43 ADC - Analog-to-Digital Converter with Computation and Context Module

The Analog-to-Digital Converter with Computation and Context module allows conversion of an analog input signal to a 12-bit binary representation of that signal. This device uses analog inputs that are multiplexed into a single Sample-and-Hold circuit. The output of the Sample-and-Hold (S/H) is connected to the input of the converter. The converter generates a 12-bit binary result via successive approximation and stores the conversion result into the ADC Result registers.

Additionally, the following features are provided within the ADC module:

  • Acquisition timer
  • Hardware Capacitive Voltage Divider (CVD) support:
    • Precharge timer
    • Adjustable Sample-and-Hold capacitor array
    • Guard ring digital output drive
  • Automatic repeat and sequencing:
    • Automated double sample conversion for CVD
    • Two sets of Result registers (Current Result and Previous Result)
    • Auto-conversion trigger
    • Internal re-trigger
  • Computation features:
    • Averaging and low-pass filter functions
    • Reference comparison
    • 2-level threshold comparison
    • Selectable interrupts
  • Automated channel scanning and context switching
    • Supports up to four unique configurations
    • Each configuration is saved as a context
    • Stop on threshold interrupt during a scan
    • Unique threshold interrupt for each configuration

The ADC voltage reference is software selectable to be either internally generated or externally supplied.

The ADC can generate an interrupt upon completion of a conversion and upon threshold comparison. These interrupts can be used to wake up the device from Sleep.

Figure 43-1. ADC Block Diagram