Texas Instruments SN3257-Q1 2:1 SPDT 4-Ch CMOS Switch
Texas Instruments SN3257-Q1 2:1 SPDT 4-Ch CMOS Switch supports high-speed signals with low propagation delay. It offers a 2:1 (SPDT) switch configuration with four 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. The SN3257-Q1 can pass signals above supply up to VDD x 2, with a maximum input and output voltage of 5.5V.
The SN3257-Q1 has an active-low EN pin 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 the SEL pin. Powered-off protection up to 3.6V on the signal path of the SN3257-Q1 provides isolation when the supply voltage is removed (VDD = 0V). Without this protection feature, switches can back-power the supply rail through an internal ESD diode and cause potential damage to the system.
The SN3257-Q1 is protected from potential damage by fail-safe logic circuitry that allows voltages on the logic control pins to be applied before the supply pin. TTL and CMOS logic compatibility is ensured via logic control inputs with 1.8V logic-compatible thresholds. An integrated pull-down resistor on the logic pins removes external components to reduce system size and cost.
The Texas Instruments SN3257-Q1 devices are AEC-Q100 qualified for automotive applications.
Features
- AEC-Q100 qualified for automotive application
- Temperature grade 1 (-40°C to +125°C, TA)
- 1.5V to 5.5V wide supply range
- 78ps low propagation delay
- 5Ω low on-resistance
- 1.2GHz high bandwidth
- Bidirectional signal path
- Supports input voltage beyond supply
- 1.8V logic compatible
- Integrated pull-down resistor on logic pins
- Fail-safe logic
- Powered-off protection up to 3.6V signals
Applications
- SPI multiplexing
- I2S multiplexing
- eSIM multiplexing
- eMMC multiplexing
- Flash memory sharing
- Battery Management System (BMS)
- Telematics Control Unit (TCU)
- Smart telematics gateway
- Rear seat entertainment
- Digital cockpit processing unit
- Automotive head unit
- Automotive navigation
- ADAS domain controller
- Surround-view system ECU
- On-board (OBC) and wireless charger
Application Example
Functional Diagram
Related Development Tool
Texas Instruments 16DYYPWEVM Test Board
Provides a dual footprint for SOT-23 THIN (DYY) and TSSOP (PW) packages.