Innovative Compensation Techniques Help To Improve Our Performance

“We ensure performance stability and repeatability at high temperatures through the design of the signal-processing circuitry in the ASIC,” explains Wayne Meyer, marketing and applications manager for the Analog Devices MEMS and Sensor Technologies Division.

These days, ADI company has released a new product called ADXL206. This semiconductor device is a dual-axis iMEMS accelerometer which can tackle tasks with its signal-conditioned analog outputs. It performs measurements while drilling, at several hours in each well during its creation, and continuously keeps on running. The packaged product integrates the sensing element and the signal-conditioning circuitry on a single monolithic chip.

The accelerometer, which is well suited for geological drilling tools and other extreme high-temperature industrial fields with its excellent stability, measures acceleration over a full-scale range of ±5 g with a resolution of 1 mg. It also measures both dynamic acceleration such as tilt and static acceleration such as gravity, all while operating from –40°C to 175°C. Shock survival is rated at 3500 g. All of this comes in a RoHS-compliant (Restrictions on Hazardous Substances) eight-lead side-brazed ceramic dual-inline package that’s just 13 by 8 by 2 mm.

Although the upper operating temperature of 175°C is guaranteed for 1000 hours, the sensor can recover 100% of the measured data beyond that limit, at diminished performance, thanks to innovative compensation techniques. This is ensured through the design of the signal-processing ASIC whose size is minimized, compared to other competitive approaches that usually employ large and bulky circuitry that constrains maneuverability in down-hole operations.

“As designers put together smart drilling systems that go miles and miles under the earth’s surface, they are challenged to balance power and space requirements against the need for more information,” says Pam Aparo, segment marketing manager for instrumentation at Analog Devices. “The ADXL206 is not only extremely compact, but it also lower power consumption by an order of magnitude from over 10 mA to under 0.5 mA per axis.”

The accelerometer’s bandwidth is user-selectable with capacitors at the chip’s X and Y outputs. A bandwidth of 0.5 Hz to 2.5 kHz is available to suit the application.

“Instead of using additional temperature-compensation circuitry, innovative design techniques have been used to ensure that high performance is built in. As a result, there is essentially no quantization error or non-monotonic behavior, and temperature hysteresis is very low, typically 2 mg over the entire operating-temperature range of –40°C to 175°C. This product is once again demonstrates the ADI’s leadership in the field of the high-performance MEMS inertial sensors.” Added Wayne Meyer.

Key Features of DXL206 iMEMS accelerometer:

1. –40 °C to +175 °C temperature range

2. 1 mg resolution at 60 Hz

3. Low power: 700 µA at VS = 5 V (typical)

4. High zero g bias repeatability

5. High sensitivity accuracy

6. 3500 g shock survival

Article source: http://www.hqew.net/article/showdetails-article-217.html