The SiFlexTM accelerometer has been designed and developed by Colibrys Inc. for “strong motion” seismic sensing applications. This MEMS capacitive product is the world best in class “digital geophone”, largely used for seismic and vibration sensing when extreme low noise measurement isrequired. Features such as wide dynamic range, excellent bandwidth, low distortion, high shock tolerance, and thermal stability make it ideal for applications such as earthquake and seismology measurements, homeland and border security or structure monitoring. Used as a tilt sensor, it also provides a very high resolution of measurement. This product exists in two versions (Table 1):-? The SF1500S / SF1500SN offers unmatched noise performance allied with robustness. This ± 3g MEMS
Fig. 1:SF2005 and SF1500 products sensor provides an extremely low noise of 300ngrms/√Hz and is ideal for strong motion measurements.
- The SF2005S/SF2005SN still offers a very low noise performance (800ngrms/√Hz) for a larger full scale (± 4g).
This makes it ideal for seismic sensing and structure monitoring where higher accelerations have to be measured.
Product description
The SiFlexTM products combine a MEMS capacitive accelerometer, based on a bulk micro-machined silicon element in a ceramic package attached through an interconnect board to a custom mixed-signal ASIC to enable closed-loop force-feedback operation of the accelerometer (Fig. 1).
The multi-chip module (MCM) assembly is mounted to a printed circuit board consisting of power conditioning electronics employing linear regulators, output amplifiers and other support electronics.
The SF1500 and SF2005 operate from a bipolar power supply voltage that can range from ± 6V to ± 15V with a typical current consumption of 12mA at ± 6V.
The linear full acceleration range varies from ± 3g for the SF1500 to from ± 4g for the SF2005 with a corresponding sensitivity of 1.2V/g and 0.8V/g respectively.
Both units can operate over a wide temperature range from -40°C to +125°C and can withstand a shock of up to 1500g without performance degradation. The frequency response over the full scale range is DC to >1000Hz.
