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miscelaneous 3D Plus promises universal space-grade colour CMOS camera module The CNES (French Space Agency) and 3D PLUS partner to develop a colour camera fully qualified for space applications, and due to embark on NASA’s Mars 2020. This development is a followup to a first R&D study that has been conducted between the two partners in 2015. It will be held over 14 months, and flight models are expected to be available beginning of 2017. The camera module will feature a 4Mpixel colour CMOS sensor, of high resolution-enough to provide good data while staying within a reasonable communication budget for power-constrained space applications. 3D Plus will receive the space qualified CMOS sensor from the CNES (who will perform thermal cycling from -55 to +125ºC, radiation exposure and vacuum tests) and integrate it with an FPGA, memory, power supply and custom circuitry, all previously space qualified, into its signature cubic form factor. The whole module will then go through another space qualification process, which the company admits represents the longest part of the development for such products. But it hopes to offer the final module off-the-shelf and competitively priced, designed to be universal enough to find its way into other space applications such as for example star trackers on board small satellites. For the Mars 2020 rover mission, the camera module will be installed in the SuperCam scientific instrument developed by Los Alamos Laboratory and IRAP (CNRS / Université Paul Sabatier, Toulouse, France). It will provide imaging, chemical composition analysis and mineralogy in rocks and regolith from a distance. The module will also be deployed on-board EYE-SAT, a nanosatellite developed by the CNES for earth and zodiacal light observation. 3D PLUS www.3d-plus.com Microstepping motor drive ICs with simple command interfacing Allegro’s A5976, A5977 and A5979 have been designed to operate bipolar stepper motors in full-, half-, quarter-, eight, (A5977) and sixteenth (A5976/79) step modes; the ICs are complete microstepping motor driver ICs with built-in translators. All have the output drive capability of 40V and ±2.8A and include a fixed off-time current regulator that has the ability to operate in slow, fast, or mixed-decay modes. This current-decay control scheme results in reduced audible motor noise, increased step accuracy, and reduced power dissipation. The translator is the key to the easy implementation of these devices. Simply inputting one pulse on the STEP input drives the motor one step or microstep (two logic inputs determine if it is a full-, half-, quarter-, eighth- or sixteenth-step resolution). There are no phase sequence tables, high-frequency control lines, or complex interfaces to program. The interface is a good fit for applications where a complex microprocessor is unavailable or overburdened. Internal synchronous rectification control circuitry is provided to improve power dissipation during PWM operation. Internal circuit protection includes OCP (overcurrent protection) thermal shutdown with hysteresis, undervoltage lockout (UVLO), and crossover-current protection. An opendrain FAULT output is included in the A5976 for improved diagnostic reporting. Special power-up sequencing is not required. All three devices are supplied in a thin, under 1.2-mm profile, 28-pin TSSOP with exposed thermal pad. Data sheets are at; A5976, A5977 and A5979 Allegro MicroSystems www.allegromicro.com Efficient car audio system PSU IC makes 2/3 power saving Addressing the car audio market for multifunction power supplies, Rohm has developed a system power supply IC for which it claims lowest-available power consumption. BD49101AEFS-M is based on a highefficiency DC/DC converter, achieving power consumption reduction of 65%, from 13.3W with Rohm’s conventional products to 4.66W. Less heat generation makes it possible to adopt a surface mount package without requiring an external heat sink, simplifying thermal designs considerably while contributing to greater space savings. Integrating all system power supplies required for car audio systems on a single chip – including for USB with a cable impedance function – contributes to a lighter design load. In DC/DC converters, because efficiency drops when the load current deceases (i.e. during standby), the BD49101AEFS-M integrates a low-current linear regulator dedicated for continuously powering the MCU. During standby operation the IC switches from the DC/DC converter to the linear regulator, reducing quiescent current that flows when the engine is idle to 100 μA (typ.). The device somes in a compact surface-mount package with small backside heatsink. This eliminates the need for thermal counter measures and results in 14x less volume compared with conventional products. When charging USB devices it is necessary to compensate for the drop in voltage caused by the cable wiring resistance. Rohm includes a built-in compensation function that maintains the cable end voltage, minimising charging time and ensuring compliance with USB standards. An output terminal is included for notifying the MCU of overcurrent conditions. Rohm Semiconductor www.rohm.com www.electronics-eetimes.com Electronic Engineering Times Europe February 2016 47


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