SCES008Q July   1995  – September 2018 SN54LVCH245A , SN74LVCH245A

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
    2.     Pin Assignments: ZQN Package
    3.     Pin Assignments: ZXY Package
  6. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  Recommended Operating Conditions: SN74LVCH245A
    4. 6.4  Recommended Operating Conditions: SN54LVCH245A
    5. 6.5  Thermal Information
    6. 6.6  Electrical Characteristics: SN74LVCH245A
    7. 6.7  Electrical Characteristics: SN54LVCH245A
    8. 6.8  Switching Characteristics: SN74LVCH245A, –40°C TO 85°C
    9. 6.9  Switching Characteristics: SN74LVCH245A, –40°C TO 125°C
    10. 6.10 Switching Characteristics: SN54LVCH245A
    11. 6.11 Operating Characteristics
    12. 6.12 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Balanced High-Drive CMOS Push-Pull Outputs
      2. 8.3.2 Standard CMOS Inputs
      3. 8.3.3 Negative Clamping Diodes
      4. 8.3.4 Bus-Hold Data Inputs
      5. 8.3.5 Partial Power Down (Ioff)
      6. 8.3.6 Over-voltage Tolerant Inputs
      7. 8.3.7 Output Enable
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Related Links
    2. 12.2 Trademarks
    3. 12.3 Electrostatic Discharge Caution
    4. 12.4 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • DGV|20
  • DB|20
  • NS|20
  • DW|20
  • PW|20
  • RGY|20
Thermal pad, mechanical data (Package|Pins)
Orderable Information

9.1 Application Information

The SN74LVCH245A device is a high-drive CMOS device with bus-hold inputs that can be used for a multitude of bus interface type applications where the data needs to be transmitted and received. The device's output can produce 24 mA of drive current at 3.3 V. Therefore, this device is ideal for driving multiple outputs and for high-speed applications up to 100 MHz. The inputs are 5.5-V tolerant which allows the devices to translate down to VCC.

Figure 10 shows a typical down-translation application in which the device is being used with a fixed direction to reduce an 8-bit 5-V bus to an 8-bit 1.8-V bus.

Figure 11 shows a typical application in which a bus must switch directions for data transfer between a master and a slave device. The SN74LVCH245A allows either VCC1 or VCC3 to be shut down completely because it has bus-hold inputs that maintains valid states on the floating lines. In this example, VCC1, VCC2, and VCC3 all have the same value, but each supply can be delivered by a separate source.

Figure 12 shows a functional diagram for a single channel of the device, including the bus-hold, direction, and output enable logic components. When the direction is set as 'A to B,' the buffer labeled 'A' is disabled and the buffer labeled 'B' is enabled. When the direction is set as 'B to A,' the buffer labeled 'B' is disabled and the buffer labeled 'A' is enabled. When the output enable pin is deasserted, the buffers labeled 'A' and 'B' are both disabled. The bus-hold circuitry remains active at all times.