BQ25710: not work in the correct mode

user4207162

Part Number: BQ25710

input voltage：20V

output voltage:13.2V

I think BQ25710 should operates in buck mode, but it works in buck-boost mode.

At the beginning, the input voltage is 5V, but when it up to 20V, the charger should change operation mode from buck-boost mode to buck mode.

Is there any way to adjust the operation mode?

over 4 years ago

0 Kedar Manishankar over 4 years ago

TI__Mastermind 24075 points

Hi,

BQ25710 has seamless transition between the modes. With input voltage 20V, and output voltage 13.2V, you should observe SW1 switching, as well as HIDRV1 ad LODRV1, while HIDRV2 is always on.

0 user4207162 over 4 years ago in reply to Kedar Manishankar

Prodigy 30 points

This is a notebook application. With battery, it could switch from buck-boost mode to buck mode when input voltage change from 5V to 20V.

But without battery, it still works in buck-boost mode when input voltage change from 5V to 20V. SW1 and SW2 both switching.

PS: With and Without battery, charger output voltage both set 13.2V.

0 Tiger Zhou over 4 years ago in reply to user4207162

TI__Mastermind 33525 points

What is your charge current? At no load or light load, the part may operate with both SW1 and SW2 switching.

0 user4207162 over 4 years ago in reply to Tiger Zhou

Prodigy 30 points

Without battery, charging current will be set to 0A but system current about 2A. It still works in buck-boot mode.

At light load, the part may operate with both SW1 and SW2 switching. --------------what is the light load current, less than 1A or other?

Light load, the part may operate with both SW1 and SW2 switching. I think it may affect the efficiency of charger.

0 Tiger Zhou over 4 years ago in reply to user4207162

TI__Mastermind 33525 points

We have many efficiency curves in the datasheet. Could you provide a waveform for your specific test conditions?

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BQ25710: not work in the correct mode