Wednesday, July 06, 2011

Simple Ambient Light Sensor Circuit

Ambient light is increasingly considered as a source for harvesting energy to power heartbeat monitors, bathroom fixtures, remote weather sensors, and other low-power devices. At the heart of an energy-harvesting system is the ability to measure ambient light accurately. This design idea describes a simple, cost-effective circuit that provides a voltage proportional to the intensity of ambient light.

Differential Interfaces Improve Performance in RF Transceiver Designs

Traditional IF and RF transceivers use 50-Ω single-ended interfaces, with interconnected circuits all seeing matching input and output impedances. In modern transceiver designs, differential interfaces provide better performance, but implementing them requires designers to confront impedance matching, common-mode voltage matching, and difficult gain calculations. This article offers some assistance.