure 5. Programmable Filter
Chip Information
+5V
VIN
V0 REF
OUT
TRANSISTOR COUNT: 10,191
PROCESS: BiCMOS
H
MAX6160
ADJ
MAX5422
MAX5423
MAX5424
GND
W
L
V0 = 1.23V 50kΩ FOR THE MAX5422
R2(kΩ)
100kΩ
V0 = 1.23V
FOR THE MAX5423
R2(kΩ)
200kΩ
V0 = 1.23V
FOR THE MAX5424
R2(kΩ)
Figure 6. Adjustable Voltage Reference
10
______________________________________________________________________________________
256-Tap, Nonvolatile, SPI-Interface,
Digital Potentiometers
6, 8, &10L, DFN THIN.EPS
D
N
PIN 1
INDEX
AREA
E
E2
DETAIL A
CL
CL
L
A
L
e
e
PACKAGE OUTLINE, 6, 8, 10 & 14L,
TDFN, EXPOSED PAD, 3x3x0.80 mm
21-0137
NUMBER OF LEADS SHOWN ARE FOR REFERENCE ONLY
F
1
2
COMMON DIMENSIONS
SYMBOL
A
MIN.
0.70
0.80
D
2.90
3.10
E
2.90
3.10
A1
L
0.00
0.05
k
MAX.
0.40
0.20
0.25 MIN.
A2
0.20 REF.
PACKAGE VARIATIONS
PKG. CODE
N
D2
E2
e
JEDEC SPEC
b
T633-1
6
1.50±0.10
2.30±0.10
0.95 BSC
MO229 / WEEA
0.40±0.05
1.90 REF
T833-1
8
1.50±0.10
2.30±0.10
0.65 BSC
MO229 / WEEC
0.30±0.05
1.95 REF
2.00 REF
[(N/2)-1] x e
T1033-1
10
1.50±0.10
2.30±0.10
0.50 BSC
MO229 / WEED-3
0.25±0.05
T1433-1
14
1.70±0.10
2.30±0.10
0.40 BSC
----
0.20±0.03
2.40 REF
T1433-2
14
1.70±0.10
2.30±0.10
0.40 BSC
----
0.20±0.03
2.40 REF
PACKAGE OUTLINE, 6, 8, 10 & 14L,
TDFN, EXPOSED PAD, 3x3x0.80 mm
21-0137
F
2
2
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 ____________________ 11
© 2004 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
MAX5422/MAX5423/MAX5424
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.)