LED Driver sugguestion

Yan Pui Chan

Intellectual 510 points

Other Parts Discussed in Thread: TPS92200, TPS92200D2EVM

Hi,

Recently, we are looking for a LED driver can meet the below requirements:-

Low cost, small package
Channel (#) – 1
Vin – 16.5V
Vout – 6V or 12V
Iout – 150mA max
Dimming method - PWM
Iq – not critical
Not required for automotive-grade

Can you recommend few parts for us to review?

Thanks,

Alan

over 4 years ago

0 Sean Zhou over 4 years ago

TI__Mastermind 22745 points

Hi Yan,

TPS92200 should be the best choice for you. It can meet all the spec requirements.

Sean

0 Yan Pui Chan over 4 years ago in reply to Sean Zhou

Intellectual 510 points

Hi Sean,

Thanks for your suggestion!

Can you please review my schematic and provide comment?

*VIN - 16.5V

0 Sean Zhou over 4 years ago in reply to Yan Pui Chan

TI__Mastermind 22745 points

Hi Yan,

The schematic looks good. Please go on the layout and refer to our layout guideline in the datasheet, the C12 and C13 should be placed near the VIN(Pin4) as soon as possible.

Sean

0 Yan Pui Chan over 4 years ago in reply to Sean Zhou

Intellectual 510 points

0 Yan Pui Chan over 4 years ago in reply to Yan Pui Chan

Intellectual 510 points

Hi Sean,

Can you let me know what is the usage for RFB? *The resistor in the blue circle.

Thanks,

Alan

0 Sean Zhou over 4 years ago in reply to Yan Pui Chan

TI__Mastermind 22745 points

Hi Alan,

This resistor is used to protect the "FB" pin when there is a short fault to the FB pin.

Sean

0 Yan Pui Chan over 4 years ago in reply to Sean Zhou

Intellectual 510 points

0 Yan Pui Chan over 4 years ago in reply to Yan Pui Chan

Intellectual 510 points

Hi Sean,

Can you let me know what is the recommended PWM frequency for the DIM pin?

We tested with different frequencies - 250Hz, 1kHz, 1.5kHz, 2kHz and 20kHz, only 20kHz has no "high pitch sound" while LED are turning.

I just want to make sure 20kHz is okay to be used.

Thanks,

Alan

0 Sean Zhou over 4 years ago in reply to Yan Pui Chan

TI__Mastermind 22745 points

Hi Alan,

Are you using TPS92200D1 or TPS92200D2? I would recommend using TPS92200D2 if you accept the analog dimming mode. Since TPS92200D2 is designed with high-frequency analog dimming mode. It can accept a 20kHz PWM dimming signal. or you can use the D1verison with analog dimming mode.

Sean

0 Yan Pui Chan over 4 years ago in reply to Sean Zhou

Intellectual 510 points

Hi Sean,

Currently, we are using TPS92200D1 for the test. I just placed an order for TPS92200D2EVM to do more tests and it should arrive tomorrow.

BTW, the analog dimming mode also uses PWM signal from our MCU side, right?

Thanks,

Alan

0 Sean Zhou over 4 years ago in reply to Yan Pui Chan

TI__Mastermind 22745 points

Hi Alan,

Yes, For TPS92200D2, it supports a 20kHz to 200kHz PWM dimming signal and the PWM signal should also come from the MCU.

Sean

0 Yan Pui Chan over 4 years ago in reply to Sean Zhou

Intellectual 510 points

Hi Sean,

Test the TPS92200D2, it is good and no more "High pitch sound".

Thanks,

Alan

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