TPS61177A: Met some question in dimming

Zhanpeng Li

Intellectual 2140 points

Part Number: TPS61177A

Hi team,

we are using the TPS61177A in tablet and met some question in dimming.

DIMMING MODEL: Mix

Frequency:600khz

schemtic:

input: single cell

Load:9x6 LED

Output voltage:27V@21x6mA

question:

when change the D of PWMB from 0 to 50%, the Light intensity could be change from the incearse of D; However when change the D from 50% to 100%, the light could not be change through PWMB.

could you help give me some insights about this question?

Brandon

over 4 years ago

0 Yuting Shao over 4 years ago

TI__Genius 13001 points

Hi Brandon,

How do measure the light intensity? Since human eyes are not sensitive to intensity change in high brightness, you'd better measure the output current when adjusting PWM duty cycle.

0 Yuting Shao over 4 years ago

TI__Genius 13001 points

Hi Brandon,

Since it has been long time, I will close this thread. If you have further questions, pls. ask a new question. Many thanks!

BR,

Robin

Because of the Thanksgiving holiday in the U.S., TI E2E™ design support forum responses may be delayed from November 25 through December 2. Thank you for your patience.

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TPS61177A: Met some question in dimming