17 12-BIT A/D CONVERTER (ADC12A)
S1C17M12/M13 TECHNICAL MANUAL
Seiko Epson Corporation
17-1
(Rev. 1.2)
17 12-bit A/D Converter (ADC12A)
17.1 Overview
The ADC12A is a successive approximation type 12-bit A/D converter.
The features of the ADC12A are listed below.
• Conversion method:
Successive approximation type
• Resolution:
12 bits
• Analog input voltage range:
Reference voltage VREFA to V
SS
• Supports two conversion modes: 1. One-time conversion mode
2. Continuous conversion mode
• Supports three conversion triggers: 1. Software trigger
2. 16-bit timer underflow trigger
3. External trigger
• Can convert multiple analog input signals sequentially.
• Can generate conversion completion and overwrite error interrupts.
Figure 17.1.1 shows the ADC12A configuration.
Table 17.1.1 ADC12A Configuration of S1C17M12/M13
Item
S1C17M12
S1C17M13
Number of channels
–
1 channel (Ch.0)
Number of analog signal inputs per channel
Ch.0: 8 inputs (ADIN00–ADIN07)
16-bit timer used as conversion clock and trigger sources
Ch.0
←
16-bit timer Ch.3
VREFA pin (external reference voltage input)
Available
ADC12A Ch.n
Trigger
select circuit
Successive
approximation
control circuit
CNVTRG[1:0]
CNVMD
MODEN
ADST
STMD
AD0D[15:0]
ADSTAT[2:0]
BSYSTAT
AD1D[15:0]
ADmD[15:0]
SMPCLK[2:0]
VRANGE[1:0]
#ADTRGn
ADINn0
ADINn1
ADINnm
VREFAn
Interrupt
control
circuit
AD0CIF
AD1CIF
ADmCIF
AD0OVIF
AD1OVIF
ADmOVIF
AD0CIE
AD1CIE
ADmCIE
AD0OVIE
AD1OVIE
ADmOVIE
Interrupt
controller
Inter
nal data
bu
s
Timer
16-bit timer
Ch.k
Underflow
Clock
generator
CLK_T16_k
MUX
+
–
Comparator with
sample & hold circuit
D/A
converter
Figure 17.1.1 ADC12A Configuration
Note: In this chapter, n, m, and k refer to an ADC12A channel number, an analog input pin number, and
a 16-bit timer channel number, respectively.