VDDA為所有的模擬電路部分供電,包括:
ADC模塊,復位電路,PVD(可編程電壓監(jiān)測器),PLL,上電復位(POR)和掉電復位(PDR)模塊,控制VBAT切換的開關(guān)等。即使不 使用ADC功能,也需要連接VDDA,強烈建議VDD和VDDA使用同一個電源供電。VDD與VDDA之間的電壓差不能超過300mV,VDD與VDDA 應該同時上電或調(diào)電。
VDDA,VSSA是模擬部分的電源,因為它連接著復位電路,所以這個必須接,否則無法下載代碼。
Power supply schemes(供電方案)
?VDD = 2.0 to 3.6 V:external power supply for I/Os and the internal regulator. Provided externally through VDD pins.
? VSSA, VDDA = 2.0 to 3.6 V:external analog power supplies for ADC, reset blocks, RCs and PLL (minimum voltage to be applied to VDDA is 2.4 V when the ADC is used). VDDA and VSSA must be connected to VDD and VSS, respectively.
? VBAT = 1.8 to 3.6 V:power supply for RTC, external clock 32 kHz oscillator and backup registers (through power switch) when VDD is not present.