SN74LS257BNSR

Product Overview

• Category: Integrated Circuit (IC)
• Use: Data Selector/Multiplexer
• Characteristics:
  • High-speed operation
  • Low power consumption
  • Wide operating voltage range
  • Multiple package options
• Package: SOIC (Small Outline Integrated Circuit)
• Essence: The SN74LS257BNSR is a quad 2-input multiplexer with 3-state outputs.
• Packaging/Quantity: Tape and Reel, 2500 units per reel

Specifications

• Supply Voltage Range: 4.75V to 5.25V
• Input Voltage Range: 0V to VCC
• Output Voltage Range: 0V to VCC
• Operating Temperature Range: -40°C to +85°C
• Propagation Delay Time: 9ns (typical)
• Output Current: ±8mA
• Power Dissipation: 500mW (max)

Detailed Pin Configuration

The SN74LS257BNSR has a total of 16 pins, which are assigned as follows:

1. A0: Input A0
2. B0: Input B0
3. Y0: Output Y0
4. G1: Enable Input G1
5. A1: Input A1
6. B1: Input B1
7. Y1: Output Y1
8. G2: Enable Input G2
9. Y2: Output Y2
10. A2: Input A2
11. B2: Input B2
12. Y3: Output Y3
13. G3: Enable Input G3
14. VCC: Positive Power Supply
15. GND: Ground
16. NC: No Connection

Functional Features

• Quad 2-input multiplexer with 3-state outputs
• Allows selection of one out of four data inputs
• 3-state outputs provide high impedance when disabled
• Enable inputs control the operation of each multiplexer

Advantages and Disadvantages

Advantages: - High-speed operation allows for efficient data selection - Low power consumption helps in reducing energy usage - Wide operating voltage range ensures compatibility with various systems - Multiple package options provide flexibility in design and integration

Disadvantages: - Limited to 2-input multiplexing, not suitable for applications requiring more inputs - Propagation delay time may affect real-time applications with strict timing requirements

Working Principles

The SN74LS257BNSR is a digital multiplexer that selects one of the four input signals based on the control inputs. The enable inputs (G1, G2, G3) determine which multiplexer is active. When an enable input is low, the corresponding multiplexer is disabled, and its output is in a high-impedance state.

The selected input is then routed to the respective output pin (Y0, Y1, Y2, Y3). The device operates on a supply voltage between 4.75V and 5.25V, and the output current is limited to ±8mA.

Detailed Application Field Plans

The SN74LS257BNSR can be used in various applications, including:

1. Data routing and selection in digital systems
2. Address decoding in memory systems
3. Signal switching in communication systems
4. Input/output expansion in microcontrollers
5. Multiplexing control signals in industrial automation

Detailed and Complete Alternative Models

1. CD4051B: 8-channel analog multiplexer/demultiplexer
2. MC14051B: 8-channel analog multiplexer/demultiplexer
3. 74HC151: 8-to-1 multiplexer
4. 74HC153: Dual 4-to-1 multiplexer
5. CD4052B: Dual 4-channel analog multiplexer/demultiplexer

These alternative models offer similar functionality and can be considered as substitutes for the SN74LS257BNSR in different applications.

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