H8S18 Datasheet, PDF (605/758 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2200 Series

Section 15 A/D Converter
15.8.4 Range of Analog Power Supply and Other Pin Settings
If the conditions below are not met, the reliability of the device may be adversely affected.
• Analog input voltage range
The voltage applied to analog input pin ANn during A/D conversion should be in the range
VSS ≤ ANn ≤ Vref.
• Vref input range
The analog reference voltage input at the Vref pin set is the range Vref ≤ Vcc.
15.8.5 Notes on Board Design
Careful consideration is required in board design for noise countermeasures and in order to prevent
damage due to abnormal voltage, such as an excessive surge at the analog input pins (AN0 to AN3
or AN14 to AN15) and analog reference voltage pin (Vref).
Table 15.6 Analog Pin Specifications
Item
Analog input capacitance
Permissible signal source impedance
Note: * Vcc = 2.7 to 3.6 V
Min.
—
—
Max.
Unit
20
pF
5*
kΩ
10 kΩ
ANn
To A/D converter
20 pF
Note: Values are reference values.
Figure 15.10 Analog Input Pin Equivalent Circuit
Rev.7.00 Dec. 24, 2008 Page 549 of 698
REJ09B0074-0700