BQ51025: BQ51025

Mario Marcoccia

Part Number: BQ51025

Hi,

I need to confirm if the root for failing of many BQ51025YFPR (burnt), could be because the Input AC voltage on AC1 - AC2 input pines are more than 20Volts Pk to Pk, according the attached Oscilloscope picture. That is the wave received from a coil on(pines AC1 & AC2).

The fail in the device are not instantaneous and occur after some elapsed time (more than one months, average).

According the datasheet, the maximum voltage rate between AC1-AC2 is 20 Volts; I suppose that is Pk to Pk but I'm not sure.

Thanks.

over 2 years ago

0 Bill Johns over 2 years ago

TI__Guru 74736 points

Hello

It is possible exceeding he 20V Pk to Pk on AC1 and AC2 are causing the fail.

AC1 and AC2 are inputs to a full wave bridge, output are RECT and GND, the bridge is a synchronous bridge formed by mosfets.

Check if the bridge is damaged, shorts.

With the BQ51025 and other wireless power devices they can possible be damaged due to movement during charge. One scenario is moving RX from a large coil to coil distance to a small coil to coil distance quickly while charging. Voltage on the bridge will increase quickly, system will reduce voltage but there is a time delay in system.

0 Mario Marcoccia over 2 years ago in reply to Bill Johns

Prodigy 10 points

Thanks Bill; I'll check that.

0 Bill Johns over 2 years ago in reply to Mario Marcoccia

TI__Guru 74736 points

The BOOT1 and BOOT2 pins are voltage source of the high side mosfet for full bridge. Check them also, damage may show there.

+1 Mario Marcoccia over 2 years ago in reply to Bill Johns

Prodigy 10 points

I'll do. Thanks!

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BQ51025: BQ51025