SH7706 Datasheet, PDF (595/749 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH™ RISC engine Family/SH7700 Series

Section 19 A/D Converter (ADC)
19.9.2 Processing of Analog Input Pins
To prevent damage from voltage surges at the analog input pins (AN0 to AN3), connect an input
protection circuit like the one shown in figure 19.11. The circuit shown also includes an RC filter
to suppress noise. This circuit is shown as an example; The circuit constants should be selected
according to actual application conditions. Table 19.4 lists the analog input pin specifications and
figure 19.12 shows an equivalent circuit diagram of the analog input ports.
AV_CC
100 Ω
SuperH microprocessor
AN0 to AN3
*
0.1 µF
AV_SS
Note: _*
10 µF
0.01 µF
Figure 19.11 Example of Analog Input Protection Circuit
AN0 to AN3
1.0 kΩ
20 pF
1 MΩ
Figure 19.12 Analog Input Pin Equivalent Circuit
Table 19.4 Analog Input Pin Ratings
Item
Min
Max
Unit
Analog input capacitance
—
20
pF
Allowable signal-source impedance
—
5
kΩ
Rev. 5.00 May 29, 2006 page 547 of 698
REJ09B0146-0500