Datasheet

22
Signal Chain Design Guide
Related Support Material
The following literature is available on the Microchip web
site: www.microchip.com/appnotes. There are additional
application notes that may be useful.
Application Related Documentation
Sensor Conditioning Circuits Overview
AN866: Designing Operational Amplifier Oscillator
Circuits For Sensor Applications
Operational amplifier (op amp) oscillators can be used
to accurately measure resistive and capacitive sensors.
Oscillator design can be simplified by using the procedure
discussed in this application note. The derivation of
the design equations provides a method to select the
passive components and determine the influence of each
component on the frequency of oscillation. The procedure
will be demonstrated by analyzing two state-variable RC
op-amp oscillator circuits.
AN990: Analog Sensor Conditioning Circuits,
An Overview
Analog sensors produce a change in an electrical property
to indicate a change in its environment. This change in
electrical property needs to be conditioned by an analog
circuit before conversion to digital. Further processing
occurs in the digital domain but is not addressed in this
application note.
Delta-Sigma ADCs
AN1156: Battery Fuel Measurement Using Delta-
Sigma ADC Devices
This application note reviews the battery fuel measurement
using the MCU and ADC devices. Developing battery fuel
measurement in this manner provides flexible solutions
and enables economic management.
DS21841: Analog-to-Digital Converter Design Guide
SAR ADCs
AN246: Driving the Analog Inputs of a SAR
A/D Converter
This application note delves into the issues surrounding
the SAR converter’s input and conversion nuances to
insure that the converter is handled properly from the
beginning of the design phase.
AN688: Layout Tips for 12-Bit A/D Converter
Application
This application note provides basic 12-bit layout
guidelines, ending with a review of issues to be aware of.
Examples of good layout and bad layout implementations
are presented throughout.
AN693: Understanding A/D Converter
Performance Specifications
This application note describes the specifications used to
quantify the performance of A/D converters and give the
reader a better understanding of the significance of those
specifications in an application.
AN842: Differential ADC Biasing Techniques,
Tips and Tricks
True differential converters can offer many advantages
over single-ended input A/D Converters (ADC). In addition
to their common mode rejection ability, these converters
can also be used to overcome many DC biasing limitations
of common signal conditioning circuits.
Utility Metering
DS01008: Utility Metering Solutions
Digital Potentiometers
AN691: Optimizing the Digital Potentiometer in
Precision Circuits
In this application note, circuit ideas are presented that
use the necessary design techniques to mitigate errors,
consequently optimizing the performance of the digital
potentiometer.
AN692: Using a Digital Potentiometer to Optimize a
Precision Single Supply Photo Detect
This application note shows how the adjustability of the
digital potentiometer can be used to an advantage in
photosensing circuits.
AN1080: Understanding Digital Potentiometer
Resistance Variations
This application note discusses how process, voltage and
temperature effect the resistor network’s characteristics,
specifications and techniques to improve system
performance.
AN1316A: Using Digital Potentiometers for
Programmable Amplifier Gain
This application note discusses implementations of
programmable gain circuits using an op amp and a digital
potentiometer. This discussion includes implementation
details for the digital potentiometer’s resistor network.