Datasheet

914
SAM9G35 [DATASHEET]
11053E–ATARM–10-Mar-2014
41. Analog-to-Digital Converter (ADC)
41.1 Description
The ADC is based on a 10-bit Analog-to-Digital Converter (ADC) managed by an ADC Controller. Refer to the Block
Diagram: Figure 41-1. It also integrates a 12-to-1 analog multiplexer, making possible the analog-to-digital conversions
of 12 analog lines. The conversions extend from 0V to ADVREF. The ADC supports an 8-bit or 10-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 also integrates a Sleep Mode and a conversion sequencer and connects with a DMA channel. These features
reduce both power consumption and processor intervention.
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.
Finally, the user can configure ADC timings, such as Startup Time and Tracking Time.
This ADC Controller includes a Resistive Touchscreen Controller. It supports 4-wire and 5-wire technologies.
41.2 Embedded Characteristics
 10-bit Resolution
 440 kHz Conversion Rate
 Wide Range Power Supply Operation
 Resistive 4-wire and 5-wire Touchscreen Controller
 Position and Pressure Measurement for 4-wire screens
 Position Measurement for 5-wire screens
 Average of up to 8 measures for noise filtering
 Programmable Pen Detection sensitivity
 Integrated Multiplexer Offering Up to 12 Independent Analog Inputs
 Individual Enable and Disable of Each Channel
 Hardware or Software Trigger
 External Trigger Pin
 Internal Trigger Counter
 Trigger on Pen Contact Detection
 DMA Support
 Possibility of ADC Timings Configuration
 Two Sleep Modes and Conversion Sequencer
 Automatic Wakeup on Trigger and Back to Sleep Mode after Conversions of all Enabled Channels
 Possibility of Customized Channel Sequence
 Standby Mode for Fast Wakeup Time Response
 Power Down Capability
 Automatic Window Comparison of Converted Values
 Write Protect Registers