MAXIM MAX5128

19-3929; Rev 2; 6/07
KIT
ATION
EVALU
LE
B
A
IL
A
AV
128-Tap, Nonvolatile, Linear-Taper Digital
Potentiometer in 2mm x 2mm µDFN Package
The MAX5128 nonvolatile, single, linear-taper, digital
potentiometer performs the function of a mechanical
potentiometer, but replaces the mechanics with a simple 2-wire digital interface. The MAX5128 performs the
same function as a discrete potentiometer or variable
resistor and features 128 taps and 22kΩ end-to-end
resistance. The MAX5128 also features an ultra-small,
2mm x 2mm µDFN package and low 0.5µA (typ) standby supply current, making this device ideal for portable
applications. The MAX5128 operates from a +2.7V to
+5.25V power supply. An integrated nonvolatile memory recalls the programmed wiper position of the digital
potentiometer. A simple 2-wire up/down interface programs the wiper position. The digital potentiometer provides a low 5ppm/°C ratiometric temperature coefficient
and is specified over the extended -40°C to +85°C temperature range.
Features
♦ Ultra-Small, 2mm x 2mm, 8-Pin µDFN Package
♦ Power-On Recall of Wiper Position from
Nonvolatile Memory
♦ 22kΩ End-to-End Resistance
♦ 128 Tap Positions
♦ 5ppm/°C Ratiometric Temperature Coefficient
♦ 1.5µA (max) Standby Supply Current
♦ +2.7V to +5.25V Single Supply Operation
♦ 80,000 Wiper Store Cycles
♦ 50-Year Wiper Data Retention
Applications
Ordering Information
VCOM Adjustment for LCD Panels
PART
Backlight Adjustment
TEMP
RANGE
LED Bias Adjustment
MAX5128ELA+ -40°C to +85°C
Power-Supply Modules
+Denotes a lead-free package.
PINTOP
PACKAGE MARK
PKG
CODE
8 µDFN
L822-1
AAF
Fiber-Module Bias Setting
Bias Setting for Radios
Portable Consumer Electronics
Functional Diagram
H
VCC
POR
7-BIT NV MEMORY
7
GND
128-POSITION
DECODER
128
TAPS
W
L
UP
DN
SERIAL
INTERFACE
7
MAX5128
________________________________________________________________ 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
MAX5128
General Description
MAX5128
128-Tap, Nonvolatile, Linear-Taper Digital
Potentiometer in 2mm x 2mm µDFN Package
ABSOLUTE MAXIMUM RATINGS
VCC to GND ...........................................................-0.3V to +6.0V
UP and DN to GND ....................................-0.3V to (VCC + 0.3V)
H, L, and W to GND....................................-0.3V to (VCC + 0.3V)
Maximum Continuous Current into H, L, and W ..............±0.5mA
Maximum Continuous Current into All Other Pins ............±50mA
Continuous Power Dissipation (TA = +70°C)
8-Pin µDFN (derate 4.7mW/°C above +70°C) ........376.5mW
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
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
(VCC = +2.7V to +5.25V, H = VCC, L = GND, TA = -40°C to +85°C. Typical values are at VCC = +5.0V, TA = +25°C, unless otherwise noted.)
(Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DC PERFORMANCE (voltage-divider mode)
Resolution
N
7
Bits
Integral Nonlinearity
INL
(Note 2)
±1.0
LSB
Differential Nonlinearity
DNL
(Note 2)
±1.0
LSB
End-to-End Resistance
Temperature Coefficient
TCR
Ratiometric Resistance
Temperature Coefficient
50
ppm/°C
5
ppm/°C
Full-Scale Error
FSE
-3
0
LSB
Zero-Scale Error
ZSE
0
+2
LSB
DC PERFORMANCE (variable-resistor mode)
Integral Nonlinearity
INL
(Note 3)
±1.75
LSB
Differential Nonlinearity
DNL
(Note 3)
±1
LSB
0.8
kΩ
27
kΩ
DC PERFORMANCE (resistor characteristics)
Wiper Resistance
RW
Wiper Capacitance
CW
End-to-End Resistance
RHL
(Note 4)
0.6
20
16
22
pF
DIGITAL INPUTS (UP, DN)
Input-High Voltage (Note 5)
VIH
Input-Low Voltage
VIL
Input Leakage Current
IIN
Input Capacitance
CIN
3.4V ≤ VCC ≤ 5.25V
2.4
2.7V ≤ VCC < 3.4V
0.7 x
VCC
V
(Note 5)
0.8
V
±1
µA
5
pF
(Note 6)
400
kHz
VH = 0.3VRMS, f = 1kHz, wiper set to
midscale
0.02
%
DYNAMIC CHARACTERISTICS
Wiper -3dB Bandwidth
THD Plus Noise
2
f3dB
THD+N
_______________________________________________________________________________________
128-Tap, Nonvolatile, Linear-Taper Digital
Potentiometer in 2mm x 2mm µDFN Package
(VCC = +2.7V to +5.25V, H = VCC, L = GND, TA = -40°C to +85°C. Typical values are at VCC = +5.0V, TA = +25°C, unless otherwise noted.)
(Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
NONVOLATILE MEMORY RELIABILITY
Data Retention
Endurance
TA = +85°C
50
TA = +25°C
80,000
TA = +85°C
50,000
Years
Stores
POWER SUPPLY
Supply Voltage
VCC
2.70
Average Programming Current
IPG
During nonvolatile write only;
digital inputs = VCC or GND
220
Peak Programming Current
IPK
During nonvolatile write only;
digital inputs = VCC or GND
4
Standby Current
ICC
Digital inputs = VCC or GND, TA = +25°C
0.5
5.25
V
400
µA
mA
1.5
µA
TIMING CHARACTERISTICS
(VCC = +2.7V to +5.25V, H = VCC, L = GND, TA = -40°C to +85°C. Typical values are at VCC = +5.0V, TA = +25°C, unless otherwise noted.)
(See Figures 1, 2, 3, and 4).
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
ANALOG SECTION
Wiper Settling Time
tS
(Note 7)
500
ns
DIGITAL SECTION
UP or DN Pulse-Width High
tPWH
80
ns
UP or DN Pulse-Width Low
tPWL
80
ns
UP or DN Glitch Immunity
tIMMU
20
ns
UP Fall to DN Rise Setup or DN
Fall to UP Rise Setup
tMS1
80
ns
Before Entering NVM-Write
Mode, UP Fall to UP Rise
tMS2
80
ns
UP Rise to DN Rise Setup when
Entering NVM-Write
tWS
80
ns
UP Fall to DN Fall Hold or DN Fall
to UP Fall Hold during NVMWrite
tWH
0
ns
_______________________________________________________________________________________
3
MAX5128
ELECTRICAL CHARACTERISTICS (continued)
MAX5128
128-Tap, Nonvolatile, Linear-Taper Digital
Potentiometer in 2mm x 2mm µDFN Package
TIMING CHARACTERISTICS (continued)
(VCC = +2.7V to +5.25V, H = VCC, L = GND, TA = -40°C to +85°C. Typical values are at VCC = +5.0V, TA = +25°C, unless otherwise noted.)
(See Figures 1, 2, 3, and 4).
PARAMETER
SYMBOL
NVM-Write Mode Pulse-Width
High
tWP
Write NV Register Busy Time
tBUSY
Power-Up Settling Time
tACC
CONDITIONS
MIN
TYP
MAX
80
ns
14
(Note 8)
UNITS
2
ms
µs
Note 1: All devices are production tested at TA = +25°C and are guaranteed by design for TA = -40°C to +85°C.
Note 2: The DNL and INL are measured with the potentiometer configured as a voltage-divider with H = VCC and L = GND. The
wiper terminal is unloaded and measured with a high input-impedance voltmeter.
Note 3: 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 200µA and for the +2.7V condition, the wiper terminal is driven with a source current of 100µA.
Note 4: The wiper resistance is measured using the source currents given in Note 3.
Note 5: The device draws higher supply current when the digital inputs are driven with voltages between (VCC - 0.5V) and (GND +
0.5V). See Supply Current vs. Digital Input Voltage in the Typical Operating Characteristics.
Note 6: Wiper at midscale with a 10pF load, 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 7: Wiper-settling time is the worst-case 0 to 50% rise time measured between consecutive wiper positions. H = VCC, L = GND,
and the wiper terminal is unloaded and measured with a 10pF oscilloscope probe. See the Tap-to-Tap Switching Transient
in the Typical Operating Characteristics section.
Note 8: Power-up settling time is measured from the time VCC = 2.7V to the wiper settling to 1 LSB of the final value.
4
_______________________________________________________________________________________
128-Tap, Nonvolatile, Linear-Taper Digital
Potentiometer in 2mm x 2mm µDFN Package
0.08
0.06
0.02
INL (LSB)
0.04
0.04
0.02
0.04
0.02
0
0
0
-0.02
-0.02
-0.02
-0.04
-0.04
-0.04
-0.06
-0.06
12 24 36 48 60 72 84 96 108 120
CODE
VCC = 2.7V, TA = -40°C
0.006
0.010
0.008
VCC = 2.7V, TA = +25°C
0.006
DIFFERENTIAL NONLINEARITY
vs. CODE (VOLTAGE-DIVIDER)
0.010
0.008
0
0.004
DNL (LSB)
DNL (LSB)
0.002
0.002
0
-0.002
-0.002
0.002
0
-0.002
-0.004
-0.004
-0.004
-0.006
-0.006
-0.006
-0.008
-0.008
-0.008
-0.010
-0.010
CODE
1.5
VCC = 2.7V, TA = +25°C
1.0
1.5
VCC = 2.7V, TA = +85°C
1.0
0.5
0
0.5
INL (LSB)
INL (LSB)
0.5
INL (LSB)
INTEGRAL NONLINEARITY
vs. CODE (VARIABLE RESISTOR)
MAX5128 toc08
1.0
CODE
INTEGRAL NONLINEARITY
vs. CODE (VARIABLE RESISTOR)
MAX5128 toc07
VCC = 2.7V, TA = -40°C
0 12 24 36 48 60 72 84 96 108 120
CODE
INTEGRAL NONLINEARITY
vs. CODE (VARIABLE RESISTOR)
1.5
-0.010
0 12 24 36 48 60 72 84 96 108 120
0 12 24 36 48 60 72 84 96 108 120
0
0
-0.5
-0.5
-0.5
-1.0
-1.0
-1.0
-1.5
-1.5
0 12 24 36 48 60 72 84 96 108 120
CODE
VCC = 2.7V, TA = +85°C
0.006
0.004
0.004
12 24 36 48 60 72 84 96 108 120
CODE
DIFFERENTIAL NONLINEARITY
vs. CODE (VOLTAGE-DIVIDER)
MAX5128 toc04
0.008
0
12 24 36 48 60 72 84 96 108 120
CODE
DIFFERENTIAL NONLINEARITY
vs. CODE (VOLTAGE-DIVIDER)
0.010
-0.06
0
MAX5128 toc05
0
VCC = 2.7V, TA = +85°C
0.10
0.06
INL (LSB)
INL (LSB)
0.12
MAX5128 toc03
0.08
0.06
DNL (LSB)
VCC = 2.7V, TA = +25°C
0.10
MAX5128 toc06
0.08
0.12
INTEGRAL NONLINEARITY
vs. CODE (VOLTAGE-DIVIDER)
MAX5128 toc09
VCC = 2.7V, TA = -40°C
0.10
MAX5128 toc01
0.12
INTEGRAL NONLINEARITY
vs. CODE (VOLTAGE-DIVIDER)
MAX5128 toc02
INTEGRAL NONLINEARITY
vs. CODE (VOLTAGE-DIVIDER)
-1.5
0 12 24 36 48 60 72 84 96 108 120
CODE
0 12 24 36 48 60 72 84 96 108 120
CODE
_______________________________________________________________________________________
5
MAX5128
Typical Operating Characteristics
(VCC = +5.0V, TA = +25°C, unless otherwise noted.)
Typical Operating Characteristics (continued)
(VCC = +5.0V, TA = +25°C, unless otherwise noted.)
DIFFERENTIAL NONLINEARITY
vs. CODE (VARIABLE RESISTOR)
0.15
0.20
VCC = 2.7V, TA = +25°C
0.15
0.10
0.10
0.05
0.05
0.25
VCC = 2.7V, TA = +85°C
0.20
0.15
0
DNL (LSB)
DNL (LSB)
0.10
0
-0.05
-0.05
-0.10
-0.10
-0.15
-0.15
-0.20
-0.20
0.05
0
-0.05
-0.10
-0.15
-0.20
-0.25
0 12 24 36 48 60 72 84 96 108 120
CODE
RATIOMETRIC TEMPERATURE
COEFFICIENT vs. CODE (VOLTAGE-DIVIDER)
VCC = 2.7V
TA = -40°C TO +85°C
120
TA = -40°C TO +85°C
800
VCC = 2.7V
700
600
100
80
60
40
500
400
300
200
20
100
0
0
-20
-100
12 24 36 48 60 72 84 96 108 120
0 12 24 36 48 60 72 84 96 108 120
CODE
CODE
END-TO-END RESISTANCE (RHL)
% CHANGE vs. TEMPERATURE
STANDBY SUPPLY CURRENT
vs. TEMPERATURE
1.5
MAX5128 toc15
1.0
0.8
0.6
MAX5128 toc16
0
1.2
0.4
0.2
IDD (μA)
END-TO-END RESISTANCE CHANGE (%)
900
TCVR (ppm/°C)
RATIOMETRIC TEMPCO (ppm/°C)
140
TEMPERATURE COEFFICIENT
vs. CODE (VARIABLE RESISTOR)
MAX5128 toc13
160
0
-0.2
0.9
VCC = 5.25V
VCC = 3.3V
0.6
-0.4
-0.6
VCC = 2.7V
0.3
-0.8
-1.0
0
-40
-15
10
35
TEMPERATURE (°C)
6
0 12 24 36 48 60 72 84 96 108 120
CODE
CODE
MAX5128 toc14
0 12 24 36 48 60 72 84 96 108 120
60
85
-40
-15
10
35
60
TEMPERATURE (°C)
_______________________________________________________________________________________
85
MAX5128 toc12
VCC = 2.7V, TA = -40°C
MAX5128 toc10
0.20
DIFFERENTIAL NONLINEARITY
vs. CODE (VARIABLE RESISTOR)
MAX5128 toc11
DIFFERENTIAL NONLINEARITY
vs. CODE (VARIABLE RESISTOR)
DNL (LSB)
MAX5128
128-Tap, Nonvolatile, Linear-Taper Digital
Potentiometer in 2mm x 2mm µDFN Package
128-Tap, Nonvolatile, Linear-Taper Digital
Potentiometer in 2mm x 2mm µDFN Package
VCC = 5V
WIPER = MIDSCALE
800
0
VCC = 5V
WIPER = MIDSCALE
-2
-4
100
MAX5128 toc19
1000
MAX5128 toc18
VCC = 5V
MAX5128 toc17
1000
WIPER RESPONSE
vs. FREQUENCY
WIPER RESISTANCE
vs. TEMPERATURE
SUPPLY CURRENT
vs. DIGITAL INPUT VOLTAGE
GAIN (dB)
RW (Ω)
10
400
-8
-10
-12
1
-14
200
-16
-18
0
0.1
-40
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
-15
10
35
60
0.1
85
1
THD+N vs. FREQUENCY
10
100
1000
FREQUENCY (kHz)
TEMPERATURE (°C)
DIGITAL INPUT VOLTAGE (V)
TAP-TO-TAP SWITCHING TRANSIENT
MAX5128 toc21
MAX5128 toc20
10
VCC = 5V
WIPER = MIDSCALE
FILTER BANDWIDTH = 80kHz
1
THD+N (%)
UP
2V/div
0.1
0.01
H = VCC
L = GND
FROM MIDSCALE
CW = 20pF
0.001
0.0001
0.1
1
10
100
VW
20mV/div
AC-COUPLED
1μs/div
FREQUENCY (kHz)
MIDSCALE WIPER TRANSIENT
AT POWER-ON
WIPER RESISTANCE vs. CODE
MAX5128 toc23
600
MAX5128 toc22
0
500
VCC
2V/div
400
RW (Ω)
IDD (μA)
-6
600
300
OUTPUT
W
2V/div
200
100
0
0 12 24 36 48 60 72 84 96 108 120
10μs/div
CODE
_______________________________________________________________________________________
7
MAX5128
Typical Operating Characteristics (continued)
(VCC = +5.0V, TA = +25°C, unless otherwise noted.)
128-Tap, Nonvolatile, Linear-Taper Digital
Potentiometer in 2mm x 2mm µDFN Package
MAX5128
Pin Description
PIN
NAME
FUNCTION
1
VCC
Power Supply. Bypass VCC with a 0.1µF capacitor to GND as close to the device as possible. For proper
operation, limit the supply voltage slew rate to ≥ 10µs.
2
H
High Terminal. The voltage at H can be higher than or lower than the voltage at L. Current can flow into or
out of H.
3
W
Wiper Terminal
4
L
Low Terminal. The voltage at L can be higher than or lower than the voltage at H. Current can flow into or out
of L.
5
GND
6
DN
Down Input
7
UP
Up Input
8
N.C.
tPWH
Ground
No Connection. Not internally connected.
NVM WRITE
tPWL
tMS1
UP
tPWL
tPWH
tWP
DN
tMS1
tWH
tWS
Figure 1. Digital-Interface Timing Diagram
Detailed Description
The MAX5128 nonvolatile, single, linear-taper, digital
potentiometer performs the function of a mechanical
potentiometer or variable resistor, but replaces the
mechanics with a simple 2-wire digital interface. This
device features 128 taps and 22kΩ end-to-end resistance with a 5ppm/°C ratiometric temperature coefficient. The MAX5128 operates from a +2.7V to +5.25V
power supply and consumes only 0.5µA (typ) of standby supply current. The MAX5128 includes an integrated nonvolatile memory that recalls the stored wiper
position of the digital potentiometer. A simple 2-wire
up/down interface programs the wiper positions.
8
Analog Circuitry
The MAX5128 consists of a resistor array with 127
resistive elements; 128 tap points along the resistor
string between H and L are accessible to the wiper, W.
Select the wiper tap point by programming the potentiometer through the 2-wire (UP, DN) interface.
The MAX5128 features power-on reset circuitry that
loads the wiper position from the nonvolatile memory at
power-up.
The nonvolatile memory is programmed to midscale at
the factory.
_______________________________________________________________________________________
128-Tap, Nonvolatile, Linear-Taper Digital
Potentiometer in 2mm x 2mm µDFN Package
NVM
WRITE
t MS2
t PWL
MAX5128
t PWH
t BUSY
UP
t WP
DN
t WS
t WH
Figure 2. Digital-Interface Timing Diagram with tBUSY
tBUSY
tBUSY
UP
DN
WIPER
INCREMENTS
WIPER
DECREMENTS
NVM
WRITE
NVM
WRITE
WIPER
INCREMENTS
WIPER
DECREMENTS
Figure 3. Digital-Interface Command Diagram
Digital Interface
The MAX5128 features a 2-wire interface consisting of
two logic inputs (UP and DN). Logic inputs UP and DN
control the wiper position and program the position to
the nonvolatile memory. Transition UP from high to low
with DN low to increment the wiper position. Transition
DN from high to low with UP low to decrement the wiper
position (see Figures 1, 2, and 3). When the wiper decrements, it decreases the resistance between W and L
(and it increases the resistance between H and W).
To program the nonvolatile memory, force UP high,
then force DN high, and then transition either input
(UP/DN) from high to low (see Figure 3).
The wiper performs a make-before-break transition,
ensuring that an open circuit during a transition from
one resistor tap to another does not occur. The wiper
does not wrap around when it reaches either end of the
resistor array (max/min). Additional transition com-
mands in the direction of the end point do not change
the tap position.
The logic inputs also feature pulse glitch immunity
(20ns) to protect the wiper from transitioning due to
glitches (see Figure 4).
Write NV Register
The internal EEPROM consists of a 7-bit nonvolatile
memory that retains the value written to it even after
power-down. To program the nonvolatile memory, force
UP high, then force DN high, and then transition either
input (UP/DN) from high to low. A nonvolatile write
requires a busy time of 14ms (max). During the busy
time, any nonvolatile write requests are ignored as well
as requests to increment or decrement the wiper position. Upon power-up, the wiper returns to the position
stored in the nonvolatile register. The MAX5128 features a factory-default wiper position of midscale.
_______________________________________________________________________________________
9
MAX5128
128-Tap, Nonvolatile, Linear-Taper Digital
Potentiometer in 2mm x 2mm µDFN Package
tIMMU
tIMMU
UP
DN
tIMMU
tIMMU
PULSES WITH WIDTHS LESS THAN tIMMU ARE IGNORED.
Figure 4. Glitch-Immunity Timing Diagram
Standby Mode
DC-DC Converter Applications
The MAX5128 operates in standby mode while the serial interface is inactive. Programming the MAX5128
increases the average operating current to 400µA
(max). When in standby mode, the static supply current
reduces to less than 0.5µA (typ).
Figures 6 and 7 show two applications using the
MAX5128 to adjust the output voltage of a DC-DC converter. Figure 6 shows the MAX5128 in the grounded
potentiometer configuration. Figure 7 shows the
MAX5128 in a floating potentiometer configuration. The
grounded potentiometer configuration forces the output
voltage range of the DC-DC converter to fall within the
supply voltage range of the MAX5128. Use the floating
potentiometer configuration to allow the DC-DC converter’s output to exceed the supply voltage range of
the MAX5128. The floating potentiometer configuration
increases the output voltage range and increases the
precision of the output voltage adjustment range.
Power-Up
Upon power-up, the MAX5128 updates the wiper position with the data stored in the nonvolatile memory. This
initialization period takes 2µs (typ). For proper operation, limit the supply voltage slew rate to ≥ 10µs.
Applications Information
Use the MAX5128 for applications requiring digitally
controlled adjustable resistance or voltage, such as
LCD contrast control (where voltage biasing adjusts the
display contrast), or DC-DC converters with adjustable
outputs. The 22kΩ end-to-end resistance is divided into
128 tap points of 172Ω each. Use the MAX5128 in a
voltage-divider or variable-resistor configuration.
VCOM Generator
Figure 5 shows an application using the MAX4238 and
the MAX5128 to generate the VCOM voltage for a LCD
panel. Adjusting the resistor value of the MAX5128
changes the VCOM voltage. Adjusting the VCOM voltage changes the contrast for the LCD panel.
10
LED Bias Adjustment
Figure 8 shows a LED bias adjustment application
using a MAX5128 to set the current of the LEDs that the
MAX1574 drives. Use the MAX5128 for an adjustable
LED current drive of 10mA to 60mA.
Chip Information
PROCESS: BiCMOS
______________________________________________________________________________________
128-Tap, Nonvolatile, Linear-Taper Digital
Potentiometer in 2mm x 2mm µDFN Package
MAX5128
+3.3V
15kΩ
120kΩ
+5V
H
0.1μF
TIMING-CONTROL-IC
OUTPUT SIGNAL
MAX5128
W
10kΩ
MAX4238
+3.3V
22kΩ
L
VCOM
51kΩ
27kΩ
36kΩ
0.1μF
Figure 5. VCOM Generator Circuit for LCD Panels
VOUT = 2V
TO 5.25V
OUT
LX
H
MAX1722
VIN = 0.8V
TO VOUT
FB
W
BATT
MAX5128
GND
L
Figure 6. DC-DC Converter Using a Grounded Potentiometer
______________________________________________________________________________________
11
MAX5128
128-Tap, Nonvolatile, Linear-Taper Digital
Potentiometer in 2mm x 2mm µDFN Package
SW
VOUT = VCC TO 28V
LX
H
MAX8574
VCC = 2.7V TO 5.5V
VCC
FB
SHDN
W
MAX5128
L
GND
Figure 7. DC-DC Converter Using a Floating Potentiometer
Pin Configuration
CN
VIN = 2.7V
TO 5.5V
IN
TOP VIEW
CP
OUT
N.C.
UP
DN
GND
8
7
6
5
MAX1574
LED1
MAX5128
H
W
MAX5128
LED2
SET
LED3
L
1
2
3
4
VCC
H
W
L
2mm x 2mm μDFN
GND
Figure 8. LED Bias Adjustment Using the MAX5128
12
______________________________________________________________________________________
128-Tap, Nonvolatile, Linear-Taper Digital
Potentiometer in 2mm x 2mm µDFN Package
XXXX
XXXX
XXXX
b
e
N
SOLDER
MASK
COVERAGE
E
PIN 1
0.10x45∞
L
PIN 1
INDEX AREA
6, 8, 10L UDFN.EPS
A
D
L1
1
SAMPLE
MARKING
A
A
(N/2 -1) x e)
7
CL
b
L
A
A2
A1
CL
L
e
EVEN TERMINAL
e
ODD TERMINAL
PACKAGE OUTLINE,
6, 8, 10L uDFN, 2x2x0.80 mm
-DRAWING NOT TO SCALE-
21-0164
A
1
2
______________________________________________________________________________________
13
MAX5128
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.)
MAX5128
128-Tap, Nonvolatile, Linear-Taper Digital
Potentiometer in 2mm x 2mm µDFN Package
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.
NOM.
A
0.70
0.75
0.80
A1
0.15
0.20
0.25
0.035
A2
0.020
0.025
D
1.95
2.00
E
1.95
2.00
L
0.30
0.40
L1
MAX.
-
2.05
2.05
0.50
0.10 REF.
PACKAGE VARIATIONS
PKG. CODE
N
e
b
(N/2 -1) x e
L622-1
6
0.65 BSC
0.30±0.05
1.30 REF.
L822-1
8
0.50 BSC
0.25±0.05
1.50 REF.
L1022-1
10
0.40 BSC
0.20±0.03
1.60 REF.
PACKAGE OUTLINE,
6, 8, 10L uDFN, 2x2x0.80 mm
21-0164
-DRAWING NOT TO SCALE-
A
2
2
Revision History
Pages changed at Rev 1: 1, 9, 10, 13
Pages changed at Rev 2: 1, 9–14
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.
14 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2007 Maxim Integrated Products
Boblet
is a registered trademark of Maxim Integrated Products, Inc.