Tps92640/41 t on time and sw frequency

ruben.jonsson

Prodigy 200 points

Hi,

How does t on time and/or switch frequency change when changing led current with analog dimming.

Thanks

over 8 years ago

0 ruben.jonsson over 8 years ago

Prodigy 200 points

Answering my own question if anyone else wants to know:

On time remains constant and off time is momentarily increased or decreased (frequency decreased or increased) until current has stabilized on new set value. Frequency is then roughly back to same as before change.

0 Clinton Jensen over 8 years ago in reply to ruben.jonsson

TI__Mastermind 25500 points

Yes, the on time is based on both the input and output voltages. It will reduce as the input increases, or reduce as the output decreases (which it will some when analog dimming) to give you a constant switching frequency.

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Tps92640/41 t on time and sw frequency