74LS168-Synch Decade Up/Down Counter
Package SOIC Series 74LS
74LS168 overview
The 74LS series of integrated circuits (ICs) was one of the most popular logic families of transistor-transistor logic (TTL) logic chips. 74LS series is a bipolar, low-power Schottky IC. The 74LS168 is a fully synchronous 4-stage up/down counter featuring a preset capability for programmable operation, carry lookahead for easy cascading, and a U/D input to control the direction of counting.
Key specifications
Supply Voltage
4.75 - 5.25Vdc
Maximum Clock Frequency
40Mhz
Power Dissipation
2mW/gate @100kHz
Minimum Output Current
8mA
Propagation Delay
10nS
Fan Out (TTL Loads)
20
Datasheet
168.pdf
74LS168 features
- Low Power Dissipation 100 mW Typical
- High-Speed Count Frequency 30 MHz Typical
- Fully Synchronous Operation
- Full Carry Lookahead for Easy Cascading
- Single Up/Down Control Input
- Positive Edge-Trigger Operation
74LS168 pinout
| Pin | Name | Description |
|---|---|---|
| 1 | U/D | Up-Down Count Control Input |
| 2 | CP | Clock Pulse (Active positive-going edge) Input |
| 3 | P0 | Parallel Data Input Of Counter 0 |
| 4 | P1 | Parallel Data Input Of Counter 1 |
| 5 | P2 | Parallel Data Input Of Counter 2 |
| 6 | P3 | Parallel Data Input Of Counter 3 |
| 7 | CEP | Count Enable Parallel (Active LOW) Input |
| 8 | GND | Ground |
| 9 | PE' | Parallel Enable (Active LOW) Input |
| 10 | CET' | Count Enable Trickle (Active LOW) Input |
| 11 | Q3 | Counter Output Q3 |
| 12 | Q2 | Counter Output Q2 |
| 13 | Q1 | Counter Output Q1 |
| 14 | Q0 | Counter Output Q0 |
| 15 | TC' | Terminal Count (Active LOW) Output |
| 16 | VCC | Positive Supply |
74LS168 applications
- Clock generation
- Clock division
- Integrated oscillator
- Low power CMOS
- TTL compatible inputs
- In frequency counting circuits
More about 74LS168
74LS168 Alternative Equivalent
74LS169
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