LP8868X-Q1: LED Driver PWM Issues

Balaji Padmanaban

Part Number: LP8868X-Q1

Tool/software:

HI,

Attached is my design.

Issue is when i increase PWM the inductor ripple increases, and the input voltage drops below 4.6V.

Using in PWM Mode

Am suspecting

1. RCOMP,COMP,RDAMP Values

2.RTH

3.INput capacitance

Inductor calculations are fine i my belief

can TI share an calculation tool

0 Gracie Guo over 1 year ago

Our expert is out of office and will reply to you later.

BR, Gracie

0 Balaji Padmanaban over 1 year ago in reply to Gracie Guo

Sure, and the convertor ripple increases and inductor heats leading to more ripple. right now i have 200uH.SRR4828A-221M

0 Zhiqian Wu over 1 year ago in reply to Balaji Padmanaban

Hi, Balaji

May I ask what is the output current/VIN and VOUT?

Depending on your schematic, 500mA inductor may not enough for the design.

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