SM5168 series

SEIKO NPC CORPORATION —8

DO Output Timing

The phase comparator error signal charge pump signal is output on DO with polarity for connection to an

external passive filter. The signals compared are FV and FR, which are the internal comparator frequency

divider output signal and reference frequency divider output signal, respectively. The timing is shown in the

following figure.

INPUT/OUTPUT EQUIVALENT CIRCUITS

DO

FIN

TR

TEST

LD

XIN

FR

FV

DO

LD

Lagging

correction signal

Leading

correction signal

DO

To

internal counter

FIN

From

internal circuit

TYP100k

Ω

To internal circuit

TR

To

internal circuit

TEST

From internal circuit

LD

To

internal counter

XIN

From

internal circuit

TYP100k

Ω