An Auto-Zero-Stabilized Voltage Buffer With a Quiet Chopping Scheme and Constant Sub-pA Input Current

This article describes an auto-zero stabilized voltage buffer that achieves low offset and low noise with sub-pA input current. A high gain stabilization loop is used to periodically cancel the buffer’s offset. The loop itself is periodically disconnected from the buffer and auto-zeroed, during which its bandwidth is reduced to reduce the...

A Fill-In Technique for Robust IMD Suppression in Chopper Amplifiers

In chopper amplifiers, the interaction between the input signal and the chopper clock can give rise to intermodulation distortion (IMD). This chopper-induced IMD is mainly due to amplifier delay, which causes large pulses at the output of the amplifier's output chopper. This article proposes the use of a so-called fill-in technique to eliminate...

A Sampled Voltage Reference

A sampled voltage reference aims to achieve both low-power and low-noise by storing the output of a voltage reference on a capacitor for a long time. This allows the reference to be switched off during the hold period, which leads to lower average power. At the same time, all the voltage reference's noise is pushed down into a bandwidth...

Design of Front-End Receiver Electronics for 3D Trans-Esophageal Echocardiography

The motivation behind this thesis is that cardio-vascular diseases claim the highest number of lives each year globally. In order to enhance the accuracy in diagnosis, construction of 3D images of the heart is required. From these images, precise information can be obtained regarding the 3D anatomy of the heart and its functioning. Trans...

DLL Based Single Slope ADC For CMOS Image Sensor Column Readout

This thesis presents a Delay Locked Loop(DLL) based Single Slope ADC. Compared to the convertional Single Slope ADC, the readout speed is increased by 16 times. A DLL is designed with a start-controlled Phase Frequency Detector (PFD), a differential ended Charge Pump (CP) and fully differential Delay Cells (DC). The multi-stage comparator with...

A Current-Feedback Instrumentation Amplifier With 5 µV Offset for Bidirectional High-Side Current-Sensing