SH7205 Datasheet, PDF (1090/1904 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7200 Series

Section 21 A/D Converter (ADC)
Sensor input
Sensor output impedance
Up to 5 kΩ
Low-pass filter
C to 0.1 µF
This LSI
Cin =
15 pF
A/D converter
equivalent circuit
3 kΩ
20 pF
Note: Values are reference values.
Figure 21.10 Example of Analog Input Circuit
21.7.6 Influences on Absolute Precision
Adding capacitance results in coupling with GND, and therefore noise in GND may adversely
affect absolute precision. Be sure to connect AVss, etc. to an electrically stable GND.
Care is also required to insure that filter circuits do not communicate with digital signals on the
mounting board (i.e., acting as antennas).
21.7.7 A/D Conversion in Deep Standby Mode
Before entering deep standby mode, disable A/D conversion by clearing the SDST bit to 0. If the
LSI enters deep standby mode with A/D conversion enabled, the states on the A/D converter pins
are not guaranteed.
21.7.8 Usage Notes in Scan Mode or Multi Mode
When A/D conversion is restarted immediately after the mode of conversion has been changed
from scan mode or multi mode to single mode, the result of conversion in single mode may be
erroneous. After having set the ADST bit to 0, only initiate continuous conversion in single mode
by setting the ADST bit to 1 after having allowed the conversion time for a single channel to
elapse (the conversion time for a single channel differs from the time corresponding to the register
setting for A/D conversion frequency).
Rev. 1.00 Mar. 25, 2008 Page 1058 of 1868
REJ09B0372-0100