TPS7B68-Q1: output cap

Mingkang Song

Part Number: TPS7B68-Q1

Hi,

Considering the output current of 150~200mA, could you pls give a recommended value for the output capacitor? (It would be better if you could tell how to calculate the value).
What is the output capacitance value in the datasheet Figure 27?

Thanks!

5 months ago

0 Juliette 5 months ago

TI__Mastermind 18466 points

Hello,

what requirements are you looking to meet in your system?

Best,

Juliette

0 Mingkang Song 5 months ago in reply to Juliette

TI__Intellectual 800 points

We now use this LDO instead of SBC to power CAN, MCU and other chips. The total current is calculated to be in the range of 150~200mA.
Although the power supply is constant, short-term interruption of 100us should be considered for testing. I understand that the capacitor cannot be too small. I wonder if you have some calculation formulas that can give a recommended value for the capacitor? Thanks!

0 Juliette 5 months ago in reply to Mingkang Song

TI__Mastermind 18466 points

We have some start-up inrush calculations that we can use: I = C(dV/dT).

Please refer to this app note for more detailed information: https://www.ti.com/lit/an/sbva060/sbva060.pdf

We also look at the capacitor impedance curves to check what effect it will have on noise and PSRR

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TPS7B68-Q1: output cap