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.
An improved switched-emitter-follower for high-resolution GS/s-rate track-and-hold amplifiers
This paper presents an improved switched-emitter-follower for high-resolution GS/s-rate track-and-hold amplifier. A dummy switched-emitter-follower is introduced to compensate track-mode nonlinearity. And a clamping amplifier is utilized to reduce hold-mode feedthrough in high sample rate. The proposed switched-emitter-follower was chip verified in a 12bit 1GS/s THA based on 0.18pm SiGe BiCMOS process. Post-layout simulations show that the proposed THA achieves a spurious free dynamic range of 71 dB for 497 MHz input frequency at 1 GS/s rate. Operating from a 3.3V supply, the power dissipation of the proposed switched-emitter-follower is 156mW.
Self-assembly of pyridinium-tailored anthracene amphiphiles into supramolecular hydrogels.
The mixing of a polyacid cross-linker with a pyridinium-functionalized anthracene amphiphile afforded a supramolecular hydrogel through a self-assembly process that was primarily driven by π-stacking and electrostatic interactions.