INTRODUCTION

ST7541 is a driver & controller LSI for 4-level gray scale graphic dot-matrix liquid crystal display systems. This chip can connect directly to a microprocessor which supports: Serial Peripheral Interface (SPI), IIC or 8-bit parallel interface. Display data stores in an on-chip display data RAM of 128 x 129 x 2 bits. It performs display data RAM read/write operation with no external operating clock to minimize power consumption.

FEATURES

4-level Gray Scale

–Display with PWM and FRC Methods

Driver OutputCircuits

128 segment outputs/ 128+1 common outputs

ApplicableDutyRatios

– V arious partial display

–Partial window moving & data scrolling

On-chipDisplay Data RAM

–Capacity: 128 × 129 × 2=33,024 bits

Microprocessor Interface

– 8-bit bi-directional parallel interface supports 6800-series or 8080-series MPU

– 4-line serial interface(4-LineSPI)

– 3-line serial interface(3-Line 8-bit SPI)

– IIC serial interface

On-chip Low PowerAnalogCircuit

– On-chip oscillator circuit

– Voltage booster (x3, x4, x5 or x6)

– Voltageregulator (temperature coefficient: -0.144/˚C, or external input)

– On-chip electronic contrast controlfunction(64 steps X 8)

– Voltage follower (LCD bias: 1/5to 1/12)

Operating V oltage Range

–Supply voltage(VDD): 1.8to 3.3V

–Supply voltage(VDD2): 2.4 to 3.3V

– LCD driving voltage(VLCD =V0- VSS): 3.5 to 15.0V Package Type

– Applicationfor COG