Page 39

EETE JAN 2016

Analog design The fluid quickly evaporated, leaving a coating of graphene oxide flakes only a few tens of nanometers thick. The flakes are so thin that interaction with gas molecules changes their resistance in a measurable way, making them useful for sensing. According to Velásquez-García, the gas sensors obtained were as precise as a commercial product costing hundreds of dollars, while being faster and built for only a few cents. In their first implementation, the electrospray emitters used by Velásquez-García and Taylor had been built using conventional semiconductor processes. But in a second study published in the December issue of the Journal of Microelectromechanical Velásquez-García reports using an affordable, highquality to produce plastic electrospray emitters performance match those of the emitters gas sensors. Not only were the researchers able to make the electrospray cost-effective, 3-D printing allowed them to customize A completed chip with a wired graphene oxide gas sensor. The graphene oxide film is the greenish dot covering the electrode structure. Source: Anthony Taylor and Luis F Velásquez-García Ipdia makes thin silicon caps 3D silicon passive components provider Ipdia (Caen, France) has developed a range of low profile capacitors with electrostatic discharge (ESD) performance up whose size and that yielded the to 8kV. The capacitors are suitable for use in smart cards and RFID tags and in other applications where integration and antenna matching play key roles. The LPSC range targets antenna matching, RF filtering and decoupling of active die, in applications with height and volume constraints. The RFID 0402 capacitor range is 100-microns thick while providing stability over the specified voltage up to 150°C. The range covers values from 10pF up to 330pF, with the same thermal coefficient as standard RFID ICs and with proven assembly methods such as flip-chip and wirebonding. Furthermore, the capacitor range has been tuned to reach a series resonant frequency (SRF) higher than 1.2GHz, allowing antenna tuning from 13.56MHz up to 800/900MHz applications. Ipdia www.ipdia.com Systems, 3-D printer devices more the devices for particular applications, improving the micronozzles from one iteration to the next within days. Effectively, they were able to build new MEMS out of their custom MEMS fab desktop. Another big advantage is that the low process temperature allows sensor designers to deposit materials that would not be compatible with high-temperature semiconductor manufacturing, such as biological molecules with specific markers. The new fabrication technique could open up new application fields for MEMS while taking more IP to viable commercial products. “In some cases, MEMS manufacturers have to compromise between what they intended to make, based on the models, and what you can make based on the microfabrication techniques,” Velásquez-García explained. “Only a few devices that fit into the description of having large markets and not having subpar performance are the ones that have made it.” Optical micrograph of a fabricated conductometric graphene oxide gas sensor. The inset (top left corner) shows a close-up view of the active area of the sensor. Source: Anthony Taylor and Luis F Velásquez-García. Highest-performing audio op amp, claims TI Citing lowest distortion and noise, high linear output current, and low power, Texas Instruments says its latest audio amplifier pushes the boundaries for professional and portable audio. The OPA1622 is the newest addition to the company’s Burr-Brown Audio line and is the next generation of the widely adopted OPA1612. The OPA1622 delivers high output power of up to 150 mW and extremely low distortion of -135 dB at 10 mW, enabling the highest performance for professional audio equipment. The OPA1622’s small size, low power consumption and low distortion can deliver high-fidelity audio in portable devices such as headphone amplifiers, smartphones, tablets and USB audio digital-to-analogue converters (DACs).The OPA1622 op amp, TI adds; - Pushes the boundaries of audio quality: Headphone amplifier designers can take advantage of its low total harmonic distortion (THD) of -135 dB at 10-mW output power into a 32-Ω load – a claimed 12 times better than the nearest competitor. It also delivers maximum output power of up to 150 mW before clipping while maintaining the lowest THD and noise (THD+N), providing a clean signal path for professional audio applications. - Optimised for high-fidelity portable audio devices: Consumes quiescent current of 2.6 mA per channel and delivers high linear output current of 80 mA rms in a 3 x 3-mm dual flat no-lead (DFN) package. Increased power-supply rejection ratio (PSRR) of -97/-123 dB at 20 kHz enables low distortion from switching power supplies with no low-dropout regulator (LDO), saving board space without compromising audio performance. The OPA1622’s ground-referenced enable pin is directly controllable from the low-power processor’s GPIO pins without level-shifting circuits. Texas Instruments www.ti.com www.electronics-eetimes.com Electronic Engineering Times Europe January 2016 39


EETE JAN 2016
To see the actual publication please follow the link above