No. 5213-2/16

LC74725, 74725M

Pin Assignment

Pin Functions

Pin No.

Symbol

Function

Description

1

Ground

Ground connection (digital system ground)

2

Connections for the external crystal and capacitors used to form a crystal oscillator for internal

Crystal oscillator

synchronizing signal generation. Alternatively, these pins can be used for external clock input

3

(2fsc or 4fsc).

4

CTRL1

Crystal oscillator input

Switches between external clock input mode and crystal oscillator mode. Low: crystal oscillator

switching

mode, high: external clock input mode.

5

LN21

Data output

Line 21H pulse output (MOD0 = low: even field, MOD0 = high: both fields output)

6

LC oscillator

Connections for the external coil and capacitor used to form the character output dot clock

7

generation oscillator.

Outputs the judgment as to where there are or are not external synchronizing signals present.

Outputs a high level when there are synchronizing signals.

External synchronizing

SEL0 = high: Outputs field discrimination pulses (O/E pulses)

8

signal judgment output

Outputs the dot clock (LC oscillator) when the CS1 pin is high and the RST pin is low. A

command is provided that turns this output off.

Outputs the crystal oscillator clock when the CS1 pin is low and the RST pin is low. A

command is provided that turns this output off.

9

CS1

Enable input

Enable input for OSD serial data input. Serial data input is enabled when this pin is low. A pull-

up resistor is built in (hysteresis input).

10

SCLK

Clock input

Serial data input clock input.

A pull-up resistor is built in (hysteresis input).

11

SIN

Data input

Serial data input. A pull-up resistor is built in (hysteresis input).

12

Power supply

Composite video signal level adjustment power supply (analog system power supply)

13

Video signal output

Composite video signal output pin

14

NC

Must be either connected to ground or left open.

15

Video signal input

Composite video signal input pin

16

Power supply

Power supply (+5 V: digital system power supply)

17

Sync separator circuit input

Video signal input to the built-in sync separator circuit

18

Ground

Ground (digital system ground)

19

Composite synchronizing

Video signal output from the built-in sync separator circuit

signal output

Vertical synchronizing

20

signal input

21

CS2

Enable input

Enable input for EDS data output. EDS data output is enabled when this input is low. A pull-up

resistor is built in (hysteresis input).

22

CPDT

Data output

EDS data output (either an n-channel open-drain or a CMOS output circuit)

23

RST

Reset input

System reset input. A pull-up resistor is built in (hysteresis input).

24

Power supply (+5 V)

Power supply (+5 V: digital system power supply)