TPS61093: Small Signal Stability

Shuji Ishiwata

Mastermind 7855 points

Part Number: TPS61093

Tool/software:

Hi All,

I have some questions about the TPS61093.

(1) What resistance does Ro in Equation 7 on page 14 represent?

(2) Is 10nF the recommended value for the Cff capacitor?

(3) What values should Fp, Fp-f, and fz-f be set to?

Best Regards,
Ishiwata

5 months ago

+1 Brigitte 5 months ago

TI__Guru 66350 points

Hello Shuji,

1. Ro is the output or load resistance.

2. Figure 9 shows you at which frequency you should set the pole and zero and then you can calculate the needed feed-forward capacitor out of equations 8 and 9.

3. Fp is coming from your load resistance and the output capacitor you are using, Fpf and Fzf shall be set like in Figure 9.

Best regards,
Brigitte

0 Shuji Ishiwata 4 months ago in reply to Brigitte

Mastermind 7855 points

Hello Brigitte,

Thank you for your answer.
I understand.

We need to set Fpf to be fp-ea in Figure 9, and set Fzf to be fzea.
Also, you can calculate Cff from each of those frequencies.

Best Regards,
Ishiwata

0 Shipeng Cheng 4 months ago in reply to Shuji Ishiwata

TI__Genius 17610 points

Hi Ishiwata,

Do you have questions about compensation?

0 Shuji Ishiwata 4 months ago in reply to Shipeng Cheng

Mastermind 7855 points

Hello Brigitte,

Sorry for the late reply.
Thank you for your reply.
I have no further questions.

Best Regards,
Ishiwata

0 Shipeng Cheng 4 months ago in reply to Shuji Ishiwata

TI__Genius 17610 points

Thank you. I will close this.

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TPS61093: Small Signal Stability