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TPS65132: Can transient current (peak current) be supplied?

Kaji@PAN
Mastermind 7015 points
Part Number: TPS65132
Other Parts Discussed in Thread: , TPS65131, TPS65130

Hi,

I am considering using TPS65132 devices.
The specification is below.
The load is liquid crystal. We constantly supply 20mA by TPS65132.
However, 160mA flows transiently.
I thought that TPS65132 could not satisfy my specifications, but I found the following description in the data sheet.
According to this contents, it seems that the output peak current can be adjusted by the output capacitor.
Since the output voltage on the plus side can be supplied up to 200mA, we believe there is no problem.

I want to ask two questions.
(1) If the current that the minus side output voltage can supply is 80 mA, will the current limit function operate even if transient 160 mA flows? In this case, will the operation stop?
(2) Can transient current (peak current) be supplied by the output capacitor as shown in the data sheet?
    In other words, if it is possible to supply from a capacitor even if 160 mA flows momentarily, is it possible to prevent the overcurrent detection function from operating?

(specification)
VIN : 5 V (min 4V)
VOUT : +5.5V / 20mA, -5.5V / 20mA
It is necessary to separately control EN by plus voltage and minus voltage.

Best Regards,

  • 0
    TI__Intellectual 2805 points
    Hello Kaji-san

    Which version of the TPS65132 are you using? The output capacitor could supply this additional current but only for a short time. If the transient is too long, then the negative rail will be out of regulation or even shut down. How long does the transient last and at what frequency (approximately)?
    From your last sentence, I assume you don't want to use the TPS65132S. Am I right?

    Best regards,
    Diaara
  • 0 in reply to Diaara
    Mastermind 7015 points

    Thank you for your reply.
    I got additional information on the rush current occurring on the output side.
    The occurrence period is 1ms.
    So the output current is steadily 20mA, but it is assumed that 160mA will flow for 1ms.

    Is it possible to supply the above rush current from the output capacitor at the negative side output of TPS65132?
    In this case, does overcurrent detection work?

    (Other information)
    I would like to select TPS65132Ax,Bx,Lx,Tx because I want to perform different EN control with positive and negative power supply.
    The output current of the TPS65131 is large, but in my application I would like to downsize it, so I would like to select a device with a smaller package size.

    Best Regards,

  • 0 in reply to Kaji@PAN
    TI__Intellectual 2805 points
    Hello Kaji-san,

    It is not possible to support this additional current for that long. Only the TPS65132S version would be able to but it does not have separate enable pins like you want. BTW, is this separate enable control a must?
    The next solution is the TPS65130/TPS65131 as you mentioned which has a bigger footprint.

    Best regards,
    Diaara
  • 0 in reply to Diaara
    Mastermind 7015 points
    Thank you for your reply.
    Individual control of EN is absolutely necessary.