RM0090: Reference manual - STMicroelectronics

Power control (PWR) RM0090
Figure 7. Power supply overview
15 × 100 nF
+ 1 × 4.7 μF
V DD
100 nF
+ 1 μF
VBAT =
1.65 to 3.6V
V DD
100 nF
+ 1 μF
2 × 2.2 μF
V REF
V BAT
GP I/Os
V CAP_1
V CAP_2
V DD
1/2/...14/15
V SS
1/2/...14/15
BYPASS_REG
PDR_ON
V DDA
V REF+
V REF-
V SSA
Power switch
1. V DDA and V SSA must be connected to V DD and V SS , respectively.
5.1.1 Independent A/D converter supply and reference voltage
OUT
Voltage
regulator
Reset
controller
ADC
To improve conversion accuracy, the ADC has an independent power supply which can be
separately filtered and shielded from noise on the PCB.
● The ADC voltage supply input is available on a separate VDDA pin.
● An isolated supply ground connection is provided on pin VSSA .
To ensure a better accuracy of low voltage inputs, the user can connect a separate external
reference voltage ADC input on V REF . The voltage on V REF ranges from 1.8 V to V DDA .
91/1416 Doc ID 018909 Rev 3
Level shifter
Backup circuitry
(OSC32K,RTC,
Wakeup logic
Backup registers,
backup RAM)
IO
Logic
IN Kernel logic
(CPU,
digital
& RAM)
Analog:
RCs, PLL,
...
Flash memory
MS19911V2