LM3549: Delay at Stanby and LED Current waveform

T Kishi

Part Number: LM3549

My customer has question.

1.How long does it take from turning on the power to the LM3549 until it enters the STANDBY state?

2.What is the current waveform of the LM3549?
　PWM waveform? DC current waveform?
　if you let me know what is different with the dimming method.

Best Regard

T Kishi

over 5 years ago

0 Caryss Li over 5 years ago

TI__Expert 4550 points

Hi Kishi-san,
I am looking at this, and will reply to you later. thanks.

0 Caryss Li over 5 years ago

TI__Expert 4550 points

Hi Kishi-san,
For your questions,
1. we don't have this data , but from the test on bench on EVM, it could be several ms
2. In LM3549, only one LED is on at the same time, and only the current is adjustable. that means R/G/B is turned on in turns, and dimming is done by adjusting each current when it is on.

0 T Kishi over 5 years ago in reply to Caryss Li

Genius 4425 points

Hi Caryss

Thank you for reply & confirmation.

I understood that the current waveform will be DC waveform.
Is it possible if using each EN terminal for PWM waveform?

Best Regard
T Kishi

0 Caryss Li over 5 years ago in reply to T Kishi

TI__Expert 4550 points

Hi Kishi-san,
Even you put PWM signal on EN pin, it will translated to current level, so only current amplitude is applied.

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LM3549: Delay at Stanby and LED Current waveform