General description
The PCF8579 is a low power CMOS1 LCD column driver, designed to drive dot matrix graphic displays at multiplex rates of 1:8, 1:16, 1:24 or 1:32. The device has 40 outputs and can drive 32 × 40 dots in a 32 row multiplexed LCD. Up to 16 PCF8579s can be cascaded and up to 32 devices may be used on the same I2C-bus (using the two slave addresses). The device is optimized for use with the PCF8578 LCD row/column driver.

Features
■ LCD column driver
■ Used in conjunction with the PCF8578, this device forms part of a chip set capable of driving up to 40960 dots
■ 40 column outputs
■ Selectable multiplex rates; 1:8, 1:16, 1:24 or 1:32
■ Externally selectable bias configuration, 5 or 6 levels
■ Easily cascadable for large applications (up to 32 devices)
■ 1280-bit RAM for display data storage
■ Display memory bank switching
■ Auto-incremented data loading across hardware subaddress boundaries (with PCF8578)
■ Power-On Reset (POR) blanks display
■ Logic voltage supply range 2.5 V to 6 V
■ Maximum LCD supply voltage 9 V
■ Low power consumption
■ I2C-bus interface
■ Compatible with most microcontrollers
■ Optimized pinning for single plane wiring in multiple device applications (with PCF8578)
■ Space saving 56-lead small outline package and 64-pin quad flat pack

Applications
■ Automotive information systems
■ Telecommunication systems
■ Point-of-sale terminals
■ Industrial computer terminals
■ Instrumentation