ST STM32L152-EVAL Application Note

AN3216 Power supplies
Doc ID 17496 Rev 5 7/30
2.1.1 Independent A/D converter supply and reference voltage
To improve conversion accuracy, the ADC and the DAC have 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
DDA
pin
● An isolated supply ground connection is provided on the V
SSA
pin
V
DDA
and V
REF
require a stable voltage. The consumption on V
DDA
can reach several mA
(see I
DD
(ADCx), I
DD
(DAC), I
DD
(COMPx), I
VDDA
, and I
VREF
in the product datasheets for
further information).
When available (depending on the package), V
REF¨
must be tied to V
SSA
.
On BGA 64-pin and all 100-pin packages
To ensure a better accuracy on low-voltage inputs and outputs, the user can connect to
V
REF+
, a separate external reference voltage which is lower than V
DD
. V
REF+
is the highest
voltage, represented by the full scale value, for an analog input (ADC) or output (DAC)
signal.
● For ADC
– 2.4 V ≤ V
REF+
= V
DDA
for full speed (ADCCLK = 16 MHz, 1 Msps)
– 1.8 V ≤ V
REF+
= V
DDA
for medium speed (ADCCLK = 8 MHz, 500 Ksps)
– 2.4 V ≤ V
REF+
≠ V
DDA
for medium speed (ADCCLK = 8 MHz, 500 Ksps)
– 1.8 V ≤ V
REF+
< V
DDA
for low speed (ADCCLK = 4 MHz, 250 Ksps)
– When product voltage range 3 is selected (V
CORE
= 1.2 V), the ADC is low speed
(ADCCLK = 4 MHz, 250 Ksps)
● For DAC
– 1.8 V≤ V
REF+
< V
DDA
On packages with 64 pins or less (except BGA package)
V
REF+
and V
REF-
pins are not available. They are internally connected to the ADC voltage
supply (V
DDA
) and ground (V
SSA
).

ST STM32L152-EVAL Specifications

General

Brand	ST
Model	STM32L152-EVAL
Category	Motherboard
Language	English