Rainbow Electronics MAX5128 User Manual
General Description
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.
Applications
V
COM
Adjustment for LCD Panels
Backlight Adjustment
LED Bias Adjustment
Power-Supply Modules
Fiber-Module Bias Setting
Bias Setting for Radios
Portable Consumer Electronics
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
MAX5128
128-Tap, Nonvolatile, Linear-Taper Digital
Potentiometer in 2mm x 2mm µDFN Package
________________________________________________________________ Maxim Integrated Products 1
19-3929; Rev 0; 1/06
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.
Ordering Information
PART
TEMP
RANGE
PIN -
PKG
CODE
M AX 5128E LA
8 µDFN
L822-1
Functional Diagram
TOP
PA C K A G E
-40°C to +85°C
MARK
AAF
H
V
CC
GND
UP
DN
SERIAL
INTERFACE
POR
7
7-BIT NV MEMORY
7
128-POSITION
DECODER
128
TAPS
MAX5128
W
L
MAX5128
128-Tap, Nonvolatile, Linear-Taper Digital
Potentiometer in 2mm x 2mm µDFN Package
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.
VCCto GND...........................................................-0.3V to +6.0V
UP and DN to GND ....................................-0.3V to (V
CC
+ 0.3V)
H, L, and W to GND....................................-0.3V to (V
CC
+ 0.3V)
Maximum Continuous Current into H, L, and W ..............±0.5mA
Maximum Continuous Current into All Other Pins ............±50mA
Continuous Power Dissipation (T
A
= +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
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
CONDITIONS
UNITS
DC PERFORMANCE (voltage-divider mode)
Resolution N 7 Bits
Integral Nonlinearity INL (Note 2)
LSB
Differential Nonlinearity DNL (Note 2)
LSB
End-to-End Resistance
Temperature Coefficient
TC
R
50
ppm/°C
Ratiometric Resistance
Temperature Coefficient
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)
LSB
Differential Nonlinearity DNL (Note 3) ±1 LSB
DC PERFORMANCE (resistor characteristics)
Wiper Resistance R
W
(Note 4) 0.6 0.8 kΩ
Wiper Capacitance C
W
20 pF
End-to-End Resistance R
HL
16 22 27 kΩ
DIGITAL INPUTS (UP, DN)
3.4V ≤ VCC ≤ 5.25V 2.4
Input-High Voltage (Note 5) V
IH
2.7V ≤ VCC < 3.4V
0.7 x
V
Input-Low Voltage V
IL
(Note 5)
0.8
V
Input Leakage Current I
IN
±1 µA
Input Capacitance C
IN
5pF
DYNAMIC CHARACTERISTICS
Wiper -3dB Bandwidth f
3dB
(Note 6)
kHz
THD Plus Noise
VH = 0.3V
RMS
, f = 1kHz, wiper set to
midscale
%
SYMBOL
MIN TYP MAX
±1.0
±1.0
THD+N
V
CC
400
0.02
±1.75
MAX5128
128-Tap, Nonvolatile, Linear-Taper Digital
Potentiometer in 2mm x 2mm µDFN Package
_______________________________________________________________________________________ 3
ELECTRICAL 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.)
(Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
NONVOLATILE MEMORY RELIABILITY
Data Retention TA = +85°C 50
Years
TA = +25°C
Endurance
T
A
= +85°C
Stores
POWER SUPPLY
Supply Voltage V
CC
V
Average Programming Current I
PG
During nonvolatile write only;
digital inputs = V
CC
or GND
400 µA
Peak Programming Current I
PK
During nonvolatile write only;
digital inputs = V
CC
or GND
4mA
Standby Current I
CC
Digital inputs = VCC or GND, TA = +25°C 0.5 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 t
S
(Note 7)
ns
DIGITAL SECTION
UP or DN Pulse-Width High t
PWH
80 ns
UP or DN Pulse-Width Low t
PWL
80 ns
UP or DN Glitch Immunity t
IMMU
20 ns
UP Fall to DN Rise Setup or DN
Fall to UP Rise Setup
t
MS1
80 ns
Before Entering NVM-Write
Mode, UP Fall to UP Rise
t
MS2
80 ns
UP Rise to DN Rise Setup when
Entering NVM-Write
t
WS
80 ns
UP Fall to DN Fall Hold or DN Fall
to UP Fall Hold during NVMWrite
t
WH
0ns
80,000
50,000
2.70 5.25
220
500
MAX5128
128-Tap, Nonvolatile, Linear-Taper Digital
Potentiometer in 2mm x 2mm µDFN Package
4 _______________________________________________________________________________________
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
CONDITIONS
MIN
TYP
MAX
UNITS
NVM-Write Mode Pulse-Width
High
t
WP
80 ns
Write NV Register Busy Time t
BUSY
14 ms
Power-Up Settling Time t
ACC
(Note 8) 2 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 = V
CC
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 (V
CC
- 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 = V
CC
, 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 V
CC
= 2.7V to the wiper settling to 1 LSB of the final value.
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