MiniSense 100 Analog PCB Evaluation Circuit for Vibration Sensor Low Power - Battery Powered LED for Trigger High Sensitivity Analog and Digital Signal Access Points The LDTC MiniSense 100 Analog PCB provides a simple way to evaluate the LDTC MiniSense 100. The unit consists of LDTC MiniSense 100, a low-power operation amplifier, comparator, and DC/DC converter, and passive components used in signal conditioning. The sensor and circuit are assembled on a double-sided PCB with test points, ON/OFF switch, and 0.100" plated through holes for easy user interface. The PCB has adjustable gain and demonstrates the basic capabilities of LDTC MiniSense 100 vibration sensor. FEATURES * Signal Conditioned Vibration Sensor * High Pass Filter @ 1.3Hz * Low Pass Filter @ 177Hz * On Board 3.3 Battery or User Power Supply * Both Analog and Digital Output specifications CHARACTERISTIC (T=25(C)) Lower Frequency Limit (-3dB Point) High Frequency Limit (-3dB Point) External Supply Voltage Supply Current SYMBOL MIN TYP MAX UNITS fL3dB - 1.3 - Hz fU3dB - 117 - Hz +V 0.9 3.3 5.5 VDC Isupply - 2.8 - mA pin descriptions PIN NUMBER 1 NAME VDD 2 3 A D 4 GND DESCRIPTION Connect to Power Supply Analog Signal output Digital Signal output Connect to GND **Note: when switch set to "OFF", PCB uses external power if applied to (+) & (-) input pins** APPLICATIONS * Wake-up Sensor * Drop Detection Sensor * Flow Sensor * Activity Sensor * Alarm Trigger MiniSense 100 Analog Rev 1 environmental characteristics CHARACTERISTICS T=25(C) SYMBOL MIN TYP MAX UNITS Operating Temperature Storage Temperature TOP TS -20 -40 - +85 +105 c c Relative Humidity RH 0 - 90 %R.H www.meas-spec.com 1 of 4 05/12/2009 MiniSense 100 Analog PCB electrical schematic MiniSense 100 Analog Rev 1 www.meas-spec.com 2 of 4 05/12/2009 MiniSense 100 Analog PCB electrical PCB reference electrical PCB description The impedance matching resistor, R5, in parallel with the 240pF sensor capacitance, establishes the high pass input filter at approximately 1.3Hz (f=1/2RC). After impedance buffering the LDTC signal is DC coupled to a gain stage through a 0.7Hz high pass filter formed by C10 and R10. The amplifier gain is set by R9, R6, and the R8 potentiometer in the OP-amp's feedback loop: Gain=1+ [R9/(R8+R6)] with a max gain of 20dB, min gain of 6dB. C6 in parallel with R9 in the feedback loop form a low pass filter with a corner frequency of 177Hz. After signal conditioning the analog voltage is buffered for output and also fed into a comparator. R15 & R4 set the threshold voltage. If the amplified signal exceeds the threshold voltage, the comparator output will be pulled low through a 4.7K resistor and the PNP transistor will turn on the LED. The reference voltage, VREF, is 1.65V, or half of the internal 3.3V rail. The on board 3.3V battery and external power are converted to a 5V supply using a DC-DC converter. frequency response Minisense 100 vibration sensor frequency response MiniSense 100 Analog Rev 1 www.meas-spec.com 3 of 4 05/12/2009 MiniSense 100 Analog PCB MiniSense 100 vibration sensor Analog PCB Acceleration Response The information in this sheet has been carefully reviewed and is believed to be accurate; however, no responsibility is assumed for inaccuracies. Furthermore, this information does not convey to the purchaser of such devices any license under the patent rights to the manufacturer. Measurement Specialties, Inc. reserves the right to make changes without further notice to any product herein. Measurement Specialties, Inc. makes no warranty, representation or guarantee regarding the suitability of its product for any particular purpose, nor does Measurement Specialties, Inc. assume any liability arising out of the application or use of any product or circuit and specifically disclaims any and all liability, including without limitation consequential or incidental damages. Typical parameters can and do vary in different applications. All operating parameters must be validated for each customer application by customer's technical experts. Measurement Specialties, Inc. does not convey any license under its patent rights nor the rights of others. ordering information Description Part Number MiniSense 100 Analog PCB 1007215 North America Europe Asia Measurement Specialties, Inc. 1000 Lucas Way Hampton, VA 23666 Sales and Customer Service Tel: +1-800-745-8008 or +1-757-766-1500 Fax: +1-757-766-4297 Technical Support Email: piezo@meas-spec.com MEAS Deutschland GmbH Hauert 13 44227 Dortmund Germany Sales and Customer Service Tel: +49 (0)231 9740 21 Technical Support Tel: +49 (0)6074 862822 Email: piezoeurope@meas-spec.com Measurement Specialties (China), Ltd. No. 26 Langshan Road ShenZhen High-Tech Park (North) Nanshan District ShenZhen, China 518107 Sales and Customer Service Tel: +86 755 3330 5088 Technical Support Email: piezo@meas-spec.com MiniSense 100 Analog Rev 1 www.meas-spec.com 4 of 4 05/12/2009