TPS40170: TPS40170 Error Amplifier Questions

Chris Hickam

Intellectual 260 points

Part Number: TPS40170

What are the typical values for the rails and the positive and negative slew rates of the TPS40170 error amplifier?

over 6 years ago

0 Samuel Jaffe over 6 years ago

TI__Mastermind 25590 points

Chris,

Let me consult with the team. I'll try to have an answer by the end of the day today.

Thanks,
-Sam

0 Samuel Jaffe over 6 years ago in reply to Samuel Jaffe

TI__Mastermind 25590 points

Chris,

The slew rate is set by the 2mA sink/source current and the impedance of the compensation network.

-Sam

0 Chris Hickam over 6 years ago in reply to Samuel Jaffe

Intellectual 260 points

Sam,

So the slew rate is limited strictly by the current capability of the amplifier and the internal capacitance of the error amplifier is not significant enough to impact it for this design. Based on my compensator with C3=390pF it should take roughly 1.37us to reduce the error amplifier output from 8 to 1V if the positive rail is 8V. If it is 7V it will only take about 1.17us. I suppose 200ns isn't worth worrying about too much. I'll just make the amplifier rails in my model 0.7V and 7.3V,

Thanks for your help,

Chris

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TPS40170: TPS40170 Error Amplifier Questions