• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 62 subscribers
  • Views 392 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LM53602-Q1: Iq at light loads

Jared Becker
Genius 11515 points
Part Number: LM53602-Q1

Hi Team,

I am trying to understand the supply current value during light load conditions for the LM53602-Q1. I have a real time clock that only needs a few uA of current, and needs to have a regulated voltage supplied by the LM53602-Q1. In the datasheet, the Isupply parameter is specified under a condition when there is 0 A of current draw:

I understand the details of this formula as below:

What is the impact to this number/this formula if there is a small load current of a few uA?

Looking forward to your input.

Jared

  • 0
    TI__Expert 4100 points

    Hi Jared,

    The contribution of output current to the overall input current will depend of duty ratio (Vout/Vin), and conversion efficiency.

    The approximation could be made as follows: Iin = (duty cycle * Iout)/conversion efficiency.

    For light load convesrion efficiency could be approximated to be ~80% (0.8).

    With these assumptions: Iout~10uA , D=0.5, Eff = 0.8 it results in input current increase of 6.25uA.

    This practically means that measured input current will increase for 6.25uA compared to no load conditions.

    I hope this helps.

    Best regards

    Brani

  • 0 in reply to Brani Dubocanin
    TI__Genius 11515 points

    Hi Brani,

    I understand this to mean that there is no impact to the current draw by the IC itself, is that correct?

    Here is what I am understanding from what you said:

    Vin = 10V, Iin = 6.25uA ====> ~34uA consumed by IC =====> Vout = 5V, Iout = 10uA

    Total current consumption = 6.25uA + 34uA

    or another example:

    Vin = 10V, Iin = 62.5mA =====> ~34uA consumed by IC =====> Vout = 5V, Iout = 100mA

    Total current consumption = 62.5mA + 34uA

    Is my understanding correct?

    Thanks!

    Jared

  • 0 in reply to Jared Becker
    TI__Expert 4100 points

    Hi Jared,

    You are correct.

    In essence this is close approximation of current drawn by the IC.

    Best regards

    Brani