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TXB0304: TXB0304 power question

Ranita Bera
Prodigy 610 points
Part Number: TXB0304
Other Parts Discussed in Thread: LSF0204, SN74LVC2T45, SN74LV1T125, SN74AUP1T34

My customer has identified a potential benefit to using, TXB0304, a 4-bit level translator in their new design.

The TXB0304 fits all their desired features, but the power numbers aren't entirely clear to them. In high impedance mode, it says each supply could draw a max of 5uA when in high impedance mode, but doesn't give a typical value for that. Is there anyone who could give more detail about the power consumption of this level translator, or is there another level translator that meets these requirements. 

Key features they need:

1) Automatic bi-directional support in push-pull (using for SPI). Alternatively, 2 bits can be locked to one direction, and 2 bits locked to the other.

2) Ability to convert between 1.8V on the low side and anywhere from 2-3V on the high side.

3) Very small (preferably < 2mm x 2mm)

4) Low power when not in use (preferably < 1uA)


Would you please help provide clarification about the power (or tips for how to use it at very low idle power), and any recommendations for other level translators that fit the requirements above?

 

  • 0
    TI__Mastermind 30105 points
    Hello Ranita,

    We do not have a translator that will be guaranteed to consume less that 1uA total when idle. Based on your requirements, the TXB0304 is the best choice for your application in terms of minimum power consumption and small form factor. We do not publish the typical values for current consumption because they can vary greatly depending on operating conditions, manufacturer process, etc. Instead, we publish the maximum values which allows us to provide a guarantee to our customers that the device will operate within these specifications.

    When in an idle state, to minimize power consumption we should pull OE to GND to disable the IO. This will ensure that the IO ports will consume <1uA each when operating at ambient temperature. The supplies can consume a maximum of 5uA each, even when the IO is disabled. This puts the total possible current consumption at over 10uA when in idle state. Unfortunately, we do not have any translators that meet your requirements that we can guarantee will consume less that 10uA, and definitely not less than 1uA.
  • 0 in reply to aozer
    TI__Prodigy 590 points
    Based on those numbers it doesn't look like it will be a viable option . The target current for the whole device in deep sleep is <10 uA.
  • 0
    TI__Mastermind 26335 points
    Hello Ranita,

    Perhaps your customer may also consider the LSF0204 as it is bidirectional, can be used with a push-pull driver to the IO, draws max +-1uA when the power supplies are off, and can be used in a relatively small package (DSBGA: 1.9mmx1.4mm).

    However I would like to clarify one part of your question though. When you say low power when not in use, are you meaning that it would be in sleep mode where the supplies are still high and only the enable is low, or completely off as is the supplies and enable are all low?
  • 0 in reply to Patrick Simmons
    TI__Prodigy 590 points
    Patrick,

    The power numbers look great, but the only concern is that it appears to require a minimum of 2.5V on one side to convert to 1.8V on the other.

    Since the battery goes from 3V at full to 2V at empty, it doesn't seem like it would work for the whole range of the battery.
    Maybe you can confirm or refute that notion?
  • 0 in reply to EEngineer505
    TI__Mastermind 26335 points
    Hello EEngineer505,

    I want to clarify which part you are referring to. Are you talking about the TXB0304 posted at the beginning of the thread or the alternative (LSF0204) I suggested in my response? From the datasheets 2V falls in the recommended operating range on both A or B sides of either part.
  • 0 in reply to Patrick Simmons
    TI__Prodigy 590 points
    Sorry for confusion.

    I am referring to LSF0204
  • 0
    Guru 316780 points
    SN74LVC2T45 has worst-case values of 2 µA (depending on what "not in use" means).
    4× SN74AUP1T34 or SN74LV1T125 also look as if they might work.

    Typically, leakage current is temperature dependent. Is there information about the actual temperature range?