TPS61060: Maximum Duty of PWM Brightness Control

Kuramochi Tadahiko

Guru 28715 points

Part Number: TPS61060

Hi,

My customer is considering to use the TPS61060 on high duty as high as possible.

Trying 99.6% duty ratio, the device operation didn't go well as linked "original question"..

How much can PWM control be set higher?

Best Regards,

Kuramochi

over 6 years ago

0 Hak-Leong Ng over 6 years ago

TI__Intellectual 1985 points

Hi Kuramochi,

Where did you apply this control signal? If you are using PWM to control the brightness, I have to assume you connect your control signal to EN pin.

There are some limitations in using PWM connected to EN pin to control the brightness

1. The PWM control signal should not be higher than 1KHz.
2. The PWM low-level signal time ( tPWML ) should be less than 25ms or else the device might enter shutdown mode. i.e. Your PWM should be higher than 40Hz if you want full control of the brightness from 0% to 100%.

You can refer to the footnote on page 5 in the datasheet for more information.

You can also control the brightness using the digital control scheme by connecting a control signal (NOT PWM) to pin ILED. You can refer to section 8.4.2 for more information.

When you mentioned "device operation didn't go well", can you elaborate ? Did you have some measurement of the current ? low brightness not working well or high brightness not working well?

Regards
H L

0 Hak-Leong Ng over 6 years ago in reply to Hak-Leong Ng

TI__Intellectual 1985 points

Hi Kuramochi,

Is your problem resolved?

If you don't have any more questions, I will consider this case closed.

Regards
H L

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TPS61060: Maximum Duty of PWM Brightness Control