The BSTOUT pin of STPMIC1APQR already has a 5.2V voltage output, and the SWIN pin is directly connected to the BSTOUT pin, but SWOUT has no voltage output. what error will cause this problem?

[YZhan.3]

First briefly introduce our motherboard. STM32MPU151AAC3 (361-pin TFBGA package) is used in our motherboard, and STPMIC1APQR is used in the power supply. At present, booting from Micro-SD card is normal, DDR3L and e.MMC are working normally. 

Issue : 

The BSTOUT pin of STPMIC1APQR already has a 5.2V voltage output, and the SWIN pin is directly connected to the BSTOUT pin, but SWOUT has no voltage output that supply USB-HOST VBUS. By the way, our circuit schematic refered to STPMIC157A-EV1 and has been reviewed by ST engineers. Our BSP engineers have configured the STPMIC USB power supply in the same way as the 157A-EV1.

Ask: 

SWOUT has no voltage output, what error will cause this problem?

[Olivier GALLIEN]

Hi @YZhan.3​ 

Quite an old post, sorry for late reply.

Supposed you find issue by yourself ?

Can you share finding and current status of project ?

Thx

Olivier