SCDS145D October   2003  – August 2026 SN74CB3Q3253

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 Electrical Characteristics: RGY, PW, DBQ, DGV Packages
    6. 5.6 Electrical Characteristics: DYY Package
    7. 5.7 Switching Characteristics: RGY, PW, DBQ, DGV Packages
    8. 5.8 Switching Characteristics: DYY Package
    9. 5.9 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 Curve
    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. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

7.1 Overview

The SN74CB3Q3253 device is a high-bandwidth FET bus switch using a charge pump to elevate the gate voltage of the pass transistor, providing a low and flat ON-state resistance (ron). The low and flat ON-state resistance allows for minimal propagation delay and supports rail-to-rail switching on the data input/output (I/O) ports. The device also features low data I/O capacitance to minimize capacitive loading and signal distortion on the data bus. Specifically designed to support high-bandwidth applications, the SN74CB3Q3253 device provides an optimized interface design designed for broadband communications, networking, and data-intensive computing systems.

The SN74CB3Q3253 device is organized as two 1-of-4 multiplexers/demultiplexers with separate output-enable (1 OE, 2 OE) inputs. The select (S0, S1) inputs control the data path of each multiplexer/demultiplexer. When OE is low, the associated multiplexer/demultiplexer is enabled, and the A port is connected to the B port, allowing bidirectional data flow between ports. When OE is high, the associated multiplexer/demultiplexer is disabled, and a high-impedance state exists between the A and B ports.

This device is fully specified for partial-power-down applications using Ioff. The Ioff circuitry prevents damaging current backflow through the device when powered down. The device has isolation during power off.

To maintain the high-impedance state during power up or power down, OE must be tied to VCC through a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.

SN74CB3Q3253 Simplified Schematic, Each FET Switch (SW)
EN is the internal enable signal applied to the switch.
Figure 7-1 Simplified Schematic, Each FET Switch (SW)