FS45 VCCA without capacitor will cause RSTB cannot pull High

[Eason_L]

Hi,

I don't need VCCA feature, here's my circuit. After testing, it requires a capacitor connect VCCA to GND, so that it can work properly. What's the possible reason may cause this issue? 

[guoweisun]

HI 

VCCA本质上是个LDO，LDO最小系统是由CIN/COUT 组成的，假如缺少了COUT LDO 便不能正常工作，FS也会报错，另外：

VCCA is a linear voltage regulator mainly dedicated to supplying the MCU I/Os, especially
the ADC reference voltage.