Overview

The LC75857E and LC75857W are 1/3 duty and 1/4 duty LCD display drivers that can directly drive up to 164 segments and can control up to four general-purpose output ports. These products also incorporate a key scan circuit that accepts input from up to 30 keys to reduce printed circuit board wiring.

Features

• Key input function for up to 30 keys (A key scan is performed only when a key is pressed.)

• 1/3 duty and 1/4 duty drive schemes can be controlled from serial data.

• 1/2 bias and 1/3 bias drive schemes can be controlled from serial data.

• Capable of driving up to 126 segments using 1/3 duty and up to 164 segments using 1/4 duty.

• Sleep mode and all segments off functions that are controlled from serial data.

• Switching between key scan output and segment output can be controlled from the serial data.

• The key scan operation enabled/disabled state can be controlled from the serial data.

• Switching between segment output port and general-purpose output port can be controlled

from serial data.

• The common and segment output waveform frame frequency can be controlled from the

serial data.

• Switching between RC oscillator mode and external clock mode can be controlled from the

serial data.

• Serial data I/O supports CCB format communication with the system controller.

• Direct display of display data without the use of a decoder provides high generality.

• Independent VLCD for the LCD driver block.

(When the logic block supply voltage VDD is in the range 3.6 to 6.0 V, VLCD can be set to a

voltage in the range 0.75 × VDD to 6.0 V, and when VDD is in the range 2.7 to 3.6 V, VLCD

can be set to a voltage in the range 2.7 to 6.0 V.)

• Provision of an on-chip voltage-detection type reset circuit prevents incorrect displays.