Renesas SH7041 Series, Hardware Manual, Page: 622 / 923

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16.7 Usage Notes
The following points should be noted when using the mid-speed A/D converter.
16.7.1 Analog Voltage Settings
(1) Analog input voltage range
The voltage applied to analog input pins during A/D conversion should be in the range AVSS
≤
ANn
≤
AV
ref
(n = 0 to 7).
(2) AV
CC
and AV
SS
input voltages
For the AV
CC
and AV
SS
input voltages, set AV
CC
= V
CC
±10% and AV
SS
= V
SS
. When the
medium-speed A/D converter is not used, set AV
CC
= V
CC
and AV
SS
= V
SS
.
(3) AVref input voltage
For the AV
ref
pin input voltage analog reference, set AV
ref
≤
AV
CC
. When the medium-speed
A/D converter is not used, set AV
ref
= AV
CC
.
(4) AV
CC
and AV
ref
must be connected to the power supply (V
CC
) even if the medium-speed A/D
converter is not used or is in standby mode.
16.7.2 Handling of Analog Input Pins
To prevent damage from surges and other abnormal voltages at the analog input pins (AN0-AN7),
connect a protection circuit such as that shown in figure 16.8. This circuit also includes a CR filter
function that suppresses error due to noise. The circuit shown here is only a design example;
circuit constants must be decided on the basis of the actual operating conditions.
Figure 16.9 shows an equivalent circuit for the analog input pins, and table 16.6 summarizes the
analog input pin specifications.