TPS54160A: TPS54160A

Juzer Tarwala

Part Number: TPS54160A

Hi, Team

I calculated values on based the equation (48)~(50) for the typical application of the datasheet.
Vout=3.3V, Gmod(fc)=0.542, gm(EA)=97uA/V, VREF=0.8, fp(mod)=1.5kHz, Cout=47uF, RESR=10mΩ
The result is following;
- Rc=3.3/(0.542*97u*0.8)=78.46kΩ (76.2kΩ)

- Cc=1/(2π*78.46kΩ*1.5kHz)=1352pF (2710pF)

- Cf=47uF*10mΩ/78.46kΩ=5.99pF (6.17pF)

The values inside the parentheses are the result of the datasheet.

Cc=1352pF or 2710pF
Which is correct?

When I replace '2π' with 'π' in the Cc equation i got the result same as mentioned in the datasheet. So i am little bit confused which formula to use for calculating Cc.

Etheir Cc=1/(2π*78.46kΩ*1.5kHz) = 1352pF OR Cc=1/(π*78.46kΩ*1.5kHz) =2705pF

Thanks and Regards,
Juzer Tarwala

over 4 years ago

0 Daniel Li14 over 4 years ago

TI__Mastermind 27030 points

the formula is right, and for zero position, put before pole is also OK for make the loop stable. The formula is for choosing right value component. after you put the component into the board, you still need test bode plot and adjust the value for get a better loop performance.

Thanks

0 Juzer Tarwala over 4 years ago in reply to Daniel Li14

Prodigy 120 points

Hi Daniel,

Thank for your reply.

So you mean to say that Cc=1/(2π*78.46kΩ*1.5kHz) = 1352pF is the correct equation and the value of Cc=2710pF calculated as per the datasheet is for making the system stable?

0 Daniel Li14 over 4 years ago in reply to Juzer Tarwala

TI__Mastermind 27030 points

yes, that's right. I will more prefer you can test the loop for validating you loop compensation result.

Thanks

0 Juzer Tarwala over 4 years ago in reply to Daniel Li14

Prodigy 120 points

ok thank you for the help Daniel.

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TPS54160A: TPS54160A