Clock
Bus[7:0]
Size
R/W
Int
15:8
Int
7:0
Ready
Ready
Digital Buffer
Analog Buffer
Sync
Stall
Analog-to-Digital Converter (ADC)
859
SPRUH22I – April 2012 – Revised November 2019
Copyright © 2012–2019, Texas Instruments Incorporated
Analog Subsystem
Figure 10-9. ADC Interrupt
10.3
Analog-to-Digital Converter (ADC)
The ADC module described in this reference guide is a 12-bit recyclic ADC; part SAR, part pipelined. The
analog circuits of this converter, referred to as the "core" in this document, include the front-end analog
multiplexers (MUXs), sample-and-hold (S/H) circuits, the conversion core, voltage regulators, and other
analog supporting circuits. Digital circuits, referred to as the "wrapper" in this document, include
programmable conversions, result registers, interface to analog circuits, interface to the Analog Common
Interface Bus (ACIB), and interface to other on-chip modules.
10.3.1 Features
The core of the ADC contains a single 12-bit converter fed by two sample and hold circuits. The sample
and hold circuits can be sampled simultaneously or sequentially. These, in turn, are fed by a total of up to
16 analog input channels. See the device datasheet for the specific number of channels available. The
converter can be configured to run with an internal bandgap reference to create true-voltage based
conversions or with a pair of external voltage references (VREFHI/LO) to create ratiometric based
conversions.
Contrary to previous ADC types, this ADC is not sequencer based. It is easy for the user to create a
series of conversions from a single trigger. However, the basic principle of operation is centered around
the configurations of individual conversions, called SOC’s, or start-of-conversions.
Functions of each ADC module include:
•
12-bit ADC core with built-in dual sample-and-hold (S/H)
•
Simultaneous sampling or sequential sampling modes
•
Full range analog input: 0 V to 3.3 V fixed, or VREFHI/VREFLO ratiometric
•
Up to 16-channel, multiplexed inputs
•
16 SOC’s, configurable for trigger, sample window, and channel
•
16 result registers (individually addressable) to store conversion values
•
Multiple trigger sources
–
S/W - software immediate start
–
ePWM 1-9
–
External GPIO
–
CPU Timers 0/1/2
–
ADCINT1/2
•
8 flexible PIE interrupts total for both ADC modules, can configure interrupt request after any
conversion
•
8 flexible NVIC interrupts total for both ADC modules, can configure interrupt request after any
conversion