TPS92074: Is Analog Dimming possible from 0% - 100%

Frits Wateren

Part Number: TPS92074

Dear TI,

Referring to the data sheet of the TPS92074 (SLUSBO7-Aug 2013) I have a question regarding the schematic in Figure 19. I would like to dim the light of the LED-string from 0% gradually up to 100%. But looking at the schematic I doubt if this is possible considering the diode and transistor in the input circuit. Also there is no description of operation referring to this figure. Could you give me some more insight in this?

Thanks

Frits

over 6 years ago

0 Irwin Nederbragt over 6 years ago

TI__Mastermind 28655 points

Hello Frits,

There is a diagram of Analog dimming in the datasheet:

If you use the 0-3V Analog DIM Signal you can adjust the output current.

The diode and transistor in the input circuit is to create the VCC for the IC so it depends on how your are dimming the converter. If you are trying to do this from dimming the input source voltage it probably won't work.

Best Regards,

0 Frits Wateren over 6 years ago in reply to Irwin Nederbragt

Prodigy 40 points

Hi Erwin,

Thanks for your info. I will order an evaluation board and do some more detailed experiments on this.

Cheers,

Frits

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TPS92074: Is Analog Dimming possible from 0% - 100%