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TPS54719: TPS54719RTER

Part Number: TPS54719
Other Parts Discussed in Thread: TPS62811-Q1, TPS628501

Hi,

We are using the TPS54719RTER buck converter for 1.8V and 1V for our application having two FPGAs (XC7S50-1FGGA484C, Spartan-7 series ).

Following is the requirement,

For 1V

Vin -   5V

Vout - 1V

Iout - 200mA  (Static load)

total load capacitance -  120uF  (decoupling capacitors) 

For 1.8V

Vin -   5V

Vout - 1.8V

Iout - 200mA  (Static load)

total load capacitance -  540uF  (decoupling capacitors) 

We need to know the how much inrush current will drive through the Input supply and whether it is reliable solution, possibly share waveform for the same.

We simulated the above requirement in Webench but could not able to find to simulate with adding capacitive load and with dynamic load.

For reference, attach the circuit.

Thanks.

  • Hi,

    The TPS54719 is a very old device.  Why do you want to use it?

    With your very low load currents, you can use the TPS628501.  Or, the larger TPS62811-Q1 supports a larger capacitive load.

    The inrush current for any buck can be estimated by Iout = Cout * Vout / Tss + Iload.  The inrush into the output is the load current during soft start + the current required to charge the output caps.  Then, convert this output current to an input current with: Iin = Iout * Vout / (Vin * eff.)

    Thanks,

    Chris

  • Thank you. Will consider the suggested part.