TPS92511: LED current lower than 150mA

Hello Franz,

According to the datasheet:  "To ensure stability, RIADJ must be less that 30 kΩ, implying a minimum ILED of 50 mA can be programmed. The
tolerance of ILED of 150 mA is shown in the ELECTRICAL CHARACTERISTICS."

It's close, however operating out of the recommended range can lead to issues.

Do they need common anode?

Best Regards,

Hi Irwin,

Yes, is there any common anode constant current LED driver that can support 40mA current setting?

Best regards,

Franz

Hello,

The LM3445/LM3444 are controllers that could do this, they were created for a different purpose but are fairly simple parts to use.

What is your input voltage, output voltage and any other relevant information for this design?

Best Regards,

Hi Irwin,

Thank you for your response.

Input voltage would be 18V to 32V and will have 1 to 5 LEDs connected.

Best regards,

Franz

Hello Franz,

The LM3444/45 should work, just have to generate a voltage for VCC.  Also, if you go this route make sure that you meet the minimum on-time requirement since you will have low duty cycle with 1 led and 32V input.

You can look at those part's datasheets.  The circuit will be reduced from what you see since these were meant for off-line.  I've worked with these parts quite a bit if you need direction.

Best Regards,

Hi Irwin,

Good day!

Just a follow-up inquiry on this. Is LM3414HV capable to be used with 40mA LED current?

Best regards,

Franz