TPS54541: What's the maximum duty (minimum off time ) of TPS54541

Shaquille Chen

Intellectual 1770 points

Part Number: TPS54541

Dear Team,

As title, what's the maximum duty (minimum off time ) of TPS54541?

I cannot find minimum off time request of this device.

Thanks

Shaq.

over 5 years ago

0 Katelyn Wiggenhorn over 5 years ago

TI__Genius 11040 points

Hi Shaquille,

I will discuss with the product expert tomorrow and let you know their feedback.

Best Regards,
Katelyn

0 Shaquille Chen over 5 years ago in reply to Katelyn Wiggenhorn

TI__Intellectual 1770 points

Hi Kate,

Any update?

Thanks
Shaq

0 user4134045 over 5 years ago

Intellectual 300 points

Is there any infroamtionnb updated now?

0 Katelyn Wiggenhorn over 5 years ago in reply to user4134045

TI__Genius 11040 points

Hi Shaquille,

The datasheet states:

"When operating with a low voltage difference from input to output, the high-side MOSFET of the TPS54541
device operates at 100% duty cycle as long as the BOOT to SW pin voltage is greater than 2.1 V. When the
voltage from BOOT to SW drops below 2.1 V, the high-side MOSFET turns off and an integrated low-side
MOSFET pulls SW low to recharge the BOOT capacitor. To reduce the losses of the small low-side MOSFET at
high output voltages, the low-side MOSFET is disabled at 24-V output and re-enabled when the output reaches
21.5 V."

The TPS54541 can have an effective duty cycle of 100%. (100% on) The dropout voltage will be controlled by the resistance of the power FET, diode, and DCR of the inductor.

Please let me know if anything is still unclear.

Best Regards,
Katelyn

0 Katelyn Wiggenhorn over 5 years ago in reply to Katelyn Wiggenhorn

TI__Genius 11040 points

Hi Shaquille,

Do you have any additional questions?

Best Regards,
Katelyn

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TPS54541: What's the maximum duty (minimum off time ) of TPS54541