NXP PCF8576C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40段的LCD,并很容易级联以驱动更大LCD显示屏.具有多种闪光模式,通过双向I2C总线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PCF8576C的主要特性,级联PCF8576C系统配置框图以及单面配线框图.

PCF8576C:Universal LCD driver for low multiplex rates

The PCF8576C is a peripheral device which interfaces to almost any Liquid Crystal Display (LCD) with low multiplex rates. It generates the drive signals for any static or multiplexed LCD containing up to four backplanes and up to 40 segments and can easily be cascaded for larger LCD applications. The PCF8576C is compatible with most microprocessors or microcontrollers and communicates via a two-line bidirectional I2C-bus. Communication overheads are minimized by a display RAM with auto-incremented addressing, by hardware subaddressing.

PCF8576C主要特性:

Single-chip LCD controller and driver

40 segment drives:

Up to twenty 7-segment numeric characters

Up to ten 14-segment alphanumeric characters

Any graphics of up to 160 elements

Versatile blinking modes

No external components required (even in multiple device applications)

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

Selectable display bias configuration: static, 12 or 13

Internal LCD bias generation with voltage-follower buffers

40.4-bit RAM for display data storage

Auto-incremented display data loading across device subaddress boundaries

Display memory bank switching in static and duplex drive modes

Wide logic LCD supply range:

From 2 V for low-threshold LCDs

Up to 6 V for guest-host LCDs and high-threshold twisted nematic LCDs

Low power consumption

May be cascaded for large LCD applications (up to 2560 segments possible)

Cascadable with 24-segment LCD driver PCF8566

No external components

Compatible with chip-on-glass technology

Separate or combined LCD and logic supplies

Optimized pinning for plane wiring in both and multiple PCF8576C applications

Power-saving mode for extremely low power consumption in battery-operated and telephone applications

图1.PCF8576C方框图

图2.级联PCF8576C系统配置图

图3. PCF8576CT单面配线框图