Analog, Discrete Electronic Components, ICs Compare
74LS90 7490 4-BIT Binary Decade BCD Counter IC
74LS90 Binary Counter Features
- It is used as a simple counter from 0 – 9.
- The IC has the ability to start from 0 and end at 9 automatically.
- IC can be used any TTL based device and microcontroller due to its TTL output.
- The IC has low power consumption.
- IC comes in multiple packages, PDSO, PDIP, and GDIP
- The IC has internal protection from clamp voltages.
SPECIFICATION
- The Power input range for IC is 4.75 to 5.25.
- The operating temperature range for IC is 0 to 70.
- The input voltages range for IC at HIGH state is 2.0 minimum and the LOW state is 0.7 maximum.
- IC draws output current at HIGH state is -0.4mA and for the LOW state is 8.0mA
- The internal clamp diode protection range is -1.5V.
More information is available in the datasheet:
Availability:
In stock
₨ 70
In stock
74LS90 is basically a MOD-10 decade counter that generate a BCD output code. It consists of four master-slave JK flip-flop, which are internally connected to provide MOD-2 (count to 2) counter and MOD-5 counter. 74LS90 also have an independent toggle JK flip-flop by CLKA and other three are driven by the CLKB.
Internal Logic Diagram
74LS90 Pin Configuration
| Pin No. | Pin Name | Description |
| 1 | CLKB | Clock Input 2 |
| 2 | R1 | Reset 1 |
| 3 | R2 | Reset 2 |
| 4 | NC | Not Connected |
| 5 | Vcc | Positive Supply Input |
| 6 | R3 | Reset 3 |
| 7 | R4 | Reset 4 |
| 8 | Qc | Output Pin 3 |
| 9 | Qb | Output Pin 2 |
| 10 | Gnd | Ground |
| 11 | Qd | Output Pin 4 |
| 12 | Qa | Output Pin 1 |
| 13 | NC | Not Connected |
| 14 | CLKA | Clock Input 1 |
- Typical power dissipation: 45mW
- High count rates: 42MHz
- Choice of counting modes
- Input Clamp Diodes Limit High-Speed Termination Effect
- Supply voltage: 5V
- Operating Ambient Temperature Range: –55 to 125°C
