No. 5625-8/11

LB1872

Continued from preceding page.

Pin No.

Symbol

Pin function

Equivalent circuit

20

LD

Phase lock detector output

This pin goes to the on state when the PLL phase is locked. This is an

open collector output.

21

N2

Divisor switch

Low: 0 to 1.0 V

Middle: 2.0 to 3.0 V

This pin goes to the middle level when open.

22

N1

Divisor switch and external clock input

Low: 0 to 1.5 V

This pin functions as the external clock input pin when N2 is at the

middle level.

This pin goes to the high level when open.

23

S/S

Start/stop control

Low: Start

High: Stop

This pin goes to the high level when open.

24

FGS

FG pulse-converted output

This pin outputs the post-hysteresis comparator FG signal.

This is an open collector output.

25

FG amplifier output

If noise in the FG signal is a problem, e.g. if discharge noise is

detected, insert a capacitor (about 0.01 to 0.1 µF) between this pin and

ground.

Continued on next page.

FG schmitt comparator