74LS90 4-Bit Binary/Decade Counter IC – Datasheet

74LS90 is a MOD-10 decade counter that generates a BCD output code. It consists of four master-slave JK flip-flop, which is internally connected to provide MOD-2 (count to 2) counter and MOD-5 counter. 74LS90 also has an independent toggle JK flip-flop by CLKA and the other three are driven by the CLKB. The 74LS90 IC has a wide range of working voltage, a wide range of working conditions, and directly interfaces with CMOS, NMOS, and TTL. The output of the IC always comes in TTL which makes it easy to work with other TTL devices and microcontrollers.

What is a Decade Counter?

A Binary Counter is a serial digital counter that counts ten digits. it resets for every new clock input. As it can go through 10 unique combinations of output, it is also called as “Decade counter”. A binary counter can count 0000, 0001, 0010, 1000, 1001, 1010, 1011, 1110, 1111, 0000, and 0001 and so on. A 4 bit binary counter will act as a decade counter by skipping any six outputs out of the 16 (24) outputs.

74LS90 Pinout

74LS90 Pin Configuration

Pin No	Pin Name	Description
1	CLKB	Clock input B
2	R1	Reset 1
3	R2	Reset 2
4	NC	No Connection
5	VCC	Supply Voltage
6	R3	Reset 3
7	R4	Reset 4
8	Qc	Output pin 3
9	Qb	Output pin 2
10	GND	Ground Pin
11	Qd	Output pin 4
12	Qa	Output pin 1
13	NC	No Connection
14	CLKA	Clock input A

74LS90 Features & Specifications

• Technology Family: LS
• VCC (Min): 4.75V
• VCC (Max): 5.25V
• Bits: 4
• IOL (Max): 16mA
• IOH (Max): -0.4mA
• Features: High Speed (TPD 10-50ns)
• Propagation Delay: 35ns
• Operating temperature range: 0°C  to 70°C 
• Typical power dissipation: 45mW
• High count rates: 42MHz

Application

• PCs and notebooks
• Digital Electronics
• Network equipment
• Radio equipment

You can download this Datasheet for 74LS90 4-Bit Binary/Decade Counter from the link given below:

See Also: 74LS45 BCD to Decimal Decoders/Drivers IC | 74LS30 – 8 Input NAND Logic Gate IC | S8050 NPN Transistor