LM3S5P3B Datasheet, PDF (541/1170 Pages) Texas Instruments – Stellaris® LM3S5P3B Microcontroller

Stellaris^® LM3S5P3B Microcontroller
12
Analog-to-Digital Converter (ADC)
An analog-to-digital converter (ADC) is a peripheral that converts a continuous analog voltage to a
discrete digital number. Two identical converter modules are included, which share 16 input channels.
The Stellaris^® ADC module features 10-bit conversion resolution and supports 16 input channels,
plus an internal temperature sensor. Each ADC module contains four programmable sequencers
allowing the sampling of multiple analog input sources without controller intervention. Each sample
sequencer provides flexible programming with fully configurable input source, trigger events, interrupt
generation, and sequencer priority. A digital comparator function is included which allows the
conversion value to be diverted to a digital comparator module. Each ADC module provides eight
digital comparators. Each digital comparator evaluates the ADC conversion value against its two
user-defined values to determine the operational range of the signal. The trigger source for ADC0
and ADC1 may be independent or the two ADC modules may operate from the same trigger source
and operate on the same or different inputs. A phase shifter can delay the start of sampling by a
specified phase angle. When using both ADC modules, it is possible to configure the converters to
start the conversions coincidentally or within a relative phase from each other, see “Sample Phase
Control” on page 547.
The Stellaris LM3S5P3B microcontroller provides two ADC modules with each having the following
features:
■ 16 shared analog input channels
■ Single-ended and differential-input configurations
■ On-chip internal temperature sensor
■ Maximum sample rate of one million samples/second
■ Optional phase shift in sample time programmable from 22.5º to 337.5º
■ Four programmable sample conversion sequencers from one to eight entries long, with
corresponding conversion result FIFOs
■ Flexible trigger control
– Controller (software)
– Timers
– Analog Comparators
– PWM
– GPIO
■ Hardware averaging of up to 64 samples
■ Digital comparison unit providing eight digital comparators
■ Converter uses an internal 3-V reference or an external reference
■ Power and ground for the analog circuitry is separate from the digital power and ground
January 20, 2012
541
Texas Instruments-Production Data