A/D Converter Cautions; Example Of Method Of Reducing Current Dissipation In Standby Mode - NEC PD78052 User Manual

14.5 A/D Converter Cautions

(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
be cut in order to minimize the overall system power dissipation. In Figure 14-10, the power dissipation can
be reduced by outputting a low-level signal to the output port in standby mode. However, there is no precision
to the actual AV
REF0
used for relative comparison.
Figure 14-10. Example of Method of Reducing Current Dissipation in Standby Mode
(2) Input range of ANI0 to ANI7
The input voltages of ANI0 to ANI7 should be within the specification range. In particular, if a voltage above
AV or below AV
REF0 SS
that channel will be indeterminate. The conversion values of the other channels may also be affected.
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CHAPTER 14 A/D CONVERTER
voltage, and therefore the conversion values themselves lack precision and can only be
V
DD
Output Port
AV
REF0
. .
AV = V
REF0 DD
AV
SS
is input (even if within the absolute maximum rating range), the conversion value for
pin at this time, this current must
REF0
PD78054, 78054Y
Series Resistor String