TPS92641: Max duty cycle

Pjs

Part Number: TPS92641
Other Parts Discussed in Thread: TPS54200, TPS92200

Hi,

I'm using the duty cycle approximation equation on page 11 of the datasheet (Vout/(Efficiency*Vin)).

However, I'm finding with my chosen values that the duty cycle is larger than 1. My parameters are Vout=10.5V, efficiency=0.9, Vin=11.5V. Does this mean the TPS92641 is not a suitable choice for this small step down?

If so, can you recommend an alternate part? I'm looking for something with analogue and potentially shunt dimming options. I have a single LED chain that requires 250mA.

Many thanks

over 3 years ago

0 Frank Qiu over 3 years ago

TI__Genius 15776 points

Robin, please help in this case.

0 Yuting Shao over 3 years ago

TI__Genius 13001 points

Hi Pjs,

I find that you have post a relevant question considering of TPS54200 and I have recommended TPS92200.

But for above two devices, they supports low frequency shunt FET dimming. So what's the shunt frequency do you plan to apply?

In fact, we're developing new device which supports fast shunt dimming and it can cover all you mentioned requirements. If you can give more detailed requirements and introduce your application in detail, it's well appreciated!

Robin

0 Pjs over 3 years ago in reply to Yuting Shao

Intellectual 880 points

Hi Robin,

The new device sounds interesting - should we discuss offline so I can provide more specific details?

Many thanks

0 Yuting Shao over 3 years ago in reply to Pjs

TI__Genius 13001 points

Hi Pjs,

Of course. I'll send you the friendship request through this forum.

Robin

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TPS92641: Max duty cycle