SH7206 Datasheet, PDF (882/1188 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7200 Series

Section 17 A/D Converter (ADC)
17.7 Usage Notes
When using the A/D converter, note the following points.
17.7.1 Module Standby Mode Setting
Operation of the A/D converter can be disabled or enabled using the standby control register. The
initial setting is for operation of the A/D converter to be halted. Register access is enabled by
clearing module standby mode. For details, see section 22, Power-Down Modes.
17.7.2 Setting Analog Input Voltage
Permanent damage to the LSI may result if the following voltage ranges are exceeded.
1. Analog input range
During A/D conversion, voltages on the analog input pins ANn should not go beyond the
following range: AVss ≤ ANn ≤ AVcc (n = 0 to 7).
2. AVcc and AVss input voltages
Input voltages AVcc and AVss should be PVcc − 0.3 V ≤ AVcc ≤ PVcc and AVss = PVss. Do
not leave the AVcc and AVss pins open when the A/D converter or D/A converter is not in use
and in software standby mode. When not in use, connect AVcc to the power supply (PVcc) and
AVss to the ground (PVss).
3. Setting range of AVref input voltage
Set the reference voltage range of the AVref pin as 3.0 V ≤ AVref ≤ AVcc.
17.7.3 Notes on Board Design
In board design, digital circuitry and analog circuitry should be as mutually isolated as possible,
and layout in which digital circuit signal lines and analog circuit signal lines cross or are in close
proximity should be avoided as far as possible. Failure to do so may result in incorrect operation
of the analog circuitry due to inductance, adversely affecting A/D conversion values.
Digital circuitry must be isolated from the analog input signals (AN0 to AN7), analog reference
voltage (AVref), and analog power supply (AVcc) by the analog ground (AVss). Also, the analog
ground (AVss) should be connected at one point to a stable digital ground (PVss) on the board.
Rev. 3.00 Jun. 18, 2008 Page 858 of 1160
REJ09B0191-0300