HD64F2636F20 Datasheet, PDF (754/1512 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2600 Series

Section 17 A/D Converter
H8S/2639, H8S/2638, H8S/2636,
H8S/2630, H8S/2635 Group
Influences on Absolute Precision: Adding capacitance results in coupling with GND, and
therefore noise in GND may adversely affect absolute precision. Be sure to make the connection to
an electrically stable GND such as AVSS.
Care is also required to insure that filter circuits do not communicate with digital signals on the
mounting board, so acting as antennas.
Figure 17-11 shows an example of analog input circuit.
Sensor output
impedance
to 5 kΩ
Sensor input
Low-pass
filter
C to 0.1 μF
Chip
C_in =
15 pF
A/D converter
equivalent circuit
10 kΩ
20 pF
Figure 17-11 Example of Analog Input Circuit
Page 704 of 1458
REJ09B0103-0800 Rev. 8.00
May 28, 2010