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LP8863-Q1: Power supply circuit of LP8863-Q1

Masami Michino
Genius 5070 points
Part Number: LP8863-Q1
Other Parts Discussed in Thread: LP8860-Q1


Dear, All

I have a question about how to use LP8863-Q1.
I want to suggest with 2ch pair because the current is large from customer's specifications.
In this case, the number of Ch is insufficient in LP8863-Q1.
For this reason we are considering a two-device configuration.
However, for LEDs, turn on only one channel at a time.
For that reason, I would like to share a buck-boost power supply.

question 1:
Since there is a mode in which the LP8863-Q1 uses an external power supply, can this power supply be shared by another LP8863-Q1 the buck-boost power supply circuit?

This configuration is better if it can be used in pairs of LP8863-Q1 and LP8860-Q1.
Question 2:
Is it possible to use LP8863-Q1 and LP8860-Q1 pair using the buck-boost power supply of LP8863-Q1?

Thanks, Masami M.

  • 0
    TI__Expert 4565 points

    Hi Michino-san,

    I don't recommend using Vout of one LP8863-Q1 for another LP8863-Q1 for LED high voltage by these reasons.

    1. Switching current for one LP8863-Q boost may become too high causing thermal/efficiency issue

    2. If brightness setting of 2 LP8863-Q1 is different each other, adaptive boost will dynamically change boost output voltage, and this voltage may be too low or too high for LP8863-Q1 using external voltage

    3. User should use cluster mode for this connection of 2 LP8863-Q1, and will lose advanced brightness control such as dithering, slope control, and hybrid dimming

    I think individual connection of 2 LP8863-Q1 with individual(or same) PWM input depending on brightness control needs

    I will be able to recommend better if I can figure out your apps case better.

    Hope this helps,