TPS62913: duty cycle violation?

Hans

Part Number: TPS62913

Hello Team,

in order to reduce the slew rate of the sync-clock a RC filter may be used as shown below. Will synchronization still work with the thresholds of 1.1V (on) and 0.4V (off) because duty cycle will be out of spec?

Does the SYNC-Input have internal Schmitt-Trigger?

Thank you and best regards, Hans

over 1 year ago

0 Hongjia-Wu over 1 year ago

TI__Expert 6680 points

Hi Hans,

The device will detect the voltage on EN/SYNC and take voltage>1.1V as high and voltage<0.4V as low and the duty cycle is created based on this.

And yes this feature should be realized by the internal Schmitt-Trigger.

Regards,

Emma Wu

0 Hans over 1 year ago in reply to Hongjia-Wu

TI__Genius 12865 points

Hello Emma,

can you also tell me if the red curve (after low pass filter) in above diagram will work for the SYNC pin, please?

Thank you and best regards, Hans

0 Hongjia-Wu over 1 year ago in reply to Hans

TI__Expert 6680 points

Hi Hans,

Why do you want to reduce the slew rate for the clock? Is that for the noise immunity consideration?

And yes as long as the timing requirement and voltage level both meet below specs in the EC table, the applied the signal will work for the SYNC pin.

Regards,

Emma Wu

+1 Lucia Gao over 1 year ago in reply to Hongjia-Wu

TI__Mastermind 30241 points

Hi Hans,

Add more comment from my side. We have tested the TPS62913 with duty cycles outside of the 45%-55% limits in the datasheet and have not seen any issues. An example of the device operating with an external sync with 70% duty cycle is shown below:

Thanks!

BRs

Lucia

0 Hans over 1 year ago in reply to Lucia Gao

TI__Genius 12865 points

this is what I call "first class support!" :-)

Thank you, Hans

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TPS62913: duty cycle violation?