NXP PCF8534A多路传输通用LCD驱动方案

NXP 公司的PCF8534A是多路传输低速率通用LCD驱动器,能驱动多达4块背板和多达60段的LCD,并很容易级联以驱动更大LCD显示屏.工作电压1.8 V 到5.5 V,双向I2C总线400 kHz,和大多数的微处理器或微控制器兼容,不需要外接元件.本文介绍了PCF8534A的主要特性,方框图,典型系统配置图以及级联PCF8534A系统配置框图.

PCF8534A: Universal LCD driver for low multiplex rates

The PCF8534A is a peripheral device which interfaces to almost any LCD with low multiplex rates. It generates the drive signals for any static or multiplexed LCD containing up to four backplanes and up to 60 segments. In addition, the PCF8534A can be easily cascaded for larger LCD applications. The PCF8534A is compatible with most microprocessors or microcontrollers and communicates via a two-line bidirectional I2C-bus. Communication overheads are minimized using display RAM with auto-incremented addressing, hardware subaddressing and display memory switching (static and duplex drive modes).

The PCF8534A complies with the AEC-Q100 automotive qualification standard.

PCF8534A主要特性:

Single-chip LCD controller and driver

Selectable backplane drive configurations: static or 2, 3 or 4 backplane multiplexing

60 segment outputs allowing to drive:

30 7-segment numeric characters

16 14-segment alphanumeric characters

Any graphics of up to 240 elements

Cascading supported for larger applications

60 4-bit display data storage RAM
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Wide LCD supply range: from 2.5 V for low threshold LCDs up to 6.5 V for guest-host LCDs and high threshold (automobile) twisted nematic LCDs

Internal LCD bias generation with voltage follower buffers

Selectable display bias configurations: static, 12 or 13

Wide logic power supply range: from 1.8 V to 5.5 V

LCD and logic supplies may be separated

Low power consumption

400 kHz I2C-bus interface

Compatible with any microprocessors or microcontrollers

No external components

Display memory bank switching in static and duplex drive modes

Auto-incremented display data loading

Versatile blinking modes

Silicon gate CMOS process

图1.PCF8534A方框图



图2.PCF8534A典型系统配置图


图3.级联PCF8534A系统配置框图