TPS51116: PWM ON/OFF time now stable.

TAN SB

Part Number: TPS51116

Hi,

Have a question regarding the designing of TPS51116 for 1.35V DDR3L application,

I copied the circuit from the datasheet and reconfigure the output for 1.35V/0.675V DDR3L application, noticed that the PWM ON/OFF time is not consistent. What can I tweak to stabilize it.

Thanks,

over 4 years ago

0 Qian Chen over 4 years ago

TI__Mastermind 24075 points

Hi SB,

TPS51116 is DCAP mode (constant on mode) controller.

The PWM off time may vary.

Can you double check if PWM ON time is consistent?

It will be good if you can provide PWM waveform.

Thanks

Qian

0 TAN SB over 4 years ago in reply to Qian Chen

Intellectual 400 points

Hi Qian,

You are correct the OFF time varies, is this the D-CAP functioning as it is suppose to?

I was expecting the ON/OFF time to be consistent like my other DC-DC circuits which uses separate controllers and power FETs.

Thanks,

0 Qian Chen over 4 years ago in reply to TAN SB

TI__Mastermind 24075 points

Hi SB,

Looks like the part is in discontinuous mode because at no load or light load condition.

It should be fine that off time varies.

Thanks

Qian

0 TAN SB over 4 years ago in reply to Qian Chen

Intellectual 400 points

Thanks Qian.

Power management

Power management forum

TPS51116: PWM ON/OFF time now stable.