Technology Scaling Impact on Embedded ADC Design for Telecom Receivers

This paper is concerned with the impact of technology scaling on the choice of A/D converters in telecom receivers. It is shown that the trend of diminishing feature size, together with better matching of passive components, allows the use of A/D topologies traditionally confined to low-frequency, medium-resolution applications. The design of a 10 bit 20 MS/s ADC using the successive approximation algorithm is presented in order to validate the presented concepts. By using a deep-submicron technology, the speed of the chosen architecture is pushed to meet the desired output rate

Efficient Saturation Control for Fully Differential Integrator in Continuous-Time Sigma-Delta Modulators

This paper presents an alternative approach to saturation control in an integrator, that occurs in Sigma-Delta modulators (SDMs). This solution simplifies the design process with a 1.2- V power supply and consumes significantly less power than conventional saturation control methods. Additionally, this solution provides a good phase margin, that guarantees the stability, without requiring additional compensation techniques, and it has the added benefit of reducing the gain of the integrator as the system enters saturation, while also maintaining integrator inputs fixed at the proper common-mode voltage. This innovative approach offers a promising solution for efficient and stable saturation control in SDM integrators, preventing distortion in the output signal, with potential applications in a wide range of electronic systems, such as audio systems. The circuit has been designed in a 90-nm CMOS technology

PixFEL: development of an X-ray diffraction imager for future FEL applications

A readout chip for diffraction imaging applications at new generation X-ray FELs (Free Electron Lasers) has been designed in a 65 nm CMOS technology. It consists of a 32 × 32 matrix, with square pixels and a pixel pitch of 110 µm. Each cell includes a low-noise charge sensitive amplifier (CSA) with dynamic signal compression, covering an input dynamic range from 1 to 104 photons and featuring single photon resolution at small signals at energies from 1 to 10 keV. The CSA output is processed by a time-variant shaper performing gated integration and correlated double sampling. Each pixel includes also a small area, low power 10-bit time-interleaved Successive Approximation Register (SAR) ADC for in-pixel digitization of the amplitude measurement. The channel can be operated at rates up to 4.5 MHz, to be compliant with the rates foreseen for future X-ray FEL machines. The ASIC has been designed in order to be bump bonded to a slim/active edge pixel sensor, in order to build the first demonstrator for the PixFEL (advanced X-ray PIXel cameras at FELs) imager

PixDD: a multi-pixel silicon drift detector for high-throughput spectral-timing studies

The Pixelated silicon Drift Detector (PixDD) is a two-dimensional multi-pixel X-ray sensor based on the technology of Silicon Drift Detectors, designed to solve the dead time and pile-up issues of photon-integrating imaging detectors. Read out by a two-dimensional self-triggering Application-Specific Integrated Circuit named RIGEL, to which the sensor is bump-bonded, it operates in the 0:5 — 15 keV energy range and is designed to achieve single-photon sensitivity and good spectroscopic capabilities even at room temperature or with mild cooling (< 150 eV resolution at 6 keV at 0 °C). The paper reports on the design and performance tests of the 128-pixel prototype of the fully integrated system

The large area detector onboard the eXTP mission

The Large Area Detector (LAD) is the high-throughput, spectral-timing instrument onboard the eXTP mission, a flagship mission of the Chinese Academy of Sciences and the China National Space Administration, with a large European participation coordinated by Italy and Spain. The eXTP mission is currently performing its phase B study, with a target launch at the end-2027. The eXTP scientific payload includes four instruments (SFA, PFA, LAD and WFM) offering unprecedented simultaneous wide-band X-ray timing and polarimetry sensitivity. The LAD instrument is based on the design originally proposed for the LOFT mission. It envisages a deployed 3.2 m2 effective area in the 2-30 keV energy range, achieved through the technology of the large-area Silicon Drift Detectors - offering a spectral resolution of up to 200 eV FWHM at 6 keV - and of capillary plate collimators - limiting the field of view to about 1 degree. In this paper we will provide an overview of the LAD instrument design, its current status of development and anticipated performance

The Evolution of Integrated Interfaces for MEMS Microphones

Over the last decade, MEMS microphones have become the leading solution for implementing the audio module in most portable devices. One of the main drivers for the success of the MEMS microphone has been the continuous improvement of the corresponding integrated interface circuit performance in terms of both dynamic range and power consumption, which enabled the introduction in mobile devices of additional functionalities, such as Hi-Fi audio recording or voice commands. As a result, MEMS microphone interface circuits evolved from just simple amplification stages to complex mixed-signal circuits, including A/D converters, with ever improving performance. This paper provides an overview of such evolution based on actual design examples, focusing, finally, on the latest cutting-edge solutions