TPS61165: 1Hz - 100Hz PWM dimming 20 IR LED solution

Will Wang47

Part Number: TPS61165

Hi team,

Customer comes to us for a solution to drive 20 IR LED(Vf=1.5V at 20mA). VIN is 2.9V ~ 4.5V, dimming frequency 1Hz to 100Hz, LED on time = 1ms. Waveform could refer following:

The 20 LED could be one string or several string, but need use 1 part.

Based on customer requirement, could you help check if we get any solution for them?

Thanks and Best Regards,

Will

over 2 years ago

0 Patrick Yao over 2 years ago

TI__Mastermind 34780 points

Hi Will,

I think one possible way is customer can use TPS61165 EN to do on/off to IC to achieve dimming frequency below 100Hz.

May I know why they need such low dimming frequency? And maybe I can have a bench test to see if TPS61165 can support this case.

Patrick

0 Will Wang47 over 2 years ago in reply to Patrick Yao

TI__Expert 7710 points

Hi Patrick,

Customer would like to use this as a flash camera light, so they use it like this. Could you help check if this workable on this?

I see CTRL is a delay between low high and output switching, does this OK for TPS61165 CTRL work as PWM dimming control?

Thanks and Best Regards,

Will

0 Patrick Yao over 2 years ago in reply to Will Wang47

TI__Mastermind 34780 points

Hi Will,

Let me find another suitable device for you. TPS61165 is not the perfect choice since it doesn't have real EN pin.

And is the digital interface like I2C needed?

Patrick

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TPS61165: 1Hz - 100Hz PWM dimming 20 IR LED solution