Datasheet

2
Signal Chain Design Guide
Signal Chain Overview
Typical Sensor Signal Chain Control Loop
Digital DomainAnalog Domain
Driver
(MOSFET)
Op Amp
DAC/PWM
Actuators
Motors, Valves,
Relays, Switches,
Speakers, Horns,
LEDs
ADC/
V-to-Freq
Amp
Sensors
Filter
Reference
Voltage
MUX
PIC
®
MCU
or dsPIC
®
DSC
Indicator
(LCD, LED)
Digital
Potentiometer
Typical sensor applications involve the monitoring of
sensor parameters and controlling of actuators. The
sensor signal chain, as shown below, consists of analog
and digital domains. Typical sensors output very low
amplitude analog signals. These weak analog signals
are amplified and filtered, and converted to digital values
using op amps, analog-to-digital or voltage-to-frequency
converters, and are processed at the MCU. The analog
sensor output typically needs proper signal conditioning
before it gets converted to a digital signal.
The MCU controls the actuators and maintains the
operation of the sensor signal conditioning circuits based
on the condition of the signal detection. In the digital
to analog feedback path, the digital-to-analog converter
(DAC), digital potentiometer and Pulse-Width-Modulator
(PWM) devices are most commonly used. The MOSFET
driver is commonly used for the interface between the
feedback circuit and actuators such as motors and valves.
Microchip offers a large portfolio of devices for signal
chain applications.