HD6412332 RENESAS [Renesas Technology Corp], HD6412332 Datasheet - Page 746

• Manufacturer Part Number: HD6412332
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2300 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

16.6
The following points should be noted when using the A/D converter.
Setting Range of Analog Power Supply and Other Pins
1. Analog input voltage range
2. Relation between AV
3. V
If conditions 1, 2, and 3 above are not met, the reliability of the device may be adversely affected.
Notes on Board Design: In board design, digital circuitry and analog circuitry should be as
mutually isolated as possible, and layout in which digital circuit signal lines and analog circuit
signal lines cross or are in close proximity should be avoided as far as possible. Failure to do so
may result in incorrect operation of the analog circuitry due to inductance, adversely affecting A/D
conversion values.
Also, digital circuitry must be isolated from the analog input signals (AN0 to AN7 and AN12 to
AN15), analog reference power supply (V
ground (AV
digital ground (V
Notes on Noise Countermeasures: A protection circuit connected to prevent damage due to an
abnormal voltage such as an excessive surge at the analog input pins (AN0 to AN7 and AN12 to
AN15) and analog reference power supply (V
shown in figure 16.7.
Also, the bypass capacitors connected to AV
to AN7 must be connected to AV
If a filter capacitor is connected as shown in figure 16.7, the input currents at the analog input pins
(AN0 to AN7 and AN12 to AN15) are averaged, and so an error may arise. Also, when A/D
Rev.4.00 Sep. 07, 2007 Page 716 of 1210
REJ09B0245-0400
The voltage applied to analog input pins ANn during A/D conversion should be in the range
AV
As the relationship between AV
not used, the AV
The analog reference voltage input at the V
V
pin open.
ref
ref
SS
input range
pin should be set as V
≤ ANn ≤ V
Usage Notes
SS
). Also, the analog ground (AV
SS
) on the board.
CC
ref
and AV
.
CC
, AV
ref
SS
SS
= V
SS
pins must not be left open.
and V
.
CC
CC
, AV
when the A/D converter is not used. Do not leave the V
CC
ref
SS
, V
), and analog power supply (AV
CC
and V
SS
ref
SS
) should be connected at one point to a stable
ref
) should be connected between AV
and V
pin should be set in the range V
CC
, V
ref
and the filter capacitor connected to AN0
SS
, set AV
SS
= V
SS
. If the A/D converter is
CC
) by the analog
ref
CC
≤ AV
and AV
CC
. The
SS
ref
as