SN74LS390NSR

Product Overview

• Category: Integrated Circuit (IC)
• Use: Digital Counter
• Characteristics:
  • Dual 4-bit Decade Counter
  • Synchronous Counting
  • Asynchronous Clear
  • Package: SOIC (Small Outline Integrated Circuit)
  • Essence: High-speed, low-power TTL logic
  • 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
• Maximum Propagation Delay: 20 ns
• Input Current: ±1 mA
• Output Current: ±8 mA

Pin Configuration

The SN74LS390NSR has a total of 16 pins. The detailed pin configuration is as follows:

1. CLK (Clock Input)
2. MR (Master Reset Input)
3. QA (Output A)
4. QB (Output B)
5. QC (Output C)
6. QD (Output D)
7. GND (Ground)
8. VCC (Supply Voltage)
9. RC (Ripple Carry Output)
10. RCO (Ripple Carry Output Enable)
11. QA' (Complement of Output A)
12. QB' (Complement of Output B)
13. QC' (Complement of Output C)
14. QD' (Complement of Output D)
15. CET (Count Enable Trickle)
16. CET' (Complement of Count Enable Trickle)

Functional Features

• Dual 4-bit decade counter with synchronous counting
• Asynchronous clear function for resetting the counter
• Ripple carry output for cascading multiple counters
• Complementary outputs for each counter stage
• Count enable trickle input for controlling the counter operation

Advantages and Disadvantages

Advantages

• High-speed operation suitable for time-critical applications
• Low-power consumption for energy-efficient designs
• Compact SOIC package for space-constrained layouts
• Synchronous counting ensures accurate and reliable results
• Asynchronous clear function allows easy counter reset

Disadvantages

• Limited maximum clock frequency of 30 MHz
• Propagation delay of 20 ns may impact timing-sensitive applications
• Requires external components for complete counter functionality

Working Principles

The SN74LS390NSR is a dual 4-bit decade counter that operates on TTL logic. It counts in synchronous mode, meaning all flip-flops within the counter change state simultaneously on each clock pulse. The counter can be cleared asynchronously using the master reset input (MR). The ripple carry output (RC) enables cascading multiple counters to create larger counting sequences.

Detailed Application Field Plans

The SN74LS390NSR is commonly used in various applications, including:

1. Digital frequency dividers
2. Event counters
3. Timekeeping circuits
4. Industrial automation systems
5. Electronic test equipment
6. Communication devices

Detailed and Complete Alternative Models

1. CD4017BE: CMOS Decade Counter with 10 Outputs
2. 74HC393: Dual 4-bit Binary Ripple Counter
3. CD4029BE: CMOS Presettable Up/Down Counter

These alternative models offer similar functionality and can be used as replacements for the SN74LS390NSR in different applications.

In conclusion, the SN74LS390NSR is a dual 4-bit decade counter IC with synchronous counting and asynchronous clear function. It offers high-speed operation, low-power consumption, and comes in a compact SOIC package. While it has limitations in terms of clock frequency and propagation delay, it finds applications in various fields such as digital frequency dividers, event counters, and industrial automation systems. Alternative models like CD4017BE, 74HC393, and CD4029BE provide similar functionality options.