N74F1779D中文资料飞利浦数据手册PDF规格书

DESCRIPTION

The 74F1779 is a fully synchronous 8-stage up/down counter with multiplexed 3-State I/O ports for bus-oriented applications. All control functions (hold, count up, count down, synchronous load) are controlled by two mode pins (S0, S1). The device also features carry look-ahead for easy cascading. All state changes are initiated by the rising edge of the clock. When CET is High, the data outputs are held in their current state and TC is held High. the TC output is not recommended for use as a clock or asynchronous reset due to the possibility of decoding spikes.

FEATURES

• Multiplexed 3-State I/O ports for bus oriented applications

• Built-in look-ahead carry capability

• Center power pins to reduce effects of package inductance

• Count frequency 145MHz typical

• Supply current 90mA typical

• See 74F269 for 24-pin separate I/O port version

• See 74F579 for 20-pin version

• See 74F779 for 16-pin version with abbreviated function table