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SN74AVC4T245: Asking for the SN74AVC4T245PW I2S support

SHH
Mastermind 30301 points
Part Number: SN74AVC4T245
Other Parts Discussed in Thread: SN74LV4T125, TXB0104,

Hi Team,
Customer would like to know whether they can use SN74AVC4T245PW for the audio I2S level shifht from 1.8V to 3.3V?

Can you help check this?

I2S has MCLK,BCLK, WCLK and Data line.
The highest speed may aceieve 24MHz.


Thanks,
SHH

  • 0
    Guru 243870 points
    Yes; I²S uses plain CMOS signals, and the datasheet says that 1.8V-to-3.3V translation supports up to 380 Mbps.

    (I²S is unidirectional, with all four signals in the same direction, so a unidirectional level shifter such as the SN74LV4T125 works, too. But in this case, it would probably use more power than the AVC4T245.)
  • 0 in reply to Clemens Ladisch
    TI__Mastermind 30301 points

    Hi Clemens,
    Thanks for reply.

    Could you help for the following questions?
    1. Why LV4T125 use more power than the AVC4T245?
    2. which 1.8V>3.3V level shifter device we would suggest?
    3. for TXB0104 and SN74XXX unidirection, which one is more fit for I2S 1.8V>3.3V level shifter applicaiton?

    Thanks,
    SHH

  • 0 in reply to SHH
    Guru 243870 points

    The LV4T125 has only a single power supply; it allows uptranslation by having lower input thresholds. This implies that a 1.8 V signal only partially turns on the input transistors; see the FAQ.

    The TXB has automatic direction sensing; as a consequence of that, it needs high drive strength in the device driving it, and its own outputs have low drive strength. However, this should not be a problem for I²S signals.

    All three devices would work. Choose by price, and/or size, and/or power usage.

  • 0 in reply to SHH
    TI__Guru 56070 points
    Thank you , Clemens for your reply .
    SHH ,
    LV4T125 is a single supply unidirectional level shifter. With 3.3Vcc and input at 1.8V , there is higher Icc current consumed than the quiescent current. You could consider the SN74AVC4T245 with dual supply which helps in lowering the current consumption of the system.
  • 0 in reply to ShreyasRao
    TI__Mastermind 30301 points
    Hi Shreyas and Clemens,
    Thanks for your valuable input.

    Thansk,
    SHH