74LS669 Synchronous 4-Bit Up/Down Counter
A versatile 4-bit binary counter with synchronous operation and carry lookahead feature.
- Supply Voltage: 4.75 - 5.25V
- Operating Ambient Temperature Range: 70°C
- Output Current — High: –0.4mA
- Output Current — Low: 8.0mA
- Input HIGH Voltage: 2.0V
- Input LOW Voltage: 0.8V
- Input Clamp Diode Voltage: -0.65 - -1.5V
- Short Circuit Current: -100mA
- Power Supply Current: 34mA
Features:
- Programmable Look-Ahead Up/Down Binary/Decade Counters
- Fully Synchronous Operation for Counting and Programming
- Internal Look-Ahead for Fast Counting
- Carry Output for n-Bit Cascading
The 74LS669 is a synchronous 4-bit up/down counter with internal carry lookahead for cascading. It provides synchronous operation to eliminate output counting spikes. The counter features four master-slave flip-flops triggered on the rising edge of the clock waveform. The load inputs allow loading with the carry-enable output of cascaded counters, enabling synchronous loading and disabling of the counter. The carry look-ahead circuitry facilitates cascading counters for N-bit synchronous applications without additional gating.
Two count-enable inputs (P and T) must both be low to count, and the up-down input determines the count direction. The carry output produces low-level output pulses for cascading stages. The counter is designed to minimize transmission line effects and simplify system design.
Package Includes:
- 1 X 74LS669 Synchronous 4-Bit Up/Down Binary Counter IC (74669) DIP-14 Package
Images are for illustration only; actual product may vary.