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EETE JAN 2014

ANALOG & MIXED SIGNAL DESIGN Android App automates Bluetooth and analogue audio testing for smartphones Audio Precision has released an Android app for testing smartphone audio quality. Serving as an interface between the Android device and one of Audio Precision’s APx audio analyzers, the app allows fast, automated profiling of new phones and tablets. It will be useful to network carriers, repair and refurbishment centres and other people who need to evaluate the audio performance of different models and manufacturers against a common standard. The Android app has four key features. It routes the audio through various analogue signal paths not normally allowed by stock Android OS (for example, making a closedloop test from analyzer to analogue line-in to device’s speaker and back to analyzer). It uses the device’s record feature, then transfer the resulting file to an APx audio analyzer over USB for analysis. The app also testes Bluetooth signal paths, including the playback of stimulus waveforms over Bluetooth Handsfree Profile (HFP) without initiating a phone call over the network. It automates the entire process with the APx desktop application to control the device over USB, allowing audio test sequences to run through all available signal paths with no user interaction required. The ability to route analogue audio through arbitrary inputs and outputs in loopback mode makes testing much faster than record and playback and enables real-time electroacoustic measurements. In addition, the default media player is bypassed, so there is no risk of user settings, EQ or resampling interfering with measurements. The ability to open a SCO and send signals over Bluetooth HFP directly from the phone takes the mobile network’s audio performance out of the equation. The stock Android OS does not allow files to be streamed over HFP. The AP app overrides this behaviour, allowing direct evaluation of the Bluetooth connection quality independent of the mobile network (the weakest link in the signal chain). The AP Smartphone App for Android supports sine, continuous sweep and multitone signals for music playback signal paths. For voice band, AP recommends using PESQ or POLQA MOS (mean opinion score) perceptual audio measurements, which are fully supported by the AP smartphone app and are incorporated in the accompanying APx project files and test waveforms. Audio Precision http://ap.com MEMS design software gets 64-bit upgrade Version 4.0 of the MEMS+ design software from Coventor is a full 64-bit implementation that adds the ability to export Verilog- A models. The 64-bit resolution allows more accurate modeling of MEMS sensors and actuators and the software is designed to operate in parallel with Matlab and Virtuoso design software from Mathworks and Cadence Design Systems Inc., respectively. The extension to 64-bits has been accompanied by an option to tune the software between accuracy and speed. Reduced-order models can be exported in Verilog-A format, for use by IC designers. These exported models simulate 100X faster than fully non-linear MEMS+ models and are compatible with all commercial analog/mixed-signal circuit simulators that support the industry-standard Verilog-A hardware description language. Within Coventor’s range of software MEMS+ 4.0 sits alongside CoventorWare and SEMulator3D. The combination provides support for the design of accelerometers, gyroscopes, microphones and many other types of MEMS. “We were able to create a Verilog-A ROM reduced order model of a complex gyro design in just a few minutes, allowing our ASIC team to work in parallel with the MEMS team on further design iterations,” said Tero Sillanpaa, ASIC design manager at Murata Electronics Oy, in a statement issued by Coventor. “Harmonic simulations in Cadence showed that the model maintained the expected modal frequencies and was stable. Moreover, transient startup simulations were very fast, on the order of 25 seconds CPU time for one seconds real time, before front-end electronic components including RC parasitics were added.” Coventor www.coventor.com Sensor signal-conditioning IC optimized for die stacking Analog and mixed-signal semiconductor supplier Zentrum Mikroelektronik Dresden AG (Dresden, Germany) is offering a 16-bit sensor signal conditioning IC with an integrated 18-bit DSP for linearization and calibration functions. The ZSSC3027 chip is intended for application in calibrated resistive sensor modules in high-resolution industrial, consumer and medical application, the company said. The 16-bit precision analog-todigital conversion includes features for battery-driven devices, including 930-microampere typical overall current consumption and a 20-nanoamp typical current in sleep mode. The voltage range is 1.7 to 3.6 volts. The ZSSC3027 can be used to provide digital compensation of signal offset, sensitivity, temperature and non-linearity, via an internal correction algorithm with coefficients stored on-chip in a multiple-time programmable non-volatile memory. Programming is via the ZSSC3027’s serial interface using PC-controlled calibration software provided in the chip’s evaluation kit. “The ZSSC3027 is designed for stacked die assembly together with a dedicated MEMS sensor element to provide the lowest form factor for MEMS-based sensors on the market. A typical application is barometric pressure sensors for mobile devices,” said Michael Georgi, Product Marketing Manager at ZMDI. The chip offers an accuracy of ±0.10 percent of full-scale output and operates over a temperature range of -40°C to 85°C. It is available as a die for wafer bonding. Die, samples and wafers are available from ZMDI. In component form and in 10,000 piece quantities the ZSSC3027 is priced at €0.70 per unit or US$0.95 per unit. Zentrum Mikroelektronik Dresden AG www.zmdi.com 30 Electronic Engineering Times Europe January 2014 www.electronics-eetimes.com


EETE JAN 2014
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