TPS922054: Powering 12V LED Strip With 12V input to Driver

Kaleb Morgan

Part Number: TPS922054

Tool/software:

Hello,

We are trying to pull 1A through a 12V LED strip. The voltage drop across these LEDs is 11.6V @ 1A.

1. Is it possible to use a 12V supply to power these LEDs while making use of the TPS922054?
2. Looking through the datasheet and forums we have come across a VCC_TH variable (section 8.3.6 of the datasheet). Does VCC_TH = (Vin_min - Vout_max) * R_UVP2 / (R_UVP1 + R_UVP2) > 1.4V? If not what is it?
3. It is also mentioned here https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1288219/faq-how-to-design-the-uvp-resistor-divider-for-tps922055-tps922054-tps922053-tps922052 in Steven Li's answer (number 4) that UVP can be left floating if not used. Does this mean we dont have to worry about the 1.4V? We worry that we will need Vin_min = Vout_max +1.4V.

8 months ago

0 Steven Li 8 months ago

TI__Mastermind 23150 points

Hi Kaleb,

Please refer to my comments below:

Kaleb Morgan said:
1. Is it possible to use a 12V supply to power these LEDs while making use of the TPS922054?

Please double check if your LED strip should be powered by a constant-voltage source or constant-current source.

Kaleb Morgan said:
2. Looking through the datasheet and forums we have come across a VCC_TH variable (section 8.3.6 of the datasheet). Does VCC_TH = (Vin_min - Vout_max) * R_UVP2 / (R_UVP1 + R_UVP2) > 1.4V? If not what is it?

If you only need to drive LED, then you do need to care about the V_CC_TH. Normally only those who use this device for battery charging should care about this parameter.

Kaleb Morgan said:
3. It is also mentioned here https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1288219/faq-how-to-design-the-uvp-resistor-divider-for-tps922055-tps922054-tps922053-tps922052 in Steven Li's answer (number 4) that UVP can be left floating if not used. Does this mean we dont have to worry about the 1.4V? We worry that we will need Vin_min = Vout_max +1.4V.

If you are going to use TPS922054 to drive a 11.6V LED string with a 12V input voltage (if this LED strip should indeed be driven by a constant current source), then you should leave the UVP pin floating. Please refer to this FAQ - [FAQ] How to design the UVP resistor divider for TPS922055 / TPS922054 / TPS922053 / TPS922052? - Power management forum - Power management - TI E2E support forums.

Best Regards,

Steven