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PTH04070W: About Inhibit(5pin)

Guru 15995 points

Replies: 5

Views: 63

Part Number: PTH04070W

Hi Team,

 

We would like to control Inhibit(5pin) by Logic signal(High and Low) without Nch MOSFET.

-OUTPUT is Enable at Inhibit pin is High

-OUTPUT is Disable at Inhibit pin is Low

 

Therefore, I have four questions.

 

*By the way, we understand that “This control pin has an internal pullup to the input voltage VI”

and “An open-collector or open-drain device is recommended to control this input.”

 

--------

[Q1]

Can PTH04070WAH receive the voltage more than Input voltage(VI)?

For example, VIN=3.3V, Inhibit =5V

 

[Q2]

Can PTH04070WAH receive the voltage same as Input voltage(VI)?

For example, VIN=3.3V, Inhibit =3.3V

 

[Q3]

Could you please let us know ABSOLUTE MAXIMUM RATINGS of Inhibit(5pin) voltage?

 

[Q4]

Could you please let us know if you have any concern for the following circuit?


--------

 

Regards,

Kanemaru

  • Hi Kanemaru,

    There is a footnote (#3) on page 3 that prohibits tying the inhibit pin to Vin (your 3.3V).  It should not be tied to a voltage higher than Vin either.  Please drive the inhibit pin with an open drain control circuit.

    Chris Glaser

    Texas Instruments

    ________________________________

    TPS62147 – New 17Vin, 2A buck with forced-PWM option for low output ripple.
    1% accuracy over temperature, 0.8V to 12Vout, pin-compatible to 4A (TPS62136), for industrial applications.

  • Guru 15995 points

    In reply to Chris Glaser:

    Hi Chris-san,

    Thank you for your prompt reply.

    I understand. Thank you very much.

     

    Regards,

    Kanemaru

  • Guru 15995 points

    In reply to Hide:

    Hi Chris-san,

     

    I have one more question.

     

    We would like to connect the inhibit pin to another module's inhibit pin.

    Because, we would like to control the inhibit pins by one switch.

    (Please refer to the following figure.)

     

    According to datasheet, “Do not tie the inhibit pin to another module's inhibit pin.”.

    Therefore, I understand that I can’t use this circuit.

    Is my understanding correct?

     

    If yes, could you please let us know the reason?

    (For example, if I connect the inhibit pin to another module’s inhibit pin, device is broken / malfunctions etc. )

      

     

    Regards,

    Hide

  • In reply to Hide:

    Hi Kanemaru-san,

    You are correct.  You cannot use this circuit.  You must use a switch for each module.  The internal circuit which turns on each module is driven from each module's own internal voltages.  These voltages must be kept separate.

    There may be a newer, better device for your application.  What Vin, Vout, and Iout do you need in your application?

    Chris Glaser

    Texas Instruments

    ________________________________

    TPS62147 – New 17Vin, 2A buck with forced-PWM option for low output ripple.
    1% accuracy over temperature, 0.8V to 12Vout, pin-compatible to 4A (TPS62136), for industrial applications.

  • Guru 15995 points

    In reply to Chris Glaser:

    Hi Chris-san,

    Thank you for always kind support.

    I would like to use this device because it is very easy to use.

    So, I will think about it

    Regards,

    Hide