LMR36015-Q1: Output Capacitance Selection and

Jared Becker

Part Number: LMR36015-Q1

Hello Team,

I would like to understand what Delta Vout means in the following equation:

The datasheet says, "output voltage transient". Does that mean if I want the output voltage to deviate by less than 50mV during a load transient, I should use 50mV for Delta Vout? Any guidance you can provide would be greatly appreciated.

Thanks,

Jared

over 4 years ago

0 Daniel Li14 over 4 years ago

TI__Mastermind 27030 points

HI:

it assume the load current has a step but the inductor will limit the current raise, which take time(T) to arrive the Io, in the T time, the total energy is provide by the output capacitor which make the voltage drop.

below formullar is different from Datasheet, but it is more clear for Cout estimation.

0 Jared Becker over 4 years ago in reply to Daniel Li14

TI__Genius 11665 points

Hello Daniel,

Is there a reasonable approximation I can use for Delta Vout? Like 150mV?

Thanks,

Jared

0 Daniel Li14 over 4 years ago in reply to Jared Becker

TI__Mastermind 27030 points

Hi:

You can set 150mV during a load transient. normally you can also set at +-3%-+-5% of Voset for 25%-75% load transient with 0.1A/us current slew rate.

by the way, the output capacitor is an estimation for load transient requirement, the actual result will be variable by current slew rate, loop crossover frequency.

Thanks

Daniel Li

Power management

Power management forum

LMR36015-Q1: Output Capacitance Selection and