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TPS22965: TPS22965 Larger CL capacitor value

ZHIYAR TAHIR
Prodigy 30 points
Part Number: TPS22965
Other Parts Discussed in Thread: TPS22953

Tool/software:

Hello TI Experts, 

Section 10.1.3 of the TPS22965 datasheet indicates that a Cin greater than CL is highly recommended due to the current flow through the body diode from Vout to Vin. In my design, the CL is 330 uF, Cin is 1 uF also CT is 1 nF. The Input is 5V, and the maximum current is 3A. How much reverse current can TPS22965 handle? Will damage occur to the chip due to reverse current ?

ZHIYAR TAHIR

  • 0
    TI__Mastermind 36861 points

    Hello Zhiyar,

    Sorry for the delay.

    Is the output cap placed close to load switch?

    Can you share the block diagram?

    TPS22965 has QOD which will help in discharging the VOUT. Device can handle reverse current of rated load current (6A) for 10 uSec time.

    Thanks

    Amrit 

  • 0 in reply to Amrit Jit
    Prodigy 30 points

    Hello Amrit,

    I appreciate your response.

    Actually, there is (1uF 0805 X7R 25 VDC (C1)) near the input pin and (0.1UF 0805 X7R 25 VDC (C2)) near the output pin. The 330uF (C3) is not far or so close to the chip, it locate near to the next chip (LDO).

    Unfortunately, Usually there is a power outage. So the ON pin may not always be switched off (Asserting ON pin LOW) by the user. I am not sure if QOD could discharge the capacitor during a power supply outage since the ON is Asserted HIGH during power outage!

    Please take a look at the attached image.

    ZHIYAR TAHIR

  • 0 in reply to ZHIYAR TAHIR
    TI__Mastermind 36861 points

    Hello Zhiyar,

    I would recommend to opt load switch which has reverse current blocking if the project is in design phase.

    Let me know your system requirement for me to recommend.

    Thanks 

    Amrit 

  • 0 in reply to Amrit Jit
    Prodigy 30 points

    Hi Amrit,

    Sorry for the late reply — it’s been a really busy week.

    The system requires a 5V supply with a current capacity of 3A.

    Thank you for all the information. I’m considering adding a diode to the output pin to prevent reverse current flow. It seems like a simpler and more cost-effective solution. Also does not need to replace the IC.

    Let me know what you think!

    Best regards,
    Zhiyar Tahir

  • +1 in reply to ZHIYAR TAHIR
    TI__Mastermind 36861 points

    Hello Zhiyar

    You can check TPS22953 which has RCB when disabled. 

    Suitable for your application with higher COUT value than CIN.

    Adding a diode can result in voltage drop. Diode will also work.