Home Switches & multiplexers Analog switches & muxes
Home
Switches & multiplexers
Analog switches & muxes

SN74CBT3257C

ACTIVE

5-V, 2:1 (SPDT), 4-channel FET bus switch with –2-V undershoot protection

Order now
Data sheet

SN74CBT3257C

ACTIVE
Data sheet Order now

Product details

Configuration 2:1 SPDT Number of channels 4 Power supply voltage - single (V) 5 Protocols Analog, I2C, I2S, JTAG, RGMII, SPI, TDM, UART Ron (typ) (Ω) 3 CON (typ) (pF) 16.5 Bandwidth (MHz) 200 Operating temperature range (°C) -40 to 85 Features Undershoot protection Input/output continuous current (max) (mA) 128 Rating Catalog Drain supply voltage (max) (V) 5.5 Supply voltage (max) (V) 5.5
Configuration 2:1 SPDT Number of channels 4 Power supply voltage - single (V) 5 Protocols Analog, I2C, I2S, JTAG, RGMII, SPI, TDM, UART Ron (typ) (Ω) 3 CON (typ) (pF) 16.5 Bandwidth (MHz) 200 Operating temperature range (°C) -40 to 85 Features Undershoot protection Input/output continuous current (max) (mA) 128 Rating Catalog Drain supply voltage (max) (V) 5.5 Supply voltage (max) (V) 5.5
SOIC (D) 16 59.4 mm² 9.9 x 6 SSOP (DB) 16 48.36 mm² 6.2 x 7.8 SSOP (DBQ) 16 29.4 mm² 4.9 x 6 TSSOP (PW) 16 32 mm² 5 x 6.4 VQFN (RGY) 16 14 mm² 4 x 3.5
  • Undershoot Protection for Off-Isolation on A and B Ports Up To .2 V
  • Bidirectional Data Flow, With Near-Zero Propagation Delay
  • Low ON-State Resistance (ron) Characteristics (ron = 3 Typical)
  • Low Input/Output Capacitance Minimizes Loading and Signal Distortion (Cio(OFF) = 5.5 pF Typical)
  • Data and Control Inputs Provide Undershoot Clamp Diodes
  • Low Power Consumption (ICC = 3 µA Max)
  • VCC Operating Range From 4 V to 5.5 V
  • Data I/Os Support 0 to 5-V Signaling Levels (0.8-V, 1.2-V, 1.5-V, 1.8-V, 2.5-V, 3.3-V, 5-V)
  • Control Inputs Can be Driven by TTL or 5-V/3.3-V CMOS Outputs
  • Ioff Supports Partial-Power-Down Mode Operation
  • Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II
  • ESD Performance Tested Per JESD 22
    • 2000-V Human-Body Model (A114-B, Class II)
    • 1000-V Charged-Device Model (C101)
  • Supports I2C Bus Expansion
  • Supports Both Digital and Analog Applications: USB Interface, Bus Isolation, Low-Distortion Signal Gating
  • Undershoot Protection for Off-Isolation on A and B Ports Up To .2 V
  • Bidirectional Data Flow, With Near-Zero Propagation Delay
  • Low ON-State Resistance (ron) Characteristics (ron = 3 Typical)
  • Low Input/Output Capacitance Minimizes Loading and Signal Distortion (Cio(OFF) = 5.5 pF Typical)
  • Data and Control Inputs Provide Undershoot Clamp Diodes
  • Low Power Consumption (ICC = 3 µA Max)
  • VCC Operating Range From 4 V to 5.5 V
  • Data I/Os Support 0 to 5-V Signaling Levels (0.8-V, 1.2-V, 1.5-V, 1.8-V, 2.5-V, 3.3-V, 5-V)
  • Control Inputs Can be Driven by TTL or 5-V/3.3-V CMOS Outputs
  • Ioff Supports Partial-Power-Down Mode Operation
  • Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II
  • ESD Performance Tested Per JESD 22
    • 2000-V Human-Body Model (A114-B, Class II)
    • 1000-V Charged-Device Model (C101)
  • Supports I2C Bus Expansion
  • Supports Both Digital and Analog Applications: USB Interface, Bus Isolation, Low-Distortion Signal Gating

The SN74CBT3257C is a high-speed TTL-compatible FET multiplexer/demultiplexer with low ON-state resistance (ron), allowing for minimal propagation delay. Active Undershoot-Protection Circuitry on the A and B ports of the SN74CBT3257C provides protection for undershoot up to –2 V by sensing an undershoot event and ensuring that the switch remains in the proper OFF state.

The SN74CBT3257C is a 4-bit 1-of-2 multiplexer/demultiplexer with a single output-enable (OE\) input. The select (S) input controls the data path of the multiplexer/demultiplexer. When OE\ is low, the 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 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 feature ensures that damaging current will not backflow through the device when it is powered down. The device has isolation during power off.

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

The SN74CBT3257C is a high-speed TTL-compatible FET multiplexer/demultiplexer with low ON-state resistance (ron), allowing for minimal propagation delay. Active Undershoot-Protection Circuitry on the A and B ports of the SN74CBT3257C provides protection for undershoot up to –2 V by sensing an undershoot event and ensuring that the switch remains in the proper OFF state.

The SN74CBT3257C is a 4-bit 1-of-2 multiplexer/demultiplexer with a single output-enable (OE\) input. The select (S) input controls the data path of the multiplexer/demultiplexer. When OE\ is low, the 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 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 feature ensures that damaging current will not backflow through the device when it is powered down. The device has isolation during power off.

To ensure the high-impedance state during power up or power down, OE\ should be tied to VCC through a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
filter Find other Analog switches & muxes
Download View video with transcript Video

Technical documentation

star =Top documentation for this product selected by TI
No results found. Please clear your search and try again.
View all 13
Type Title Date
* Data sheet SN74CBT3257C datasheet 06 Oct 2003
Application note Selecting the Correct Texas Instruments Signal Switch (Rev. E) PDF | HTML 02 Jun 2022
Application note Multiplexers and Signal Switches Glossary (Rev. B) PDF | HTML 01 Dec 2021
Application note CBT-C, CB3T, and CB3Q Signal-Switch Families (Rev. C) PDF | HTML 19 Nov 2021
Application brief Eliminate Power Sequencing with Powered-off Protection Signal Switches (Rev. C) PDF | HTML 06 Jan 2021
Selection guide Little Logic Guide 2018 (Rev. G) 06 Jul 2018
Selection guide Logic Guide (Rev. AB) 12 Jun 2017
Application note Understanding and Interpreting Standard-Logic Data Sheets (Rev. C) 02 Dec 2015
User guide LOGIC Pocket Data Book (Rev. B) 16 Jan 2007
More literature Digital Bus Switch Selection Guide (Rev. A) 10 Nov 2004
Application note Semiconductor Packing Material Electrostatic Discharge (ESD) Protection 08 Jul 2004
User guide Signal Switch Data Book (Rev. A) 14 Nov 2003
Application note Bus FET Switch Solutions for Live Insertion Applications 07 Feb 2003

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Interface adapter

LEADED-ADAPTER1 — Surface mount to DIP header adapter for quick testing of TI's 5, 8, 10, 16 & 24-pin leaded packages

The EVM-LEADED1 board allows for quick testing and bread boarding of TI's common leaded packages.  The board has footprints to convert TI's D, DBQ, DCT,DCU, DDF, DGS, DGV, and PW surface mount packages to 100mil DIP headers.     

User guide: PDF
Not available on TI.com
Interface adapter

LEADLESS-ADAPTER1 — Surface mount to DIP header adapter for testing of TI's 6,8,10,12,14,16, & 20-pin leadless packages

The EVM-LEADLESS1 board allows for quick testing and bread boarding of TI's common leadless packages.  The board has footprints to convert TI's DRC, DTP, DQE, RBW, RGY, RSE, RSV, RSW RTE, RTJ, RUK , RUC, RUG, RUM,RUT and YZP surface mount packages to 100mil DIP headers.
User guide: PDF
Not available on TI.com
Simulation model

SN74CBT3257C IBIS Model

SCDM035.ZIP (26 KB) - IBIS Model
Download
Package Pins CAD symbols, footprints & 3D models
SOIC (D) 16 Ultra Librarian
SSOP (DB) 16 Ultra Librarian
SSOP (DBQ) 16 Ultra Librarian
TSSOP (PW) 16 Ultra Librarian
VQFN (RGY) 16 Ultra Librarian
TI's Standard Terms and Conditions for Evaluation Items apply.

Ordering & quality

Information included:
  • RoHS
  • REACH
  • Device marking
  • Lead finish/Ball material
  • MSL rating/Peak reflow
  • MTBF/FIT estimates
  • Material content
  • Qualification summary
  • Ongoing reliability monitoring
Information included:
  • Fab location
  • Assembly location

Recommended products may have parameters, evaluation modules or reference designs related to this TI product.

Support & training

TI E2E™ forums with technical support from TI engineers

View all forum topics

Content is provided "as is" by TI and community contributors and does not constitute TI specifications. See terms of use.

If you have questions about quality, packaging or ordering TI products, see TI support. ​​​​​​​​​​​​​​

Videos