TPS54531: Compensation Components Selection "Crossover frequency"

user4960855

Part Number: TPS54531

I can't understand "Compensation Components" by looking at the datasheet or other questions.

The conditions of use are as follows.

　Vin＝12~24.6V

　Vout＝5.2V

　Iout(max)＝0.7A

　L＝47uH(100mΩ)

When using Webench, other parameters are as follows.

　Cout＝10uF(3mΩ)

　Rcomp＝100Ω

　Ccomp＝22nF

　Ccomp2＝4.7nF

And the simulation result is Gain Marg = -11.23 dB, Phase Marg = 67.42 Deg, Cross Freq = 2.54 kHz.

I think Gain Marg and Phase Marg are fine.

However, the Cross Freq is as low as 2.54 kHz.

I understand that Cross Freq is desirable to be around 20kHz,

but do you think the simulation result of this Webench is good?

0 Zhao Ma over 4 years ago

Hi, Sir

1. First of all, why do you use a 5A device while max loading is 0.7A?

2. For your case, TI still suggests using max loading 5A to create Webench design, then bandwidth will be large.

0 user4960855 over 4 years ago in reply to Zhao Ma

Hi, Sir

Thank you for your quick response.

1. First of all, why do you use a 5A device while max loading is 0.7A?

＞I plan to use the TPS54531 to generate multiple voltages

　The above 0.7A (max) is a part of it.

　I want to use TPS54531 even at 0.7A (max) to unify the parts.

2. For your case, TI still suggests using max loading 5A to create Webench design, then bandwidth will be large.

＞Even if Iout is less than 5A, should it be calculated at 5A in Webench design?

Thanks.

Best regards.

0 Zhao Ma over 4 years ago in reply to user4960855

Hi, Sir

1. Got you.

2. Yes, I think the 5A design can cover your 0.7A application.

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