WF5028 series

SEIKO NPC CORPORATION —9

FUNCTIONAL DESCRIPTION

Standby Function

When INHN goes LOW, the Q output becomes high impedance.

Power-saving Pull-up Resistor

tibility to external noise. However, the pull-up resistance ties the INHN pin HIGH level to prevent external

noise from unexpectedly stopping the output.

Oscillation Detector Function

The WF5028 series also feature an oscillation detector circuit. This circuit functions to disable the outputs until

the oscillator circuit starts and oscillation becomes stable. This alleviates the danger of abnormal oscillator out-

put at oscillator start-up when power is applied or when INHN is switched.

INHN

Q

Oscillator

HIGH (or open)

Frequency output

Normal operation

LOW

High impedance

Stopped