74ALS161B中文资料飞利浦数据手册PDF规格书

DESCRIPTION

Synchronous presettable 4-bit binary counters (74ALS161B, 74ALS163B) feature an internal carry look-ahead and can be used for high speed counting. Synchronous operation is provided by having all flip-flops clocked simultaneously on the positive-going edge of the clock. The clock input is buffered.

The TC output is subjected to decoding spikes due to internal race conditions, Therefore, it is not recommended for use as clock or asynchronous reset for flip-flops, registers, or counters.

FEATURES

• Synchronous counting and loading

• Two count enable inputs for n-bit cascading

• Positive edge-triggered clock

• Asynchronous reset (74ALS161B)

• Synchronous reset (74ALS163B)

• High speed synchronous expansion

• Typical count rate of 140MHz