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TS3L301: Unused pins.

Harsh b
Intellectual 430 points
Part Number: TS3L301

What we should for unused IO pins of this ic?

  • 0
    TI__Mastermind 46607 points

    Hi Harsh,

    All ground and VDD connections must be used.

    All A and B pins can be terminated with 50 Ohm resistor to ground if not used. Leaving them floating can cause signal integrity issues at high frequency.

    If a select pin is unused it must be tied to ground or VDD through a pull-up resistor so that a defined logic state is always present.

    No Connect pins can be left unconnected .

    Please see the video on unused pins from TI Precision Labs Here.

    Best Regards,

    Parker Dodson

  • 0 in reply to Parker Dodson
    Intellectual 430 points

    We use this IC for selecting SPI interface for two different devices,

    and we operate at 1 MHz of fclk. 

    As this frequency is very low 

    1). Do we still need 50E resistor connected to ground for A and B pins?

    2). As this IC's Bandwidth is too high i,e. 900MHz, will this has any issue's like picking unwanted noise?

  • 0 in reply to Harsh b
    TI__Mastermind 46607 points

    Hi Harsh,

    1. At 1MHz you shouldn't run into any problems by leaving signal paths open if they aren't used, the A/B pins.

    2 The Mux doesn't really act as an antenna, and it's bandwidth is also highly dependent on the load, i.e. a high capacitive load will have a lower bandwidth. However if there are other noise sources in the system that send a noise signal through the switch, the switch will typically not degrade signal content below the bandwidth much, but it most likely will not be picking up noise and injecting the noise signal into the switch. 

    Best,

    Parker Dodson