Datasheet

© 2011-2014 Microchip Technology Inc. DS60001168F-page 203
PIC32MX1XX/2XX
21.0 10-BIT ANALOG-TO-DIGITAL
CONVERTER (ADC)
The PIC32MX1XX/2XX 10-bit Analog-to-Digital
Converter (ADC) includes the following features:
• Successive Approximation Register (SAR)
conversion
• Up to 1 Msps conversion speed
• Up to 13 analog input pins
• External voltage reference input pins
• One unipolar, differential Sample and Hold
Amplifier (SHA)
• Automatic Channel Scan mode
• Selectable conversion trigger source
• 16-word conversion result buffer
• Selectable buffer fill modes
• Eight conversion result format options
• Operation during Sleep and Idle modes
A block diagram of the 10-bit ADC is illustrated in
Figure 21-1. Figure 21-2 illustrates a block diagram of
the ADC conversion clock period. The 10-bit ADC has
up to 13 analog input pins, designated AN0-AN12. In
addition, there are two analog input pins for external
voltage reference connections. These voltage
reference inputs may be shared with other analog input
pins and may be common to other analog module
references.
FIGURE 21-1: ADC1 MODULE BLOCK DIAGRAM
Note 1: This data sheet summarizes the features
of the PIC32MX1XX/2XX family of
devices. It is not intended to be a
comprehensive reference source. To
complement the information in this data
sheet, refer to Section 17. “10-bit
Analog-to-Digital Converter (ADC)”
(DS60001104) in the “PIC32 Family
Reference Manual”, which is available
from the Microchip web site
(www.microchip.com/PIC32).
2: Some registers and associated bits
described in this section may not be
available on all devices. Refer to
Section 4.0 “Memory Organization” in
this data sheet for device-specific register
and bit information.
SAR ADC
S&H
ADC1BUF0
ADC1BUF1
ADC1BUF2
ADC1BUFF
ADC1BUFE
CTMUT
(3)
IVREF
(4)
AN1
VREFL
CH0SB<4:0>
CH0NA CH0NB
+
-
CH0SA<4:0>
Channel
Scan
CSCNA
Alternate
V
REF+
(1)
AVDD AVSS
VREF-
(1)
Note 1: VREF+ and VREF- inputs can be multiplexed with other analog inputs.
2: AN8 is only available on 44-pin devices. AN6, AN7, and AN12 are not available on 28-pin devices.
3: Connected to the CTMU module. See Section 24.0 “Charge Time Measurement Unit (CTMU)” for more
information.
4: Internal precision voltage reference (1.2V).
5: This selection is only used with CTMU capacitive and time measurement.
Input Selection
V
REFH
VREFL
VCFG<2:0>
AN12
(2)
AN0
Open
(5)
CTMUI
(3)