h8s-2169 Renesas Electronics Corporation., h8s-2169 Datasheet - Page 707

• Manufacturer Part Number: h8s-2169
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

If a filter capacitor is connected as shown in figure 20.7, the input currents at the analog input pins
(AN0 to AN7) are averaged, and so an error may arise. Also, when A/D conversion is performed
frequently, as in scan mode, if the current charged and discharged by the capacitance of the
sample-and-hold circuit in the A/D converter exceeds the current input via the input impedance
(R
when deciding the circuit constants.
Table 20.5 Analog Pin Ratings
Note:
Item
Analog input capacitance
Permissible signal source impedance
in
), an error will arise in the analog input pin voltage. Careful consideration is therefore required
Notes:
*
* When V
1
Figures are reference values.
1.
2. R
*
1
10 µF
in
Figure 20.7 Example of Analog Input Protection Circuit
CC
: Input impedance
= 2.7 to 3.6 V and
R
in
*
2
0.01 µF
100
0.1 µF
10 MHz.
Min
—
—
AVCC
AVref
AN0 to AN7
AVSS
Rev. 3.00 Jan 18, 2006 page 679 of 1044
Max
20
5 *
Section 20 A/D Converter
REJ09B0280-0300
Unit
pF
k