GENERAL DESCRIPTION

The PCF8531 is a low power CMOS LCD row/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 bus (I2C-bus). All inputs are CMOS compatible.

Remark: The icon mode is used to save current. 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

• Single-chip LCD controller/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 Mux 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.

• No external components required

• Software selectable bias configuration

• Logic supply voltage range VDD1 to VSS1 1.8 to 5.5 V

• Supply voltage range for on-chip voltage generator VDD2 and VDD3 to VSS1 and VSS2 2.5 to 4.5 V

• Display supply voltage range VLCD to VSS:

– Normal mode 4 to 9 V

– Icon mode 3 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.