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TCAN4550: Power consumption based on different VSUP

Part Number: TCAN4550

Hi Team,

How should we compare power consumption between different VSUP?

For example, is the power consumption of 12VSUP two times of 6VSUP?

Regards,

 

  • Hi Charles,

    The VSUP for TCAN4550 supplies an integrated LDO that will consume the majority of the current through VSUP. Fundamentally, LDOs are most efficient when the input voltage and output voltage are as close as possible, so naturally we expect the least overall power consumption to occur when VSUP is closest to to output voltage of 5V (recommended 6V minimum due to LDO dropout and losses). 

    To address your questions of how power consumption increases with supply voltage, let's generalized and ignore non-LDO current loads and assume an ideal LDO with no ground current. In this case, all current supplied to the LDO's load is sourced from the VSUP supply. This means that the same 100mA load will draw 100mA from VSUP whether the input voltage is 6V or 12V. In a real application, other factors will also play into this relationship, but the power consumption-supply voltage relation will remain roughly linear in this way.

    Let me know if this makes sense and if you have any more questions.

    Regards,
    Eric Schott