Advance improves DC-to-DC converters

NEGATIVE voltages have long been the curse of GaAs metal-semiconductor field-effect transistors (MESFETs), Since the depletion-mode transistors that are commonly used in GaAs monolithic microwave integrated circuits (MMICs) require negative-voltage supplies, circuit designers have been forced to develop elaborate biasing schemes with multiple external components. In what might be considered a major advance in DC-to-DC converter technology, however, the engineers at GaAs-specialist ANADIGICS, Inc. (Warren, NJ) have announced a switching converter that operates not at audio frequencies but at microwave frequencies.