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
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
