74LS90 Decade Counter
Package DIP, SOIC Series 74LS
74LS90 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. 74LS90 monolithic counters contain four master-slave flip-flops and additional gating to provide a divide-by-two counter and a three-stage binary counter.
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
90.pdf
74LS90 features
- Contains a divide-by-two Counter and a Three Stage Binary Counter
- Count Frequency 42MHz
- Low Power Dissipation
- Operating Temperature up to 70°C
- Standard TTL Switching Voltages
74LS90 pinout
| Pin | Name | Description |
|---|---|---|
| 1 | CP1' | Invert Clear Pin 1 |
| 2 | MR1 | Master Reset 1 |
| 3 | MR2 | Master Reset 2 |
| 4 | NC | Not Connected |
| 5 | VCC | Positive Supply |
| 6 | MS1 | Master Set 1 |
| 7 | MS2 | Master Set 2 |
| 8 | Q2 | Output Q2 |
| 9 | Q1 | Output Q1 |
| 10 | GND | Ground Pin |
| 11 | Q3 | Output Q3 |
| 12 | Q0 | Output Q0 |
| 13 | NC | Not Connected |
| 14 | CP0' | Invert Clear Pin 0 |
74LS90 applications
- Clock generation
- Clock division
- Integrated oscillator
- Low power cmos
- TTL compatible inputs
- In frequency counting circuit
Application circuit
More about 74LS90
74LS90 Circuit
Here is a simple circuit of Mod 10 Counter using 74LS90 IC.
74LS90 Alternative Equivalent
74LS162, 74LS190
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