TPS65185: TPS65185 / Start up issue

S.Satoshi

Part Number: TPS65185

Hi,

The customer find start up issue at few samples in their production line. I'd like to provide detailed information including schematic, so can you find my contact information in profile and send email?

They mounted the failed sample on EVM and could duplicate this waveform.
They changed only one external component on EVM (R10 to 39k : VDD=27V)
VIN=VIO=3.5V, PWRUP=VIO, VCOM_CTRL=GND
They could see the same waveform at 9pcs samples per 480pcs

Best Regards,

Satoshi / Japan Disty

over 6 years ago

0 Richard Solarski over 6 years ago

TI__Genius 10885 points

Satoshi-san,

It appears their charge pump is crashing, something that can occur when VEE_D and VDDH_D do not have 100nF capacitors to GND or there is significant inductance in the layout.

Best Regards,
Rick S.

0 S.Satoshi over 6 years ago in reply to Richard Solarski

Guru 21675 points

Hi Rick,

The EVM has 100nF capacitor on VEE_D and VDDH_D actually that is C35 and C36. The latest schematic is uploaded in following thread.

e2e.ti.com/.../1997848

This means that the this start up failure can be seen with this C35 and C36 capacitor. I hope to discuss further off line.

Best Regards,
Satoshi

Power management

Power management forum

TPS65185: TPS65185 / Start up issue