Automotive 5-V, 2:1 (SPDT), 4-channel switch with 1.8-V logic and powered-off protection


Product details


Configuration 2:1 SPDT Number of channels (#) 4 Power supply voltage - single (V) 1.8, 2.5, 3.3 Ron (Typ) (Ohms) 2 ON-state leakage current (Max) (µA) 0.9 Bandwidth (MHz) 1200 Operating temperature range (C) -40 to 125 Features 1.8-V compatible control inputs, Break-before-make, Fail-safe logic, Integrated pulldown resistor on logic pin, Powered-off protection, Supports SPI signals, Supports input voltage beyond supply TI functional safety category Functional Safety-Capable Input/output continuous current (Max) (mA) 25 Rating Automotive, Catalog CON (Typ) (pF) 8 Supply current (Typ) (uA) 7.5 open-in-new Find other Analog switches & muxes

Package | Pins | Size

SOT-23-THN (DYY) 16 8 mm² 4.2 x 2 TSSOP (PW) 16 22 mm² 5 x 4.4 open-in-new Find other Analog switches & muxes


  • AEC-Q100 qualified for automotive application
    • Temperature grade 1: -40°C to +125°C, TA
  • Wide supply range: 1.5 V to 5.5 V
  • Low propagation delay: 78 ps
  • Low on-resistance: 5 Ω
  • High bandwidth: 1.2 GHz
  • Bidirectional Signal Path
  • Supports Input Voltage Beyond Supply
  • 1.8 V Logic Compatible
  • Integrated Pull Down Resistor on Logic Pins
  • Fail-Safe Logic
  • Powered-off Protection up to 3.6 V Signals
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The SN3257-Q1 is an automotive grade complementary metal-oxide semiconductor (CMOS) switch that supports high speed signals with low propagation delay. The SN3257-Q1 offers a 2:1 (SPDT) switch configuration with 4-channels making it ideal for multi-lane protocols such as SPI and I2S. The device supports bidirectional analog and digital signals on the source (SxA, SxB) and drain (Dx) pins and can pass signals above supply up to VDD x 2, with a maximum input and output voltage of 5.5 V.

The SN3257-Q1 has an active low EN pin that is used to enable and disable all channels simultaneously. When the EN pin is LOW, one of the two switch paths is selected based on the state of SEL pin.

Powered-off protection up to 3.6 V on the signal path of the SN3257-Q1 provides isolation when the supply voltage is removed (VDD = 0 V). Without this protection feature, switches can back-power the supply rail through an internal ESD diode and cause potential damage to the system.

Fail-safe logic circuitry allows voltages on the logic control pins to be applied before the supply pin, protecting the device from potential damage. Both logic control inputs have 1.8 V logic compatible thresholds, ensuring both TTL and CMOS logic compatibility. Integrated pull down resistor on the logic pins removes external components to reduce system size and cost.

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Technical documentation

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Type Title Date
* Data sheet SN3257-Q1 5-V, Low Propagation Delay, 2:1 (SPDT), 4-Channel Switch with 1.8 V Logic datasheet (Rev. B) Jan. 30, 2020
Application note Multiplexers and Signal Switches Glossary (Rev. A) Jun. 09, 2021
Application note 1.8 V Logic for Muxes and Signal (Rev. A) Jan. 06, 2021
Application note Eliminate Power Sequencing with Powered-off Protection Signal Switches (Rev. C) Jan. 06, 2021
Application note Enabling SPI-Based Flash Memory Expansion by Using Multiplexers (Rev. A) Jan. 06, 2021
Technical article Overcome last-minute requirement changes with SOT-23 multiplexers Sep. 18, 2020
Application note Selecting the Right Texas Instruments Signal Switch (Rev. B) Apr. 02, 2020
Functional safety information SN3257-Q1 Functional Safety FIT Rate, FMD and Pin FMA Feb. 18, 2020
User guide 16DYYPWEVM Test board for SOT-23 THIN (DYY) and TSSOP (PW) packages User's Guide Nov. 11, 2019
Technical article Roll with the design punches and overcome power-sequencing challenges Jul. 29, 2019

Design & development

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

Hardware development

document-generic User guide
The 16DYYPWEVM test board provides a dual footprint for SOT-23 THIN (DYY) and TSSOP (PW) packages.  This test board is used for quick prototyping and testing of integrated ciructs in 16 pin SOT-23 THIN (DYY) and TSSOP (PW) packages. 
  • Dual footprint of  SOT-23 THIN (DYY) and TSSOP (PW) packages
  • Quick prototyping and testing of 16 pin IC in SOT-23 THIN (DYY) and TSSOP (PW) packages
  • All 16 signals paths include 0603 pads for pull-up, pull-down, or load-capacitors
  • Test site with 3 SMB connectors for high speed evalauation for TMUX1574 (...)
document-generic User guide

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.     

  • Quick testing of TI's leaded surface mount packages 
  • Allows leaded suface mount packages to be plugged into 100mil spaced bread board 
  • Supports TI's 8 most popular leaded packages with a single panel

Design tools & simulation

SCDM234.ZIP (11 KB) - IBIS Model

CAD/CAE symbols

Package Pins Download
SOT-23-THN (DYY) 16 View options
TSSOP (PW) 16 View options

Ordering & quality

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