CF5035 series

SEIKO NPC CORPORATION —6

FUNCTIONAL DESCRIPTION

Standby Function

When INHN goes LOW, the device is in standby mode. The Q output becomes high impedance and the oscilla-

tor circuit stops.

Power-saving Pull-up Resistor

The INHN pin pull-up resistance changes in response to the input level (HIGH or LOW). When INHN is tied

LOW, the pull-up resistance becomes large, reducing the current consumed by the resistance. When INHN is

left open, the pull-up resistance becomes small, such that even if the input is affected by external noise the out-

puts are stable due to INHN being tied HIGH by the pull-up resistor.

Oscillation Detector Function

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

oscillator circuit starts. This prevents abnormal oscillator output at oscillator start-up when power is applied or

when INHN is switched.

INHN

Q

Oscillator

HIGH (or open)

Normal operation

LOW

High impedance

Stopped