A Single Supply Wide Bandwidth 4 : 1 Video Multiplexer in an 8 GHz

A high performance monolithic 4:1 analog multiplexer implemented in an 8 GHz dielectrically isolated complementary bipolar process was designed and simulated. It is useful in many general purpose high-speed applications such as driving an 150 Q cable or an analog to digital (A/D) converter. This switched transconductance amplifier 4:1 video multiplexer has a current mode decoder, a voltage feedback amplifier and four PNP-differential-pair input stages. It has a -3 dB small signal bandwidth of 148 MHz and a slew rate of greater than 170 V/us. It has a differential gain and a differential phase error of 0.03% and 0.030. With -113 dB of all-hostile crosstalk and -91 dB of off isolation at 10 MHz, this multiplexer is compatible with a 10 bits A/D converter. It has a channel switching time to 0.1% of 15 ns and consumes less than 6.4 mA on a 5 V single supply voltage. The output voltage swing of this multiplexer extends to within 50 mV of each rail, providing a wide output dynamic range. It offers a high-speed disable feature allowing the output to be put into a high impedance state for multi-stages so that the off channel does not load the output bus. This shutdown feature also reduces the supply current to less than 2.6 mA. Thesis Supervisor: James K. Roberge Title: Professor of Electrical Engineering