Monday, December 13, 2010

Boost Supply and High-Voltage DAC Provide Tuning Signal for Antennas and Filters

Antenna arrays and filters are often tuned by varying the voltage on a barium strontium titanate capacitor. Voltages applied to this ferroelectric material cause small variations in the crystal structure, changing the dielectric constant and, thus, the capacitance. The capacitor is tuned by applying a voltage of up to 30 V. This article shows an easy way to generate a high-voltage tuning signal in a low-voltage system.

High-Side Current Sensing with Wide Dynamic Range: Three Solutions

Precision current sensing allows designers to measure motor torque, dc-to-dc converter efficiency, bias current in a power transistor, and other critical parameters in the presence of high common-mode voltages. This article describes three solutions—discrete, integrated, and application-optimized—that provide high-accuracy, high-resolution current sensing for a variety of applications.