Datasheet

 2009-2012 Microchip Technology Inc. DS70591E-page 309
dsPIC33FJ32GS406/606/608/610 and dsPIC33FJ64GS406/606/608/610
22.0 HIGH-SPEED, 10-BIT
ANALOG-TO-DIGITAL
CONVERTER (ADC)
The dsPIC33FJ32GS406/606/608/610 and
dsPIC33FJ64GS406/606/608/610 devices provide
high-speed successive approximation Analog-to-Digital
conversions to support applications such as AC/DC and
DC/DC power converters.
22.1 Features Overview
The ADC module incorporates the following features:
• 10-Bit Resolution
• Unipolar Inputs
• Up to Two Successive Approximation Registers
(SARs)
• Up to 24 External Input Channels
• Two Internal Analog Inputs
• Dedicated Result Register for each Analog Input
• ±1 LSB Accuracy at 3.3V
• Single Supply Operation
• 4 Msps Conversion Rate at 3.3V (devices with two
SARs)
• 2 Msps Conversion Rate at 3.3V (devices with
one SAR)
• Low-Power CMOS Technology
22.2 Module Description
This ADC module is designed for applications that
require low latency between the request for conversion
and the resultant output data. Typical applications
include:
• AC/DC Power Supplies
• DC/DC Converters
• Power Factor Correction (PFC)
This ADC works with the High-Speed PWM module in
power control applications that require high-frequency
control loops. This module can Sample-and-Convert
two analog inputs in a 0.5 microsecond when two SARs
are used. This small conversion delay reduces the
“phase lag” between measurement and control system
response.
Up to five inputs may be sampled at a time (four inputs
from the dedicated sample and hold circuits and one
from the shared sample and hold circuit). If multiple
inputs request conversion, the ADC will convert them in
a sequential manner, starting with the lowest order
input.
This ADC design provides each pair of analog inputs
(AN1, AN0), (AN3, AN2),..., the ability to specify its own
trigger source out of a maximum of sixteen different
trigger sources. This capability allows this ADC to Sam-
ple-and-Convert analog inputs that are associated with
PWM generators operating on independent time
bases.
The user application typically requires synchronization
between analog data sampling and PWM output to the
application circuit. The very high-speed operation of
this ADC module allows “data on demand”.
In addition, several hardware features have been
added to the peripheral interface to improve real-time
performance in a typical DSP-based application.
• Result Alignment Options
• Automated Sampling
• External Conversion Start Control
• Two Internal Inputs to Monitor the INTREF and
EXTREF Input Signals
Block diagrams of the ADC module for the family
devices are shown in Figure 22-1 through Figure 22-4.
Note 1: This data sheet summarizes the features
of the dsPIC33FJ32GS406/606/608/610
and dsPIC33FJ64GS406/606/608/610
families of devices. It is not intended to
be a comprehensive reference source.
To complement the information in this
data sheet, refer to Section 44.
“High-Speed 10-Bit Analog-to-Digital
Converter (ADC)” (DS70321) in the
“dsPIC33F/PIC24H Family Reference
Manual”, which is available from the
Microchip web site (www.microchip.com).
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.