PhD lecture: Andreu Sanuy Charles:”Wideband pulse amplifiers for the integrated cameras of the Cherenkov Telescope Array” [NOT TRANSLATED]

Thesis director is Dr. David Gascón Fora

This thesis is focused on novel design circuitry for the channel signal path of a Cherenkov Telescope camera. The amplification is divided into gain stages in order to achieve the requirements of the design. The first stage, presents an innovative low noise wideband pre-amplifier design while the second amplification stage proposes a novel gain circuitry design, being impossible with the classic schemes at the required technology. This second stage also derives and adapts the signal to the following parts of the read-out system of the Cherenkov Telescope camera.

An innovative design that achieves all the restrictions with very low power consumption fulfills the requirements for the first pre-amplification stage. The solution selected is based on a novel current mode circuit to create multiple gain paths at the very front end of the input stage of the readout electronics, simultaneously achieving high dynamic range, low noise, low input impedance, low voltage and low power performances.

The pre-amplification stage also comprises a closed loop transimpedance amplifier with a novel class AB output stage designed with a 0.35μm SiGe technology, allowing the design to drive a cable or a transmission line (typ. 50Ω load) while preserving high bandwidth with moderate power consumption.

This thesis presents an alternative method to implement fully differential wideband pulse amplifiers. The required gain can be reached, while preserving also the bandwidth. Linearity for fast pulses is at the level of solutions based on feedback OTA, limited by slew rate and other transient issues. The design exhibits a large degree of tuneability. An amplifier in a 0.35μm CMOS technology implements and validates the GBW product of 8 GHz. This design also incorporates a closed loop transimpedance amplifier with a novel class AB output stage based on the design of the first amplification stage, but designed in a 0.35μm CMOS technology which is more difficult to achieve. [NOT TRANSLATED]