TPS92515HVEVM-749: Driving current waveform

Eddy Lo1

Prodigy 70 points

Part Number: TPS92515HVEVM-749
Other Parts Discussed in Thread: TPS92515, LM3405, LM3410, TPS92513, TPS92515HV

I'm looking for a device to driver single LED in range of 350~900mA with continuous wave. Input voltage 5V.

Is TPS92515 with analog dimming mode good to go?

over 5 years ago

0 Irwin Nederbragt over 5 years ago

TI__Mastermind 28655 points

Hello,

Not sure what a continuous wave means? TPs92515 is 5.5V minimum input voltage. Look at the LM3405. We do not have many parts that run at 5V input as a buck converter. Another option is the LM3410, it can be used as a SEPIC. Neither of these have analog dimming but if the analog dimming is limited it may be possible.

Best Regards,

0 Eddy Lo1 over 5 years ago in reply to Irwin Nederbragt

Prodigy 70 points

Hi Irwin,

Thanks for highlighting the input voltage of TPS92515, I had confused with TPS92513.

The continuous wave is referring to the drive current supplied directly to the LED, a DC current produces a CW light output while an AC current waveform supplied to the LED produces an time varying light output.

What is the driving current waveform of TPS92515 in CCM mode?

Warmest regards!

0 Irwin Nederbragt over 5 years ago in reply to Eddy Lo1

TI__Mastermind 28655 points

Hello,

Yes, the TPS92513 should work for this. If a DC voltage is supplied the LED will have non-time varying continuous current flow. It will be a saw-tooth waveform that can be reduced with output capacitance. Analog dimming range is 10:1.

Best Regards,

0 Eddy Lo1 over 5 years ago in reply to Irwin Nederbragt

Prodigy 70 points

Thanks Irwin,

Is TPS92515HV in CCM mode also saw-tooth waveform?

warmest regards!

Eddy

0 Irwin Nederbragt over 5 years ago in reply to Eddy Lo1

TI__Mastermind 28655 points

Hello Eddy,

Yes, the inductor current will be a saw-tooth with a DC offset. If there is an output capacitor the LED current will start looking more sinusoidal. This is true with most of the LED buck converters.

Best Regards,

Power management

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TPS92515HVEVM-749: Driving current waveform