Andreu Sanuy

Wideband (500 MHz) 16 bit dynamic range current mode PreAmplifier for the CTA cameras (PACTA)

A wideband current mode preamplifier with 16 bits dynamic range (DR) is presented. It has been designed for the cameras of the Cherenkov Telescope Array (CTA). A novel current division scheme at the very front end part of the circuit splits the input current into two scaled currents which are connected to independent current mirrors. The mirror of the high gain path comprises a saturation control circuit for accurate current division. Measurement results of an ASIC designed in Austriamicrosystems 0.35 μm SiGe technology are presented: 500 MHz BW, 16 bits DR, 10 pA/sqrt(Hz) input referred noise current and relative linearity error below 3%.

An optical interface for inter-robot communication in a swarm of microrobots

It is described the optical communication interface for short-range communications of robots in a microrobotic swarm between thousands of units. The robots, of 27 mm3-size, will be deployed in an arena of A4 sheet size with controlled illumination conditions. The communication between robots is done via IR light. The interface can handle variations of IR background light from point to point in the arena, deals with robot different orientation and distance, i.e., the amplitude of the signal to be detected, and with interferences of other robots. The interface has been designed to manage the low energy available in the robot.

An ultra low power IC for an autonomous mm 3 -sized microrobot

This paper is focused on the main issues of designing a SoC for a completely autonomous mm3-sized microrobot. It is described how all the electronics are included in a unique chip, the special requirements in the assembly process and how the hard constraints in power consumption are managed. Power in the robot is delivered by solar cells mounted on top and two supercapacitors which act as batteries. The maximum available energy for the SoC is 400 muW for driving the robot actuators and 1 mW for data processing. The special architecture of the SoC and power awareness are required to manage the very low available power.

A Wake-Up Circuit With Temperature Compensated Clock In 1.2V-0.13 μm CMOS Technology

This paper reports on the design and implementation of a low-voltage, low-power Wake-Up circuit consisting on a Power-on-Reset module and a clock generator. No external components are used neither for the Power-on- Reset nor for the clock generation. The clock generator module is temperature compensated by applying a current limiting technique. The Wake-Up circuit has been fabricated in a 130 nm ultra-low power technology of STMicroelectronics in an area of 40 μm times 40 μm.

Wideband (500 MHz) 16 bit dynamic range current mode input stage for photodetector readout

A low noise wideband current mode circuit with 16 bit dynamic range (DR) is presented. It has been designed as input stage of a transimpedance preamplifier for the readout of the cameras of the Cherenkov Telescope Array (CTA) project. A novel current division scheme at the very front end part of circuit is used to split the input current in two or more scaled output currents which are connected to independent current mirrors. The mirror of the high gain path comprises a dedicated saturation control circuit needed to assure an accurate current division. Two ASIC prototypes have been designed in AMS SiGe BiCMOS 0.35um technology. Measurement results are presented: BW of 500 MHz, DR of 16 bits, input referred ENC below 4000 electrons and relative linearity error below 2%. The current mode circuit can be operated at 3.3 V and lower, with low power consumption (< 10 mW).

An optically programmable SoC for an autonomous mm 3 -sized microrobot

A microrobot is a robot under a few cubic millimeters in size. Miniaturizing its components, power source, sensors and actuators, has proven challenging. As a consequence, few autonomous microrobots have been reported until recently [1–3]. These are simple mobile platforms, without sensors on board. Their electronics are basically focused on motion. I-SWARM is the first autonomous microrobot, 23mm3 and 70mg, designed to move, sense, take decisions, communicate and work in cooperation with other I-SWARM microrobots [4]. The area and weight of a microrobot are critical and limits the use of off-the-shelf components. So, it is required to integrate in a unique chip all the electronics, including the clock source, the POR and the voltage regulators.

MUSIC: An 8 channel readout ASIC for SiPM arrays

This paper presents an 8 channel ASIC for SiPM anode readout based on a novel low input impedance current conveyor (under patent1). This Multiple Use SiPM Integrated Circuit (MUSIC) has been designed to serve several purposes, including, for instance, the readout of SiPM arrays for some of the Cherenkov Telescope Array (CTA) cameras. The current division scheme at the very front end part of the circuit splits the input current into differently scaled copies which are connected to independent current mirrors. The circuit contains a tunable pole zero cancellation of the SiPM recovery time constant to deal with sensors from different manufacturers. Decay times up to 100 ns are supported covering most of the available SiPM devices in the market. MUSIC offers three main features: (1) differential output of the sum of the individual input channels; (2) 8 individual single ended analog outputs and; (3) 8 individual binary outputs. The digital outputs encode the amount of collected charge in the duration of the digital signal using a time over threshold technique. For each individual channel, the user must select the analog or digital output. Each functionality, the signal sum and the 8 A/D outputs, include a selectable dual-gain configuration. Moreover, the signal sum implements dual-gain output providing a 15 bit dynamic range. Full die simulation results of the MUSIC designed using AMS 0.35 µm SiGe technology are presented: total die size of 9 mm2, 500 MHz bandwidth for channel sum and 150 MHz bandwidth for A/D channels, low input impedance (≈32 Ω), single photon output pulse width at half maximum (FWHM) between 5 and 10 ns and with a power consumption of ≈ 30 mW/ch plus ≈ 200 mW for the 8 ch sum. Encapsulated prototype samples of the MUSIC are expected by March 2016.

Enabling swarm behavior in mm 3 -sized robots with specific designed integrated electronics

This paper presents a system on chip (SoC) designed specifically to control a mm3-sized microrobot called I-SWARM. The robot is intended to be part of a colony of 1000 members for studying swarm behavior in real time with real robots. The SoC offers a well-suited hardware platform to run multi-agent systems software. The SoC enables control of movement, communications and sensing. It is a platform where run multi-agent system software. With these capabilities, the robot is able for example to avoiding collisions, perform cooperative tasks, share information and, of course, solve different swarm scenarios and more complex tasks. The SoC has been fabricated with a 0.13 mum ultra low power CMOS process of STMicroelectronics and consumes less than 1.5 mW.

A SoC for studying multi-agent software/algorithms on a real swarm of mm3-sized microrobots

This paper presents a System On Chip (SoC) designed specifically to control a mm3- sized microrobot called I-SWARM. The robot is intended to be part of a colony of 1000 I-SWARM robots for studying swarm behavior in real time and in a real swarm. The SoC offers a well-suited hardware platform to run multi-agent systems software. It is composed of an 8051 microcontroller with 2 kB of data memory and 8 kB of program memory. The processor is provided with specific hardware modules for controlling the locomotion unit, the communications and the vibrating contact sensor of the robot. These modules perform basic tasks as movements or communications so the 8051 can focus on processing data and taking decisions. With these capabilities, the robot is able to avoiding collisions with other members of the swarm, performing cooperative tasks, sharing information and executing specialized tasks. The SoC has been fabricated with a 0.13 &mgr;m ultra low power CMOS process of STMicroelectronics and consumes less than 1 mW.

Performance of the FlexToT v2 ASIC on the readout of different detector designs for PET

A new version of the FlexToT application-specific integrated circuit (ASIC) has been designed and fabricated with an extended dynamic range and improved channel uniformity suitable for readout of different detector block designs in time of flight (TOF) positron emission tomography (PET) applications. The performance of the FlexToT v2 ASIC has been evaluated using segmented, monolithic and phoswich scintillator elements and matrices coupled to silicon photmultiplier (SiPM) arrays. The enhanced dynamic range of FlexToT v2 compared to its previous version allows the correct identification of individual crystals in scintillator matrices, both single layer and phoswich. Operation with monolithic scintillators was also demonstrated, with energy resolutions of 18% (FWHM) at 511 keV and reconstructed PET images of point sources yielding spatial resolutions on the order of 2 mm (FWHM). The results show that the FlexToT v2 ASIC is a flexible solution for the front-end readout of different designs of SiPM-based scintillator detectors in TOF-PET applications.