Power Supplies; Introduction; Independent A/D Converter Supply And Reference Voltage; Figure 1. Power Supply Overview - ST STM32F10 Series Application Note

2

Power supplies

2.1

Introduction

The device requires a 2.0 to 3.6 V operating voltage supply (V
is used to supply the internal 1.8 V digital power.
The real-time clock (RTC) and backup registers can be powered from the V
when the main V
Note: V and V
DDA
2.1.1

Independent A/D converter supply and reference voltage

To improve the conversion accuracy, the ADC has an independent power supply that can be
filtered separately, and shielded from noise on the PCB:
•
the ADC voltage supply input is available on a separate V
•
an isolated supply ground connection is provided on the V
When available (depending on package), V
On 100- and 144-pin packages
To ensure a better accuracy on low-voltage inputs, the user can connect a separate external
reference voltage ADC input on V
supply is powered off.
DD

Figure 1. Power supply overview

(V ) V
SSA REF–
(from 2.4 V up to V ) V
DDA REF+
(V ) V
DD DDA
(V ) V
SS SSA
V
SS
V
DD
(V ) V
DD BAT
must be connected, respectively, to V
SSA
V domain
DDA
A/D converter
Temp. sensor
Reset block
PLL
V domain
DD
I/O Ring
Standby circuitry
(Wakeup logic,
IWDG)
Voltage regulator
Low voltage detector
Backup domain
LSE crystal 32 KHz oscillator
BKP registers
RCC BDCR register
RTC
DD
must be tied to V
REF–
. The voltage on V
REF+
AN2586 Rev 8
Power supplies
). An embedded regulator
DD
BAT
1.8 V domain
Core
memories'
digital
peripherals
and V .
SS
pin
DDA
pin
SSA
.
SSA
can range from 2.4 V to V
REF+
voltage
ai14863
.
DDA
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