A gigasample/second 5-b ADC with on-chip track and hold based on an industrial 1 mu m GaAs MESFET E/D process

To enhance the dynamic accuracy of high-speed A/D conversion, a 5-b flash converter with on-chip track and hold circuitry (T&H) was developed. The design is based on TriQuint's commercial 1 mu m GaAs E/D MESFET process. Dynamic characterization was performed up to 1 gigasample/second (GS/s). An accuracy of 4.4 effective bits even at 1 GS/s with full Nyquist input was achieved. A comparison showing the accuracy with T&H in operation and in tracking-only mode is given. The outstanding performance is due to a carefully designed and the use of differential source-coupled FET logic (SCFL) in the converter.<
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