A/D Converter Precautions - NEC mPD780208 Subseries User Manual

12.5 A/D Converter Precautions

(1) Power consumption in standby mode
The A/D converter operates on the main system clock. Therefore, its operation stops in STOP mode or
in HALT mode with the subsystem clock. As a current still flows in the AV
must be cut in order to minimize the overall system power consumption.
In this example, the power consumption can be reduced if a low level is output to the output port in the
standby mode. However, the actual AV
value is not accurate and should be used for relative comparison only.
Figure 12-8. Example of Method of Reducing Power Consumption in Standby Mode
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CHAPTER 12 A/D CONVERTER
voltage is not so accurate and, accordingly, the converted
REF
V
DD
Output port
AV
REF
AV = V
REF DD
Series resistor string
AV
SS
µ
PD780205
User's Manual U11302EJ4V0UM
pin at this time, this current
REF