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GD32A50x User Manual
98
Figure 3-4. Waveform of the LVD threshold
V
DD
/ V
DDA
LVD output
t
LVD
threshold
100mV
V
hyst
Figure 3-5. Waveform of the OVD threshold
V
DD
/V
DDA
OVD output
t
OVD
threshold
25mV
V
hyst
Generally, digital circuits are powered by V
DD
, while most of analog circuits are powered by
V
DDA
. To improve the conversion accuracy of ADC and DAC, the independent power supply
V
DDA
is implemented to achieve better performance of analog circuits. V
DDA
can be externally
connected to V
DD
through the external filtering circuit to avoid noise on V
DDA
, and V
SSA
should
be connected to V
SS
through the specific circuit independently. Otherwise, if V
DDA
is different
from V
DD
, V
DDA
must always be higher, and the voltage difference should not exceed 0.3V.
To ensure a high accuracy on ADC and DAC, the ADC / DAC independent external reference
voltage should be connected to V
REF+
/ V
REF-
pins. According to the different packages, V
REF+
pin can be connected to V
DDA
pin, or external reference voltage which refers to
, V
REF-
pin must be connected to V
SSA
pin.