Datasheet

1317
SAM3X / SAM3A [DATASHEET]
Atmel-11057C-ATARM-SAM3X-SAM3A-Datasheet_23-Mar-15
43. Analog-to-Digital Converter (ADC)
43.1 Description
The ADC is based on a 12-bit Analog-to-Digital Converter (ADC) managed by an ADC Controller. Refer to the
Block Diagram: Figure 43-1. It also integrates a 16-to-1 analog multiplexer, making possible the analog-to-digital
conversions of 16 analog lines. The conversions extend from 0V to ADVREF. The ADC supports an 10-bit or 12-
bit resolution mode, and conversion results are reported in a common register for all channels, as well as in a
channel-dedicated register. Software trigger, external trigger on rising edge of the ADTRG pin or internal triggers
from Timer Counter output(s) are configurable.
The comparison circuitry allows automatic detection of values below a threshold, higher than a threshold, in a
given range or outside the range, thresholds and ranges being fully configurable.
The ADC Controller internal fault output is directly connected to PWM Fault input. This input can be asserted by
means of comparison circuitry in order to immediately put the PWM outputs in a safe state (pure combinational
path).
The ADC also integrates a Sleep Mode and a conversion sequencer and connects with a PDC channel. These
features reduce both power consumption and processor intervention.
This ADC has a selectable single-ended or fully differential input and benefits from a 2-bit programmable gain. A
whole set of reference voltages is generated internally from a single external reference voltage node that may be
equal to the analog supply voltage. An external decoupling capacitance is required for noise filtering.
A digital error correction circuit based on the multi-bit redundant signed digit (RSD) algorithm is employed in order
to reduce INL and DNL errors.
Finally, the user can configure ADC timings, such as Startup Time and Tracking Time.