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DDC232: How to keep stable supply voltage for DDC232

Salvatore Maiorano
Prodigy 10 points
Part Number: DDC232
Other Parts Discussed in Thread: TPS3840,

Hello, I'm using a DDC232CK, which as you can see from the datasheet (page 4) needs a typical analog supply voltage of 5V. 
According to datasheet the maximum range allowed is between 4.9V and 5.1V and as they say at page 26, this voltage must stay as accurate as possible.

Is there a reference design for this or do you have any suggestion for this?
At the moment i was considering the idea of using a Voltage Supervisor like the TPS3840 or similar. 

Thank you

  • 0
    TI__Mastermind 19815 points

    Hi,

    Regarding to the voltage supervisor, a Voltage monitor/supervisor is not a power supply nor LDO, and it doesn't help to make the voltage rail cleaner, so it cannot be used to supply power to DDC232.

    But, you definitely can use a voltage supervisor if you need it for your application, but not for supplying voltage/power to the DDC232.

     

    You may search some LDO that can supply 5V and at least 360 or 400mW and meet the PSRR requirement specified in DDC232 datasheet - Power-Supply Rejection Ratio at DC  100 ±800  in unit of  ppm of FSR/V.

    And, take a look of REG1117-5.

    In the meantime, let me circle back to my team to see if we have better suggestion.

    Thanks

  • 0 in reply to ChienChun Yang
    Prodigy 10 points

    Sorry, my mistake cause the question was not really clear.

    I don't wanna use the Voltage Supervisor to supply the DDC232.
    I wanna supply the DDC with a normal power supply circuit (Like DDC, LDO etc..) and i wanna supply the Voltage supervisor with the same Voltage and after send the output of the voltage supervisor on the RESET pin of the DDC232 in order to reset it in case of a voltage drop.

    Is this actually possible? 
    Do you have any similar application? Or suggestion ab what voltage supervisor I can use?

    Thanks

  • 0 in reply to Salvatore Maiorano
    TI__Mastermind 19815 points

    Hi

    You may use a voltage supervisor the way you describe. But, from my point of view, some unstable and/or uncontrollable of reset pin may occur down to the road during developing/debugging/troubleshooting as if you only use/connect the voltage supervisor's output to the reset pin, then, what happen if you want to reset or if the voltage supervisor is malfunction? In these cases, you have no control to the reset pin.

    you may consider putting some logic gates in between with your reset control signal, so that you still have a way to control the reset pin.

    So far, we don't have the recommended voltage supervisor for this application. However, you could open a ticket in the Power management department/sector and/or under [LP] LP-VRS or [LP]LP-SP or [LP]LP-LDO; they have experts to help/support your.

    Thanks

  • 0 in reply to ChienChun Yang
    TI__Mastermind 19815 points

    Hi,
    Since I did not hear back from you, I believe my suggestions answered your questions.
    I will close this post and if you have any pending questions, feel free to post them here or open a new thread.
    Thanks and have a great day!