A 2.5-GS/s 62dB THD SiGe Track-and-Hold Amplifier with feedthrough cancellation technique
In this paper a Track-and-Hold Amplifier (THA), designed in a low cost 0.35μm SiGe 60GHz technology is presented. Thanks to the joint action of a novel input buffer and a suppression feedthrough architecture, it is able to guarantee 62dB Total Harmonic Distortion(THD) up to a frequency of 2.2GHz with 0.9Vp-p differential input at a sampling rate (Fs) of 2.5GS/s. The THA core draws about 145mA from 3.5V supply.
Design and Characterization of a 3-bit 24-GS/s Flash ADC in 28-nm Low-Power Digital CMOS
This paper presents the design and characterization of a 24-GS/s 3-bit single-core flash analog-to-digital converter (ADC) in 28-nm low-power digital CMOS. It shows the design study of the track-and-hold circuit and subsequent buffer stage and provides equations for bandwidth calculations without extensive circuit simulations. These results are used to target leading-edge speed performance for a single ADC core. The ADC is capable of achieving its full sampling rate without time interleaving, which makes it the fastest single-core ADC in CMOS reported to date to the best of our knowledge. With a power consumption of 0.4 W and an effective number of bits of 2.2 at 24 GS/s, the ADC achieves a figure of merit of 3.6 pJ per conversion step while occupying an active area of 0.12 mm2. Due to its high sampling frequency this ADC can enable ultra-high-speed ADC systems when combined with moderate time interleaving.
Finite Difference Modeling on the Temperature Field of Substrate in Friction Surfacing
Friction surfacing is an advanced process of great potential, especially in the field of repair and reclamation of worn and damaged components. As a kind of thermal processing technology, the temperature profile and changes of the substrate in friction surfacing are important factors to get coatings of high quality. In this paper, the temperature field of the substrate during the process is simulated by finite difference method. The results are consistent with experiments, reappearing the temperature change of the substrate during friction surfacing, allowing further study on figuration and quality of coatings.