PCF8579

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 blanks display
· Logic voltage supply range 2.5 to 6 V
· Maximum LCD supply voltage 9 V
· Low power consumption
· I2C-bus interface
· TTL/CMOS compatible
· Compatible with most microcontrollers
· Optimized pinning for single plane wiring in multiple device applications (with PCF8578)
· Space saving 56-lead plastic mini-pack and 64-pin plastic low profile quad flat package
· Compatible with chip-on-glass technology
· I2C-bus address: 011110 SA0.


Application

· Automotive information systems
· Telecommunication systems
· Point-of-sale terminals
· Computer terminals
· Instrumentation.


Pinout




Specifications

SYMBOL	PARAMETER	MIN.	MAX.	UNIT
VDD	supply voltage	-0.5	+8.0	V
VLCD	LCD supply voltage	VDD -11	VDD	V
VI1	input voltage pins SDA, SCL, SYNC, CLK, TEST, SA0, A0, A1, A2 and A3	VSS - 0.5	VDD + 0.5	V
VI2	input voltage pins V3 and V4	VLCD - 0.5	VDD + 0.5	V
Vo1	output voltage pin SDA	VSS - 0.5	VDD + 0.5	V
Vo2	output voltage pins C0 to C39	VLCD - 0.5	VDD + 0.5	V
II	DC input current	-10	+10	mA
IO	DC output current	-10	+10	mA
IDD, ISS, ILCD	current at pins VDD, VSS or VLCD	-50	+50	mA
Ptot	total power dissipation per package	-	400	mW
PO	power dissipation per output	-	100	mW
Tstg	storage temperature	-65	+150

Description

The PCF8579 is a low power CMOS 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.

Together these two devices form a general purpose LCD dot matrix driver chip set, capable of driving displays of up to 40960 dots. The PCF8579 is compatible with most microcontrollers and communicates via a two-line bidirectional bus (I2C-bus). To allow partial VDD shutdown the ESD protection system of the SCL and SDA pins of PCF8579 does not use a diode connected to VDD. Communication overheads are minimized by a display RAM with auto-incremented addressing and display bank switching.