AN865
Title:
Sensing Light with a Programmable Gain Amplifier
Description:
Photo sensors bridge the gap between light and electronics. Microchip’s Programmable Gain Amplifiers (PGAs) are not well suited for precision applications (such as CT scanners), but they can be effectively used in position photo sensing applications minus the headaches of amplifier stability. When the two, six or eightchannel PGA is used in this system, the other channels can be used for other sensors or an array of photo sensors without an increase in signal conditioning hardware or PICmicro® microcontroller I/O pin consumption. The multiplexer and high-speed conversion response of the PGA / Analog-to-Digital (A/D) conversion allows the photo sensor input signal to be sampled and quickly converted to the digital domain. Switching from channel-to-channel is then easier with the Serial Peripheral Interface (SPI™) from the PICmicro microcontroller to the PGA.
Keywords:
PGA. Picmicro, spi
