A/D Converter; Characteristics And Configuration Of A/D Converter; Terminal Configuration Of A/D Converter - Epson S1C63358 Technical Manual

4.10 A/D Converter

4.10.1 Characteristics and configuration of A/D converter

The S1C63358 has a built-in A/D converter with the following characteristics.
• Conversion method: Successive-approximation type
• Resolution:
• Input channels:
• Conversion time:
• Setting of analog conversion voltage range is possible with reference voltage terminal (AV
• A/D conversion result is possible to read from 8-bit data register
• Sample & hold circuit built-in
• A/D conversion completion generates an interrupt
Figure 4.10.1.1 shows the configuration of the A/D converter.
AV
DD
AV
REF
AV
SS
AD0 (P40)
AD1 (P41)
AD2 (P42)
AD3 (P43)

4.10.2 Terminal configuration of A/D converter

The terminals used with the A/D converter are as follows:
AV , AV (power supply terminal)
DD SS
The AV and AV terminals are power supply terminals for the A/D converter. The voltage should be
DD SS
≤ V
input as AV and AV
DD DD
AV (reference voltage input terminal)
REF
The AV terminal is the reference voltage terminal of the analog block. Input voltage range of the A/D
REF
conversion is decided by this input (AV
AD0–AD3 (analog input terminal)
The analog input terminals AD0–AD3 are shared with the I/O port terminals P40–P43. Therefore, it is
necessary to set them for the A/D converter by software when using them as analog input terminals. This
setting can be done for each terminal. (Refer to Section 4.10.4 for setting.)
At initial reset, all the terminals are set in the I/O port terminals.
Analog voltage value AV
S1C63358 TECHNICAL MANUAL
CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (A/D Converter)
8 bits
Maximum error: ±3 LSB, A/D clock: OSC1, OSC3, V
Maximum error: ±3 LSB, A/D clock: OSC1, OSC3 ≤ 2.5 MHz, V
Maximum error: ±5 LSB, A/D clock: OSC1, V
Maximum error: ±5 LSB, A/D clock: OSC1, V
Maximum 4 channels
Minimum 10.5 µsec (during operation at 2 MHz)
Minimum 641 µsec (during operation at 32.768 kHz)
8-bit
D/A converter
Analog
mux
OSC3
oscillator
OSC1
oscillator
Fig. 4.10.1.1 Configuration of A/D converter
= V .
SS SS
–AV
SS REF
that can be input is in the range of AV
IN
DD
DD
Converted
SAR
data
Comparator
+
–
Control
circuit
Sample & hold
f
f 2
OSC1
OSC3/
1/2
Clock
selector
f
OSC1
). The voltage should be input as AV
≤ AV
SS
EPSON
= 2.7 V to 3.6 V
DD
= 2.3 V to 2.7 V
DD
= 1.6 V to 2.3 V
= 0.9 V to 1.6 V
)
REF
Interrupt
circuit
or f 2
OSC3/
≤ AV
REF DD
≤ AV
.
IN REF
.
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