Improved GaAs HEMT Analog Switches for High-Precision and High-Speed Sampled Data ICs

This paper presents design considerations and an experimental comparison of GaAs HEMT analog switches for high-speed and high-precision sampled data ICs. In order to improve the switch dynamic performances, a dual dummy transistor compensation technique is used and related driver circuitry is developed. On-wafer measurements demonstrate that the improved switch provides a significant reduction of the transient errors, a reasonable dynamic range and a high isolation. The switch, with a 0.53 pF load capacitor, achieves a total harmonic distortion below ¿55 dB and ¿38 dB at 10 MHz and 1.0 GHz clock frequency, respectively.