HD64F2149 Datasheet, PDF (681/1035 Pages) Renesas Technology Corp – Hitachi 16-Bit Single-Chip Microcomputer

sample-and-hold circuit in the A/D converter exceeds the current input via the input impedance
(R_in), an error will arise in the analog input pin voltage. Careful consideration is therefore required
when deciding the circuit constants.
*¹
*¹
R_in* ²
100 Ω
0.1 µF
Notes: Figures are reference values.
1.
10 µF
0.01 µF
AVCC
AVref
AN0 to AN7
AVSS
2. R_in: Input impedance
Figure 20.7 Example of Analog Input Protection Circuit
Table 20.5 Analog Pin Ratings
Item
Min
Max
Unit
Analog input capacitance
—
20
pF
Permissible signal source impedance
—
5*
kΩ
Note: * When V_CC= 2.7 to 3.6 V and ø ≤ 10 MHz.
AN0 to AN7
10 kΩ
To A/D converter
20 pF
Note: Numeric values are reference values.
Figure 20.8 Analog Input Pin Equivalent Circuit
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