Precision ADC Introduction
843
SLAU356I – March 2015 – Revised June 2019
Copyright © 2015–2019, Texas Instruments Incorporated
Precision ADC
22.1 Precision ADC Introduction
The Precision ADC module is a native 14-bit SAR analog-to-digital conversions, supports up to 16-bit
precision through software over-sampling. The module implements a 14-bit SAR core, sample select
control, and up to 32 independent conversion-and-control buffers. The conversion-and-control buffer
allows up to 32 independent analog-to-digital converter (ADC) samples to be converted and stored without
any CPU intervention.
Precision ADC features include:
•
1-Msps maximum conversion rate at maximum resolution of 14 bits
•
Monotonic 14-bit converter with no missing codes
•
Sample-and-hold with programmable sampling periods controlled by software or timers
•
Conversion initiation by software or timers
•
Software-selectable on-chip reference voltage generation (1.2 V, 1.45 V, or 2.5 V) with option to make
available externally
•
Software-selectable internal or external reference
•
Up to 32 individually configurable external input channels, single-ended or differential input selection
available
•
Internal conversion channels for internal temperature sensor and ½ AV
CC
and four more internal
channels available on select devices (see device data sheet for availability and function)
•
Independent channel-selectable reference sources for positive reference
•
Selectable conversion clock source
•
Single-channel, repeat-single-channel, sequence (autoscan), and repeat-sequence (repeated
autoscan) conversion modes
•
Interrupt vector register for fast decoding of 38 ADC interrupts
•
32 conversion-result storage registers
•
Window comparator for low power monitoring of input signals of conversion-result registers
shows the block diagram of Precision ADC. The reference generation is located in the
reference module (REF).