General description
The PCF85134 is a peripheral device which interfaces to almost any LCD1 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 PCF85134 can be easily cascaded for larger LCD applications. The PCF85134 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).
FEATUREs
■ Single-chip LCD controller and driver
■ Selectable backplane drive configurations: static, 2, 3, or 4 backplane multiplexing
■ 60 segment outputs allowing to drive:
◆ 30 7-segment alphanumeric 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 twisted nematic LCDs
■ Internal LCD bias generation with voltage follower buffers
■ Selectable display bias configurations: static, 1⁄2, or 1⁄3
■ 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 microprocessor or microcontroller
■ No external components required
■ Display memory bank switching in static and duplex drive mode
■ Auto-incremented display data loading
■ Versatile blink modes
■ Silicon gate CMOS process