R01UH0822EJ0100 Rev.1.00
Page 881 of 1041
Jul 31, 2019
RX13T Group
26. 12-Bit A/D Converter (S12ADF)
26.6.9
Voltage Range of Analog Power Supply Pins
If this MCU is used with the voltages outside the following ranges, the reliability of the MCU may be affected.
Analog input voltage range
Voltage applied to analog input pins AN000 to AN007: AVSS0 ≤ VAN0 ≤ AVCC0
Relationship between power supply pin pairs (AVCC0–AVSS0, VCC–VSS)
The following condition should be satisfied: AVSS0 = VSS.
A 0.1-μF capacitor should be connected between each pair of power supply pins to create a closed loop with the
shortest route possible as shown in
, and connection should be made so that the following condition is
satisfied at the supply side: AVSS0 = VSS
When the 12-bit A/D converter is not used, the following conditions should be satisfied:
AVCC0 = VCC and AVSS0 = VSS
Figure 26.34
Power Supply Pin Connection Example
26.6.10
Notes on Board Design
The board should be designed so that digital circuits and analog circuits are separated from each other as far as possible.
In addition, digital circuit signal lines and analog circuit signal lines should not intersect or placed near each other. If
these rules are not followed, noise will be produced on analog signals and A/D conversion accuracy will be affected. The
analog input pins (AN000 to AN007), and analog power supply (AVCC0) should be separated from digital circuits using
the analog ground (AVSS0). The analog ground (AVSS0) should be connected to a stable digital ground (VSS) on the
board (single-point ground plane connection).
0.1µF
0.1µF
VCC
VSS
AVCC0
AVSS0