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Original question:

LP87561-Q1: Current Limit Functionality Doubt

LP87561-Q1: LP87561-Q1 same function

Kevin Huang67
Intellectual 370 points
Part Number: LP87561-Q1
Other Parts Discussed in Thread: LP8764-Q1, LP8758-B0, LP8758

Hi sir,

The LP87561 is out of stock, can you recommend the 16A PMIC that it has differential sense from C load to use?

  • 0
    TI__Genius 11020 points

    Hello Kevin,

    For automotive system only device I could think of is LP8764-Q1 which is still under development. For non-automotive LP8758-B0 could be one alternative. 

    Thanks.

    Regards,

    Tomi Koskela

  • 0 in reply to Tomi Koskela
    Intellectual 370 points

    Hi Tomi,

    Can LP8758-B0 be disabled the power remote sense function and work as general switching regulator ?

  • 0 in reply to Kevin Huang67
    TI__Genius 11020 points

    Hi Kevin,

    I'm not quite sure did I understand the question correctly. Anyway the FB pin must be connected to the output voltage. At what point at the output net the FBs are connected depends on what point do you need to have accurate voltage regulation. 

    Thanks.

    Regards,

    Tomi Koskela

  • 0 in reply to Tomi Koskela
    Intellectual 370 points

    Hi Tomi,

    1. Can I disable the remote sense function(FB_B0, FB_B1) of LP8758 by register ?

    2. Are the FB_B0,FB_B1 differential pairs from C load to have length limitation and impedance 

        value(such as 100 ohm...)?

    3. The C out+C load <= 200uF in the datasheet.

        Are the C load 100uF to be suitable for 16A load ?

        If the C load is 300uF, will the PMIC be abnormal ?

  • 0 in reply to Kevin Huang67
    TI__Genius 11020 points

    Hello Kevin,

    1. There is no registers to change the feedback. It is matter of where do you route the FBs in the PCB. Anyway you need to have feedback(s) connected to the buck output, device cannot operate if it does not sense the output voltage.

    2. No such limitations since the FBs are high impedance inputs and it is not that sensitive. Just avoid routing close to noisy signals and keep the traces close to each other to avoid creating a big loop antenna. 

    3. 100uF can be used with 16A load, as long as it is with datasheet limits. Higher output capacitance usually yields higher phase margin/stability. It is not recommended to exceed the specified 200uF limit since it can trigger current limit during startup/shutdown or voltage change, depending on set slew rate setting.

    Thanks.

    Regards,

    Tomi Koskela