74LS390 Dual 4-bit Decade Counter
Package SOIC Series 74LS
74LS390 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.74LS390 monolithic circuits contain eight master-slave flip-flops and additional gating to implement two individual four-bit counters in a single package.
Datasheet
390.pdf
74LS390 features
- Eight Master-Slave Flip-Flops with Gating for Two Four-Bit Counters
- Dual Version of the 74LS90
- Direct Clear for each 4-bit Counter
- Speed up to 35MHz
- Standard TTL Switching Voltages
74LS390 pinout
| Pin | Name | Description |
|---|---|---|
| 1 | CP0' | Clock (Active LOW going edge) Input Of Counter 1 |
| 2 | MR | Master Reset (Active HIGH) Input Of Counter 1 |
| 3 | Q0 | Output Bit 0 Of Counter 1 |
| 4 | CP1' | Clock (Active LOW going edge) Input Of Counter 1 |
| 5 | Q1 | Output Bit 1 Of Counter 1 |
| 6 | Q2 | Output Bit 2 Of Counter 1 |
| 7 | Q3 | Output Bit 3 Of Counter 1 |
| 8 | GND | Ground |
| 9 | Q3 | Output Bit 3 Of Counter 2 |
| 10 | Q2 | Output Bit 2 Of Counter 2 |
| 11 | Q1 | Output Bit 1 Of Counter 2 |
| 12 | CP1' | Clock (Active LOW going edge) Input Of Counter 2 |
| 13 | Q0 | Output Bit 0 Of Counter 2 |
| 14 | MR | Master Reset (Active HIGH) Input Of Counter 2 |
| 15 | CP0' | Clock (Active LOW going edge) Input Of Counter 2 |
| 16 | VCC | Positive Supply |
74LS390 applications
- Frequency counters
- Digital clocks
- Analog to digital convertors
- With some changes in their design, counters can be used as frequency divider circuits
- In time measurement
Comments 0
Leave a comment