SN74LS90DR

Product Overview

• Category: Integrated Circuit (IC)
• Use: Counter
• Characteristics: TTL Logic, 4-bit Decade Counter
• Package: SOIC (Small Outline Integrated Circuit)
• Essence: The SN74LS90DR is a 4-bit decade counter IC that can count from 0 to 9 and reset back to 0.
• Packaging/Quantity: Tape and Reel, 2500 units per reel

Specifications

• Supply Voltage Range: 4.75V to 5.25V
• Operating Temperature Range: -40°C to +85°C
• Maximum Clock Frequency: 30 MHz
• Number of Pins: 16
• Logic Family: LS-TTL (Low Power Schottky Transistor-Transistor Logic)

Detailed Pin Configuration

The SN74LS90DR has 16 pins, each serving a specific function:

1. VCC: Positive power supply voltage
2. GND: Ground reference voltage
3. QA: Output for the least significant bit (LSB)
4. QB: Output for the second least significant bit
5. QC: Output for the third least significant bit
6. QD: Output for the most significant bit (MSB)
7. MR: Master Reset input, active low
8. CP: Clock Pulse input
9. RCO: Ripple Carry Output
10. CET: Count Enable input, active low
11. CEP: Count Enable input, active high
12. CETP: Count Enable input, active high, parallel load
13. CEPP: Count Enable input, active high, parallel load
14. P: Parallel Load input
15. TC: Terminal Count output
16. NC: No Connection

Functional Features

• The SN74LS90DR is a synchronous counter that counts in a decimal (0-9) sequence.
• It has a master reset input (MR) that can be used to reset the counter to 0.
• The counter advances on each positive clock pulse (CP) transition.
• The terminal count output (TC) goes high when the counter reaches its maximum value (9).
• It can be cascaded with other counters to create larger counting sequences.

Advantages and Disadvantages

Advantages: - Low power consumption due to LS-TTL technology - Compact size and easy integration into electronic circuits - Reliable and robust performance - Wide operating temperature range

Disadvantages: - Limited counting range (0-9) - Requires an external clock source for operation - Not suitable for applications requiring higher counting ranges

Working Principles

The SN74LS90DR operates based on the principle of synchronous counting. It uses flip-flops to store and propagate the count values. On each clock pulse, the stored count is incremented by one. When the count reaches 9, it resets back to 0. The master reset input (MR) allows manual resetting of the counter to 0 at any time.

Detailed Application Field Plans

The SN74LS90DR is commonly used in various applications such as:

1. Digital frequency dividers
2. Event counters
3. Time delay circuits
4. Industrial automation systems
5. Electronic voting machines
6. Traffic light control systems
7. Frequency synthesizers
8. Pulse generators

Detailed and Complete Alternative Models

Some alternative models to the SN74LS90DR include:

1. CD4017: CMOS Decade Counter/Divider IC
2. 74HC390: High-Speed CMOS Logic Dual Decade Ripple Counter
3. CD4026: CMOS Decade Counter/Divider with Decoded 7-Segment Display Outputs
4. 74F169: Synchronous Presettable Binary Counter

These alternative models offer similar functionality and can be used as replacements for the SN74LS90DR in various applications.

In conclusion, the SN74LS90DR is a 4-bit decade counter IC that finds its application in various digital counting and control systems. Its compact size, low power consumption, and reliable performance make it a popular choice among electronic designers.