A TTL COMPATIBLE RF SWITCH TOPOLOGY FOR GaAs MMIC APPLICATIONS
Original Publication Date: 1992-Dec-01
Included in the Prior Art Database: 2002-Jan-22
Some of the earliest successful C&As MMIC cir- cuits include RF switches, which form one of the basic building blocks used in RF and microwave systems. However, GaAs switch control inputs range from 0 to -3 volts. TTL control logic ranges from 0 to +5 volts. Thus, a separate driver circuit has been required to inter- face between the switch and the TfL logic circuits. This separate driver circuit consumes power, increases con- trol propagation times, adds substantial circuitry which affects reliability, increases semiconductor area, and atfects product cost. This article describes a method of realiz- ing a TTL compatible GaAs MMIC RF switch, completely eliminating the requirements for a separate driver.