TPS54201: Vi versus Vo requirement?

Jamie Wiemeyer

Part Number: TPS54201

I seek to understand what behavior will result when the Vi input voltage approaches the LED voltage at the Vo output. In other words... assume a 6Vf LED in a battery powered device; what happens when the battery discharges and Vi approaches the 6V LED level? Will the supply remain stable? I seek to know the Vi voltage where the regulator operates acceptably.

Jamie

Primex

708.738.7851

over 5 years ago

0 Sean Zhou over 5 years ago

TI__Mastermind 22745 points

Hi Jamie,

When the supply voltage reaches to the output LED forward voltage, it will decrease the output current and when the supply voltage is below LED forward voltage, it will turns off.

Sean

0 Jamie Wiemeyer over 5 years ago in reply to Sean Zhou

Prodigy 20 points

Sean,

Thank you for your prompt reply. I understand that the regulator will turn off when the input goes below the LED's Vf.

Just to verify, the TPS54201 buck regulator has no stability problem with the high duty cycles (duty cycle of the 600kHz switching waveform) as Vi approaches Vo?

Jamie

0 Sean Zhou over 5 years ago in reply to Jamie Wiemeyer

TI__Mastermind 22745 points

Hi Jamie,

Yes, there is no issue with the loop.

Sean

Power management

Power management forum

TPS54201: Vi versus Vo requirement?