TPS565201: Cout = 150uF

Stephen Turner

Part Number: TPS565201
Other Parts Discussed in Thread: TINA-TI

Hi,

I'm using the TPS565201 and need to have a total of 150uF of Cout (15 x 10uF MLCC). My output voltage is 5V and I'm using L=10uH. The datasheet says max Cout is 68uF. I have seen other issues on the E2E regarding this part saying to reduce the value of L to keep the "loop stable". Question is how to calculate the value of L for a given Cout?.

thanks

over 4 years ago

0 Andrew Xiong over 4 years ago

TI__Expert 5470 points

Hi Stephen,

For the D-CAP control converter, the inductor and capacitor will affect the loop through the double poles frequency as mentioned in equation (3) of datasheet. One easy method to determine L for loop stability is to keep the L*C value in same range of the recommended component value in Table2. But that's just for loop stability and cannot ensure the transient performance or ripple performance.

Thanks,

Andrew

0 Stephen Turner over 4 years ago in reply to Andrew Xiong

Genius 3476 points

Hi Andrew,

OK, so using Table 2 as a guide L=4.7uH and C=68uF is a working combo. If we change C to 150uF, then L becomes ~2.2uH. How would one simulate this?. Could you use TINA-TI?

thanks

0 Lishuang Zhao over 4 years ago in reply to Stephen Turner

TI__Expert 7500 points

Hi Stephen,

You can use Webench to simulate the load transient performance which is the fastest method.

Thanks,

Lishuang

+1 Stephen Turner over 4 years ago in reply to Lishuang Zhao

Genius 3476 points

Hi Lishuang,

I'm not too concerned about transient performance. I want to know if "loop stability" is met. How would I determine that with L=2.2uH and L=150uF?

thanks

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TPS565201: Cout = 150uF