HD6413008F RENESAS [Renesas Technology Corp], HD6413008F Datasheet - Page 472

• Manufacturer Part Number: HD6413008F
• Description: Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series
• Manufacturer: RENESAS [Renesas Technology Corp]

14. A/D Converter
14.6
When using the A/D converter, note the following points:
1. Analog Input Voltage Range
2. Relationships of AV
3. V
4. Note on Board Design
5. Note on Noise
Rev.4.00 Aug. 20, 2007 Page 428 of 638
REJ09B0395-0400
During A/D conversion, the voltages input to the analog input pins AN
AV
AV
left open, even if the A/D converter is not used.
The reference voltage input at the V
In board layout, separate the digital circuits from the analog circuits as much as possible.
Particularly avoid layouts in which the signal lines of digital circuits cross or closely approach
the signal lines of analog circuits. Induction and other effects may cause the analog circuits to
operate incorrectly, or may adversely affect the accuracy of A/D conversion.
The analog input signals (AN
voltage (AV
analog ground (AV
board.
To prevent damage from surges and other abnormal voltages at the analog input pins (AN
AN
14.7 between AV
capacitors connected to AN
ones in figure 14.7 are connected, the voltage values input to the analog input pins (AN
AN
frequently performed in scan mode so that the current that charges and discharges the capacitor
in the sample-and-hold circuit of the A/D converter becomes greater than that input to the
analog input pins via input impedance (Rin). The circuit constants should therefore be selected
carefully.
REF
SS
CC
7
7
) and analog reference voltage pin (V
) will be smoothed, which may give rise to error. Error can also occur if A/D conversion is
Programming Range
, AV
≤ AN
Usage Notes
SS
n
, V
CC
≤ V
) must be separated from digital circuits by the analog ground (AV
CC
REF
, and V
CC
.
SS
and AV
CC
) should be connected to a stable digital ground (V
and AV
SS
should be related as follows: AV
SS
0
to AN
. The bypass capacitors connected to AV
0
SS
to AN
to V
7
REF
must be connected to AV
7
CC
), analog reference voltage (V
pin should be in the range V
and V
REF
), connect a protection circuit like the one in figure
SS
SS
= V
SS
. If filter capacitors like the
SS
. AV
REF
REF
), and analog supply
CC
≤ AV
CC
n
SS
should be in the range
and V
and AV
) at one point on the
CC
.
REF
SS
SS
and the filter
). The
must not be
0
to
0
to