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Original question:

PGA460: UART -> ¿Level Shifter?

TXS0102: UART level-shifter than can accommodate both "VCCA ≤ VCCB" and "VCCA ≥ VCCB"

Blindu Marcel
Intellectual 325 points
Part Number: TXS0102
Other Parts Discussed in Thread: SN74LVC2T45, SN74AVC4T245, TXB0302, PGA460

We need a UART level-shifter than can accommodate both "VCCA ≤ VCCB" and "VCCA ≥ VCCB".

Somebody know any level shifter that meets the above conditions?

  • 0
    TI__Guru 62560 points
    Hi Blindu,

    TXS0102 have the restrictions on the Vcca power supply to not exceed Vccb. ( Vcca<=Vccb. )
    Please let me know the voltage levels for translation. There are DIR controlled translators SN74AVC4T245(up to 3.6V ) or the SN74LVC2T45(up to 5.5V) which supports UART and doesnt have restriction on the power supply voltages.
    Please let me know.
  • 0 in reply to ShreyasRao
    Intellectual 325 points
    Vcca=3.0V or 3.6V and Vccb=3.3V.
    How about using the level shifter "TXB0302" for the uart level traslator?
  • 0 in reply to Blindu Marcel
    TI__Guru* 97066 points
    Hi Blindu,
    It doesn't seem like a translator is needed for that application -- many 3.3V supplies can vary from 3 to 3.6V, and usually the inputs to devices support +/- 0.5V safely for VIH. Can you describe your system or post a schematic?
  • 0 in reply to Emrys Maier
    Intellectual 325 points
    The system is the following:

    1. Microcontroller -> Power with battery (3.0V or 3.6V). The voltage can fluctuate depend of the capacity of the battery (↓3.0V). (Uart Level -Battery Level)
    2. Ultrasonic Signal Processor -> (Battery (3.0V or 3.6V) - Boost (7.5V) - PGA460). (Uart Level -3.3V (IOREG pin))

    Therefore depending on the battery we use the level of the UART of the microcontroller will be higher than of the PGA and others lower.
  • 0 in reply to Blindu Marcel
    TI__Guru 62560 points
    Blindu,

    I believe that the voltage fluctuation is within the 10% range of the nominal level and hence level shifter may not be required in the application.
    Having said that your choice of TXB0302 have fully configurable voltage rails without any restrictions.