Maxim Integrated MAXQ Family Users Guide: MAXQ2010 Supplement - Manual (Page 83)

MAXQ Family User’s Guide:
MAXQ2010 Supplement
19-1
SECTION 19: ANALOG-TO-DIGITAL CONVERTER (SPECIFIC TO
MAXQ2010)
The MAXQ2010 provides a 12-bit, successive approximation analog-to-digital converter (ADC) with an integrated
analog multiplexer. The ADC can perform either single-ended conversions from one of eight channels or differential
conversions from one of four channel pairs. The voltage reference used for each conversion can be selected from an
internal precision bandgap reference, an external reference, or the AVDD analog power supply.
19.1 Analog-to-Digital Converter Features
• 12-bit single-ended conversion with up to eight analog channel inputs
• 12-bit differential conversion with up to four analog channel pair inputs (each differential pair takes the place of two
single-ended channel inputs)
• Autoscan feature performs up to eight conversions in sequence automatically without CPU intervention
• Conversion sequence can be performed once (single conversion mode) or repeatedly (continuous conversion mode)
• Up to 16 sample words can be stored in a dedicated data buffer until the processor is ready to retrieve them
• Selectable clock divider runs the ADC from a divide by 1, divide by 2, divide by 4, or divide by 8 of the system clock
• Sample acquisition time can optionally be extended on a per-conversion basis
• Data results can be left-aligned or right-aligned on a per-conversion basis
• Converter reference is switchable among AVDD, internal reference, and external reference
• Optional power management mode shuts the ADC off between conversions to save power
• Configurable data available interrupt signals the CPU following each conversion, each sequence, or after every 12
or 16 samples
Figure 19-1. ADC Block Diagram
CPU
INTERFACE ADC
SEQUENCER
12-BIT
SAR ADC
ADCN
ADST
ADADDR
ADDATA
ADCFG[0]
ADCFG[1]
ADCFG[2]
ADCFG[3]
ADCFG[4]
ADCFG[5]
ADCFG[6]
ADCFG[7]
ADBUF[0] ADBUF[8]
ADBUF[1] ADBUF[9]
ADBUF[2] ADBUF[10]
ADBUF[3] ADBUF[11]
ADBUF[4] ADBUF[12]
ADBUF[5] ADBUF[13]
ADBUF[6] ADBUF[14]
ADBUF[7] ADBUF[15]
ANALOG
MULTIPLEXER
AN3
AN4
AN5
AN0
AN1
AN2
AN6
AN7