TPS92561: Output drive

Johnson John

Part Number: TPS92561
Other Parts Discussed in Thread: TPS61196

Hello,
Per our application requirement, need to drive UV-C LEDs, 9 nos in series configuration. Typical forward drop of the LED is 8V and require 400mA forward current. (output current programmable 300mA to 500mA range) Looking for a low cost, simple, constant current LED drivers and I have come across TPS92561 device. Can you please confirm whether the selected device is suitable or any other better device is available.
Thank you

over 4 years ago

0 Johnson John over 4 years ago

Intellectual 630 points

Input voltage is 12VDC.

0 Sean Zhou over 4 years ago in reply to Johnson John

TI__Mastermind 22745 points

Hi Johnson,

I would recommend using TPS61196 which is a BOOST LED driver which can support high output voltage with external MOSFET and each channel can support up to 200mA, you can combine 6 channels together to deliver 300mA to 500mA. I don't recommend using the TPS92561 which is an old device.

Sean

0 Johnson John over 4 years ago in reply to Sean Zhou

Intellectual 630 points

Hi Sean,

Thank you for the response.

I looked into the recommended part TPS61196 and only concern is inductor size which requires 68uH due to switching frequency.

Can you recommend any other part which require small size inductor?

Thank you

Johnson John

0 Sean Zhou over 4 years ago in reply to Johnson John

TI__Mastermind 22745 points

Hi John,

We also have the LP8864S which is another boost LED driver that can support higher switching frequency with a small size inductor.

Sean

0 Johnson John over 4 years ago in reply to Sean Zhou

Intellectual 630 points

Hi Sean,

I checked this device LP8864S, the issue is the max output voltage is less than 48V. But I need above 72V (8Vf x 9nos LED) output voltage. Can you please check. The 48V is mentioned in the TI product page.

thank you

Johnson John

0 Sean Zhou over 4 years ago in reply to Johnson John

TI__Mastermind 22745 points

Hi Johnson,

For the LP8864S device, this is a boost controller and it can support higher output voltage and from the side of protecting the current sinks, for higher output voltage application, you can add a 1Mohm resistor to each current sinks as shown in TPS61196 datasheet.

Sean

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TPS92561: Output drive