U2D

General description

The PCF8531 is a low-power CMOS1 LCD row and column driver, designed to drive dot matrix graphic displays at multiplex rates of 1:17, 1:26, and 1:34. Furthermore, it can drive up to 128 icons. All necessary functions for the display are provided in a single chip, including on-chip generation of VLCD and the LCD bias voltages, resulting in a minimum of external components and low power consumption. The PCF8531 is compatible with most microcontrollers and communicates via a two-line bidirectional I2C-bus. All inputs are CMOS compatible.
Remark: The icon mode is used to reduce current consumption. When only icons are displayed, a much lower operating voltage (VLCD) can be used and the switching frequency of the LCD outputs is reduced. In most applications it is possible to use VDD as VLCD.

Features and benefits

■ Single-chip LCD controller and driver
■ 34 row and 128 column outputs
■ Display data RAM 34 × 128 bits
■ 128 icons (last row is used for icons)
■ Fast-mode I2C-bus interface (400 kbit/s)
■ Software selectable multiplex rates: 1:17, 1:26, and 1:34
■ Icon mode with multiplex rate 1:2:
♦ Featuring reduced current consumption while displaying icons only
■ On-chip:
♦ Generation of VLCD (external supply also possible)
♦ Selectable linear temperature compensation
♦ Oscillator requires no external components (external clock also possible)
♦ Generation of intermediate LCD bias voltages
♦ Power-On Reset (POR)
■ No external components required
■ Software selectable bias configuration
■ Logic supply voltage range VDD1 to VSS1: 1.8 V to 5.5 V
■ Supply voltage range for on-chip voltage generator VDD2 and VDD3 to VSS1 and VSS2: 2.5 V to 4.5 V
■ Display supply voltage range VLCD to VSS:
♦ Normal mode: 4 V to 9 V
♦ Icon mode: 3 V to 9 V
■ Low-power consumption, suitable for battery operated systems
■ CMOS compatible inputs
■ Manufactured in silicon gate CMOS process

Applications

■ Telecommunication systems
■ Automotive information systems
■ Point-of-sale terminals
■ Instrumentation