MAX1620

NOT RECOMMENDED FOR NEW DESIGNS

Digitally Adjustable LCD Bias Supplies

Industry's-First Digitally Controlled Positive or Negative LCD Bias Supply

Data Sheet (Rev. 1) Product Selection Table

Part Models: 2
1ku List Price: Starting From $4.20

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Overview

1.8V to 20V Battery Input Voltage
Automatic Disable when Display Logic is Shut Down
Extremely Small QSOP Package
32-Level Internal DAC
SMBus Serial Interface (MAX1621)
Positive or Negative Output Voltage

The MAX1620/MAX1621 convert a 1.8V to 20V battery voltage to a positive or negative LCD backplane bias voltage. Backplane bias voltage can be automatically disabled when the display logic voltage is removed, protecting the display. These devices use very little PC board area, come in ultra-small QSOP packages, and require only small, low-profile external components.

Output voltage can be set to a desired positive or negative voltage range with external resistors, and adjusted over that range with the on-board digital-to-analog converter (DAC) or with a potentiometer. The MAX1620/ MAX1621 include a 5-bit DAC, allowing digital software control of the bias voltage. The MAX1620 uses up/down digital signaling to adjust the DAC, and the MAX1621 uses the System Management Bus (SMBus™) 2-wire serial interface.

These devices use a low-cost, external, N-channel MOSFET power switch or NPN transistor, and can be configured for positive or negative output voltages. Operating current is a low 150µA, typically provided from a display's logic supply of 3.0V to 5.5V. The MAX1620/MAX1621 are available in a 16-pin QSOP package.

Applications

Notebook Computers
Palmtop Computers
PDAs and Other Handheld Devices
Portable Data-Collection Terminals

Part Models: 2
1ku List Price: Starting From $4.20

Documentation

Data Sheet 1

MAX1620-MAX1621: Digitally Adjustable LCD Bias Supplies Data Sheet (Rev.1) 01/01/1998

Reliability Data 1

MAX1620 Reliability Data 01/12/2023

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal. View our quality and reliability program and certifications for more information.

Part Model	Pin/Package Drawing	Documentation	CAD Symbols, Footprints, and 3D Models
MAX1620EEE+	16-QSOP-150_MIL	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
MAX1620EEE+T	16-QSOP-150_MIL	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys

Part Models	Product Lifecycle	PCN

Apr 7, 2023 - 2361C WAFER FAB
		pcn_2361c
MAX1620EEE+	PRODUCTION
MAX1620EEE+T	PRODUCTION

This is the most up-to-date revision of the Data Sheet.

Software Resources

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Hardware Ecosystem

Parts	Product Life Cycle	Description
Switching Regulators & Controllers 3
MAX629	PRODUCTION	28V, Low-Power, High-Voltage, Boost or Inverting DC-DC Converter
MAX686	PRODUCTION	DAC-Controlled Boost Inverter LCD Bias Supply with Internal Switch
MAX685	PRODUCTION	Dual-Output (Positive and Negative), DC-DC Converter for CCD and LCD

Evaluation Kits

Evaluation Kit for the MAX1620, MAX1621

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Features and Benefits

+1.8V to +12V Battery Input Voltage
+12.5V to +23.5V Adjustable Output
20mA Output
32-Level Internal DAC
10µA Shutdown Current
Surface-Mount Components
Fully Assembled and Tested

Product Details

The MAX1620 evaluation kit (EV kit) converts a +1.8V to +12V battery voltage to a +12.5V to +23.5V LCD backplane bias voltage for currents up to 20mA. Both the MAX1620 and MAX1621 include a 5-bit DAC, allowing digital software control of the bias voltage. The MAX1620 uses up/down digital signaling to adjust the DAC, and the MAX1621 uses the System Management Bus (SMBus™) 2-wire serial interface.

The MAX1620 EV kit is a fully assembled and tested surface-mount circuit board. It can also be used to evaluate the MAX1621.