TPS92390: Does the Vout changes automatically according to the number of the LED connected?

David Huang

Intellectual 2285 points

Part Number: TPS92390

Does the Vout changes automatically according to the number of the LED connected in series?

For example,

If I connect 10 LEDs with 1.5V forward voltage each, does that make the Vout 20V?

If I connect 20 LEDs does the Vout change to 40V?

Thanks

over 4 years ago

0 Yuting Shao over 4 years ago

TI__Genius 13001 points

Hi David,

This device has adaptive boost output function, and device will convert the most lowest voltage to light the LED.

BR,

Robin

0 David Huang over 4 years ago in reply to Yuting Shao

TI__Intellectual 2285 points

Hi Robin

Could you provide more details about how this works?

If 10 or 20 LEDs with each 1.5V forward voltage are being connected what are we expect to see for the Vout?

Thanks

0 Frank Qiu over 4 years ago in reply to David Huang

TI__Genius 15776 points

Robin, please keep following this case,

0 Yuting Shao over 4 years ago in reply to David Huang

TI__Genius 13001 points

Hi David,

The quantity of LED for each channel should be same then his function can work normally. For detailed operation principle, pls refer the section 7.3.6.3 in the datasheet.

BR,

Robin

0 David Huang over 4 years ago in reply to Yuting Shao

TI__Intellectual 2285 points

Hi Robin

Thanks for answering.

You mentioned that the quantity of LED for each channel should be the same, could you check whether the applications below is possible for the customer?

And if they don't, what's the reason causing the problem and how to solve it.

1. 5 LEDs connected to out1 and out2, out3 and 4 open

2. 10 LEDs connected to out1, 2 and 3, out4 open

3. 12 LEDs connected to out1 and 2, 14 LEDs connected to out3 and 4 (and which channel would the adaptive boost output function be applied in this case?)

Regards

David

+1 Yuting Shao over 4 years ago in reply to David Huang

TI__Genius 13001 points

Hi David,

The fist two connection is OK. The last operation will cause LED_SHORT fault because boost will output voltage based on the highest channel's requirement. For detailed info, pls refer section 7.3.9.3.2 of the datasheet.

BR,

Robin

Power management

Power management forum

TPS92390: Does the Vout changes automatically according to the number of the LED connected?