Freescale Semiconductor MCF52211 ユーザーズマニュアル
Analog-to-Digital Converter (ADC)
MCF52211 ColdFire® Integrated Microcontroller Reference Manual, Rev. 2
26-38
Freescale Semiconductor
V
REFH
is as noise-free as possible. Any noise residing on the V
REFH
voltage is directly transferred to the
digital result.
illustrates the internal workings of the ADC voltage reference circuit. V
REFH
must be noise
filtered; a minimum configuration is shown in the figure.
26.5.11 Supply Pins V
DDA
and V
SSA
Dedicated power supply pins are provided for the purposes of reducing noise coupling and to improve
accuracy. The power provided to these pins is suggested to come from a low noise filtered source.
Uncoupling capacitors ought to be connected between V
accuracy. The power provided to these pins is suggested to come from a low noise filtered source.
Uncoupling capacitors ought to be connected between V
DDA
and V
SSA
.