SCDS149B October   2003  – December 2025 SN74CB3T3257

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Recommended Operating Conditions
    6. 5.6 Electrical Characteristics
    7. 5.7 Switching Characteristics 85C
    8. 5.8 Typical Characteristics
  7. 6 Parameter Measurement Information
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
    4. 7.4 Device Functional Modes
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Performance Plots
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1.      Related Documentation
      2. 9.1.1 Receiving Notification of Documentation Updates
      3. 9.1.2 Support Resources
      4. 9.1.3 Electrostatic Discharge Caution
      5. 9.1.4 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

3 Description

The SN74CB3T3257 is a high-speed TTL-compatible FET multiplexer/demultiplexer with low ON-state resistance (ron), allowing for minimal propagation delay. The device fully supports mixed-mode signal operation on all data I/O ports by providing voltage translation that tracks VCC. The SN74CB3T3257 supports systems using 5V TTL, 3.3V LVTTL, and 2.5V CMOS switching standards, as well as user-defined switching levels.

This device is fully specified for partial-power-down applications using Ioff. The Ioff feature verifies that damaging current does not backflow through the device when the device is powered down. The device has isolation during power off.

Package Information
PART NUMBERPACKAGE (1)PACKAGE SIZE(2)
SN74CB3T3257PWPW (TSSOP, 16)5.00mm × 6.40mm
SN74CB3T3257DGVDGV (TVSOP, 16)3.60mm × 6.40mm
SN74CB3T3257DYYDYY (SOT, 16)4.20mm × 2.0mm
(1) For more information, Section 11.
(2) The package size (length x width) is a nominal value and includes pins, where applicable.
Device Information
INPUTSINPUT/OUTPUT AFUNCTION
OES
LLB1A port = B1 port
LHB2A port = B2 port
HXZDisconnect
SN74CB3T3257 Typical DC Voltage Translation Characteristics Typical DC Voltage Translation Characteristics