MAX5128ELA+T Maxim Integrated Products, MAX5128ELA+T Datasheet - Page 10

• Manufacturer Part Number: MAX5128ELA+T
• Description: IC POT DGTL LP 128TAP 8-UDFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX5128ELA+T

• Taps: 128
• Resistance (ohms): 22K
• Number Of Circuits: 1
• Temperature Coefficient: 50 ppm/°C Typical
• Memory Type: Non-Volatile
• Interface: Up/Down
• Voltage - Supply: 2.7 V ~ 5.25 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-µDFN
• Resistance In Ohms: 22K
• Number Of Pots: Single
• Taps Per Pot: 128
• Resistance: 22 KOhms
• Wiper Memory: Non Volatile
• Digital Interface: Serial (2-Wire)
• Operating Supply Voltage: 2.7 V to 5.25 V
• Supply Current: 1.5 uA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Description/function: 128-Tap Nonvolatile Linear Taper Digital Potentiometer
• Mounting Style: SMD/SMT
• Supply Voltage (max): 5.25 V
• Supply Voltage (min): 2.7 V
• Tolerance: 25 %
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: MAX5128ELA+TTR

The MAX5128 operates in standby mode while the seri-
al 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).
Upon power-up, the MAX5128 updates the wiper posi-
tion with the data stored in the nonvolatile memory. This
initialization period takes 2µs (typ). For proper opera-
tion, limit the supply voltage slew rate to ≥ 10µs.
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.
Figure 5 shows an application using the MAX4238 and
the MAX5128 to generate the V
panel. Adjusting the resistor value of the MAX5128
changes the V
age changes the contrast for the LCD panel.
128-Tap, Nonvolatile, Linear-Taper Digital
Potentiometer in 2mm x 2mm µDFN Package
Figure 4. Glitch-Immunity Timing Diagram
10
DN
UP
PULSES WITH WIDTHS LESS THAN t
______________________________________________________________________________________
t
IMMU
COM
Applications Information
voltage. Adjusting the V
IMMU
ARE IGNORED.
t
IMMU
COM
V
COM
Standby Mode
voltage for a LCD
Generator
Power-Up
COM
volt-
Figures 6 and 7 show two applications using the
MAX5128 to adjust the output voltage of a DC-DC con-
verter. 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 con-
verter’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.
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.
PROCESS: BiCMOS
DC-DC Converter Applications
t
IMMU
t
IMMU
Chip Information
LED Bias Adjustment