TPS922055DRRREVM: Current Limiting Issue

Kaleb Morgan

Prodigy 10 points

Part Number: TPS922055DRRREVM

Tool/software:

I am using the TPS922055DRRREVM eval board and I am unable to limit the current. I am using an off the shelf LED strip rated for 12V, 1A. My external power supply is set to output 18V and is capable of 1.5A. I have replaced the 50mΩ resistor (R1) with a 200mΩ to limit the current to 1 amp. ADIM/HD and PWM are both tied high using the provided jumpers. When I connect everything and power the board up, my current consumption shoots to 1.5A.
I can’t seem to get the red fault LED to turn off and I have verified that I am not in violation of any criterion as shown in table 8-3 of the TPS92205x datasheet.

11 months ago

0 Jared Zhou 11 months ago

TI__Mastermind 20515 points

Hi Kaleb,

Steven is OoO, please expect some delay on the response. Thanks for your patience.

BR, Jared

+1 Steven Li 11 months ago

TI__Mastermind 23190 points

Hi Kaleb,

Sorry for the late response. Please follow the below sequences and check the behavior of the circuit.

First set EN/PWM pin to GND with the jumper
Then Power up your external power supply
Then set EN/PWM pin to high with the jumper

Please check the behavior of the circuit at this time.

Best Regards,

Steven

0 Kaleb Morgan 11 months ago in reply to Steven Li

Prodigy 10 points

Hello Jared and Steven,

Thank you for the assistance. Steven, the sequence you specified seems to have solved my problem. The fault light no longer appears and I am now limited to 1A.

Thank you!
Kaleb

0 Steven Li 11 months ago in reply to Kaleb Morgan

TI__Mastermind 23190 points

Hi Kaleb,

You are welcome.

I am going to close this thread. Please feel free to contact me again if you have any further question.

Best Regards,

Steven

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TPS922055DRRREVM: Current Limiting Issue