FEDL9477-01

ML9477

4/20

PIN DESCRIPTION

Symbol

I/O

Description

OSC

I/O

Pin for oscillation. Has a Schmitt circuit built in.

An oscillator circuit can be configured by connecting one external resistor and one

external capacitor.

Since an oscillator circuit is susceptible to external noise, make the wiring

between this pin and external components as short as possible. An external clock

input can be selected by CLKSEL.

(*1)

DATA_IN

I

Serial data input pin. Has a Schmitt circuit built in.

The LCD display is turned on when the input data signal is at a “H” level and

turned off when the input data signal is at a “L” level.

CLOCK

I

Shift clock input pin. Has a Schmitt circuit built in.

Data to the DATA_IN pin is shifted in sync with the rising edges of the shift clock

pulses.

LOAD

I

Load pulse input pin. Has a Schmitt circuit built in.

Used to transfer serially input data to the display latch or write commands.

TEST

I

IC test pin. Has a pull-down resistor built in.

Leave this pin open or connect it to VSS when not used.

CLKSEL

I

OSC pin input switching pin.

When using the built-in oscillator circuit, set this pin to a “L” level; when inputting

an external clock, set this pin to a “H” level. While this pin is at a “H” level, the

oscillator circuit connected is disabled.

3/4SEL

I

1/3- or 1/4-duty switching input pin. When “H” level is input, 1/3 duty is selected

and when “L” level is input, 1/4 duty is selected.

RESET

I

Reset signal input pin for initializing the IC. Has a Schmitt circuit built in.

This pin is enabled by setting it to “L” level. This pin has a built-in pull-up resistor.

Normally, this pin, when connected with an external capacitor, performs power-on

reset.

(*2)

COM1

COM2

COM3

COM4

O

Output pins for LCD display. Connect to the common pins of the LCD panel.

- When 1/3 duty is selected:

Common signals are outputted through the COM1, COM2, and COM3 pins.

Leave the COM4 pin open.

- When 1/4 duty is selected:

Common signals are outputted through the COM1, COM2, COM3, and COM4

pins.

SEG1 to SEG32

O

Output pins for LCD display. Connect to the segment pins of the LCD panel.

For the relationship between each output of these pins and data, see the section

on “Data Structure.”

LVDD



Logic power supply pin.

DVDD



LCD driver power supply pin.

VSS



Ground pin.