Models 900CT & 900BT Single Channel – Tunable Active Filter Instrument Certified Description Frequency Devices’ Models 900CT & 900BT instruments are single channel; 8-pole low-pass or high-pass, front panel tunable filter instruments. The controls allow the user to select a corner frequency between 0.1 Hz and 49.9 kHz with a resolution of 1:499 for each of the four selectable ranges. The instrument exhibits an input impedance of 1 MΩ shunted by 47pF to a single ended signal source. When configured in the differential mode, the instrument has a common mode rejection ratio (CMRR), which exceeds 60dB; in this mode the instrument presents an input impedance of 2 MΩ’s shunted by 47pF to a double-ended single source. Front panel gain control also enables the operator to select a gain factor of 0, 10, or 20dB. Models 900CT 900BT Standard operational features include: 1) Adjustable Frequency Control 2) Differential Input Amplifiers 3) Adjustable Gain Control 4) Off-set Adjustment 5) Bypass Control 6) BNC Connectors for Signal I/O The optional battery powered 900BT is particularly well suited to applications requiring isolation from an electrically noisy primary power source. Compact size and manual rotary switch front panel controls make 900 instruments a popular, cost effective, easy-to-use solution for signal conditioning applications in the following areas: Anti-aliasing Filters Biomedical/Biotechnology Applications Data Recording/Playback Data Smoothing EKG/EEG Signal Filtering FDM/PCM Signal Filtering Medical Research Industrial Process Control Seismic Analysis Vibration Analysis Standard AC Powered AC Powered, with battery option Available Low-Pass Filters: Part# #Poles 900L8B 8 900L8L 8 900L8E 8, 6 zero 900L8EY 8, 6 zero 900L8D80 8, 6 zero 900L8D100 8, 6 zero Filter Type Page Butterworth 6 Bessel 6 Elliptic, 1.77 6 Elliptic, 2.00 6 Constant Delay 7 Constant Delay 7 Available High-Pass Filters: Part# #Poles 900H8B 8 900H8E 8, 6 zero 900H8EY 8, 6 zero Filter Type Butterworth Elliptic, 1.77 Elliptic, 2.00 Block Diagram Front & Rear panel descriptions General Specifications: Ordering Information Page 8 8 8 2 4&5 9 10 1 1784 Chessie Lane, Ottawa, Illinois 61350 • Tel: 800/252-7074, 815/434-7800 • FAX: 815/434-8176 e-mail: [email protected] • Web Address: http://www.freqdev.com Models 900CT & 900BT Single Channel – Model 900 Series Instrument Block Diagram Certified BLOCK DIAGRAM GAIN (dB) INPUT 10dB 0dB 20dB A A-B + OUT 8-POLE TUNABLE FILTER DIFF AMP A OUTPUT AMP BYPASS OFFSET NULLED B CORNER FREQUENCY TUNING OFFSET 1 0 2 3 TYPICAL FRONT PANEL BNC CONNECTOR TYPICAL ADJUSTMENT FUNCTION CORNER FREQUENCY HZ 5 5 4 4 6 4 MULTIPLIER 10 1 100 6 3 7 3 7 0.1 2 8 2 8 1 0 9 1 0 FRONT PANEL 9 2 1784 Chessie Lane, Ottawa, Illinois 61350 • Tel: 800/252-7074, 815/434-7800 • FAX: 815/434-8176 e-mail: [email protected] • Web Address: http://www.freqdev.com Models 900CT & 900BT Single Channel – Model 900 Series Initial Setup Procedure Certified Initial Setup Select desired operating voltage 115 Vac or 230 Vac. See note "Q" on Page 5. Set the OFFSET control for a zero-volt reading on the scope or DVM. Set the POWER ON/OFF Switch to ON. A continuously lit POWER lamp indicates proper internal DC voltages, an essential requirement for battery-powered models. Allow the instrument a three-minute warm-up period to achieve thermal equilibrium. Subsequent changes of CORNER FREQUENCY and GAIN control settings will introduce a small dc output offset, which should be zeroed for critical applications. Leaving all other controls unchanged, set the Input Switch to (A-B) and apply a 5Vdc signal simultaneously to input BNCs (A) and (B). The voltage measured at the OUT BNC should be 5 - 5 = 0 Vdc. This completes preliminary test and adjustment. To perform initial adjustment and/or operational testing, set the remaining front panel controls as follows: a) The three base CORNER FREQUENCY switches and the MULTIPLIER to the desired corner frequency… Corner Frequency Selection To select a corner frequency, simply set the three CORNER FREQUENCY switches and the MULTIPLIER switch for the desired numerical value. b) The OFFSET control to approximately mid-range… c) The GAIN switch to the desired value… The CORNER FREQUENCY switch weightings follow standard decimal positional conventions. d) The BYPASS switch to OUT… e) The INPUT switch to ground ( ). Connect a dc-coupled oscilloscope, of vertical sensitivity 10mV/CM or better, or a digital voltmeter (DVM) to the instrument front panel BNC connector labeled OUT. Circuit model illustrating the relationship between a filter’s differential input and amplifier and external signal and error sources. DIFFERENTIAL INPUT AMPLIFIER 0d INPUT SIGNAL AND NOISE VOLTAGE SOURCES R SA 20 dB * (+) VA GAIN = K RCM+ VCM VB RCM- SIGNAL COMMON RSB FILTER/ BYPASS DIFF AMP - OUTPUT AMPLIFER (-) B -Vs COUPLED POWER LINE NOISE VOLTAGE OUT + RD The accuracy of the corner frequency is improved by selecting the largest possible base frequency and down scaling by the MULTIPLIER. The greatest accuracy is obtained with the largest base 400, and the 0.1X MULTIPLIER switch setting. Relative accuracy of selected 40 Hz actual corner frequency for different multiplier switch settings. B 4 0 0 BASE FREQ Msd C 0 4 0 D 0 0 4 X MULT Lsd E 0.1X 1X 10X RELATIVE TUNING ACCURACY GREATEST LESS LEAST The differential input The instrument input utilizes a differential input amplifier to reject prevalent forms of electrical interference, while presenting desirable input characteristics to the signal source requiring filtering. The differential input configuration is ideal for measuring the difference between two values rather than the values themselves. Bridge circuits utilizing strain gages, thermocouples and a variety of other types of transducers generate differential full-scale output voltages in the order of millivolts that are often superimposed upon volt-level reference and noise values. B 10 dB A The B, C and D switches combined can select base corner frequency values ranging from 1 to 499 Hz in 1 Hz steps with switch weightings as just described. COM Vo = K(VA - VB) + Vcm/CMRR : WHERE K = 1, 10 AND 10 FOR GAIN SETTINGS OF 0, 10 AND 20dB RESPECTIVELY. +Vs SEE TEXT FOR REMAINING TERMS. (+) (-) The importance of CMRR In actual system environments, each signal and power return conductor can generate an interference voltage proportional to the net conductor resistance and the electrical current level. Any such interference voltages appear as common mode signals to the amplifier, and are rejected as such. * DENOTES FRONT PANEL ACCESS AC POWER SUPPLY VP OR INTERNAL BATTERIES SIGNAL COMMON 3 1784 Chessie Lane, Ottawa, Illinois 61350 • Tel: 800/252-7074, 815/434-7800 • FAX: 815/434-8176 e-mail: [email protected] • Web Address: http://www.freqdev.com Models 900CT & 900BT Single Channel – Model 900 Series Front Panel Description Certified Location of Front Panel Terminals and Controls A B M C L D K E J I D. CORNER FREQUENCY Selector Switch (0-9): This ten position rotary switch selects the 1’s digit of the desired corner frequency between 0 and 9 in discrete increments of 1. A. POWER Status Lamp: This red LED indicates whether or not the power to the analog filter circuitry of a Model 900CT/BT Series instrument is ON. With the power switch in the ON position, the LED glows continuously indicating internal DC power levels are correct. If LED does not light when power switch is in ON position, 1) reset instrument by cycling POWER switch OFF and ON, 2) Check line fuse. E. MULTIPLIER Selector Switch: This fourposition rotary switch multiplies by a factor of either 0.1, 1.0, 10 or 100, the aggregate value set on the 3 CORNER FREQUENCY selector switches. (B, C & D) For 900BT models only: If LED is flashing, recharge batteries, approximately 30 minutes of operation remains. F. GAIN Switch: This three-position toggle switch selects an overall filter gain of 0, 10, or 20 dB. B. CORNER FREQUENCY Selector Switch (0-400Hz): This five position rotary switch selects the 100’s digit of the corner frequency designator. The switch selectable values are 0, 100, 200, 300 and 400 in five discrete steps. G. BYPASS Switch: OUT and IN setting of this two position toggle switch routes the input signal to the internal filter or around it, respectively. E.g. OUT position - no Bypass, the signal passes through the filter. In either case, the gain switch remains operational. C. CORNER FREQUENCY Selector Switch (0-90): This ten-position rotary switch selects the 10’s digit of the desired corner frequency between 0 and 90, in discrete increments of 10. H. INPUT Switch: This three position toggle configures the instrument for either differential inputs (A-B), a single-ended input (A), or input nulling ( ) which grounds both the (A) and (B) input terminals. H G F I. & J. (A) and (B) Input Terminals: This pair of shielded, female BNC connectors accept signal inputs (A) and (B). The instrument applies a non-inverting gain to input (A) and an equal but opposite inverting gain to input (B) while the GAIN switch sets the magnitude of differential gain to 0, 10, or 20 dB. The BNC shields have been internally connected to the instrument ground. K. GROUND ( ) Terminal: This “Banana” type test jack provides neat and secure access to the internal ground. This terminal is a convenient junction for grounding external system and measurement instrumentation and/or apparatus. L. OUT Terminal: This terminal is a female BNC connector. The shield on the BNC is internally connected to the instrument ground. M. OFFSET Adjust: This adjustment is intended to zero the offset that results from the instrument’s own circuitry and does not provide for wide range offset to remove dc input signals. 4 1784 Chessie Lane, Ottawa, Illinois 61350 • Tel: 800/252-7074, 815/434-7800 • FAX: 815/434-8176 e-mail: [email protected] • Web Address: http://www.freqdev.com Models 900CT & 900BT Single Channel – Model 900 Series Rear Panel Description Certified Location of Rear Panel Terminals, Controls and Labels Model 900CT O N P Model 900BT N. IDENTIFICATION LABEL: This label identifies the Model number, filter type, serial number, date of manufacture, operating power limits and fuse requirements of the instrument. O. AC POWER CONNECTION: Denotes plug and fuse location. P. POWER ON/OFF Switch: Is a twoposition toggle switch on the back panel that interrupts/completes the power circuit. Q. VOLTAGE Selector Module: For 230 Vac operation, use a screwdriver blade to pry open the module door (entry point next to window), remove the red fuse cartridge, replace the 0.2 Amp, 250 V fuse with a 0.1 Amp, 250 Volt fuse, remove the shorting clip in the other leg and replace it with a second 0.1 Amp fuse. Turn the module 180 degrees, re-insert and close the module door. The numerals 230V will now show in the module window. Reverse procedure to change back to 115V. Q 5 1784 Chessie Lane, Ottawa, Illinois 61350 • Tel: 800/252-7074, 815/434-7800 • FAX: 815/434-8176 e-mail: [email protected] • Web Address: http://www.freqdev.com Models 900CT & 900BT Single Channel – Model Transfer Function Range fc, fr Theoretical Transfer Characteristics Tuning Resolution Passband Ripple Pass Band Voltage Gain (non-inverting) Stopband Attenuation Cutoff Frequency Accuracy Stability Amplitude Phase Filter Attenuation (theoretical) Total Harmonic Distortion @ 1 kHz Wide Band Noise (5 Hz – 2 MHz) Narrow Band Noise (5 Hz – 100 kHz) 8 Pole Low Pass Filters Certified 900L8B 900L8L 8-Pole Butterworth Filter Specifications 8-Pole 8-Pole, 6 zero Bessel Elliptic 8-Pole, 6 zero Elliptic 0.1 Hz to 49.9 kHz 0.1 Hz to 49.9 kHz 0.1 Hz to 49.9 kHz 0.1 Hz to 49.9 kHz Appendix A Page 9 Appendix A Page 4 Appendix A Page 24 Appendix A Page 25 1 part in 499 within each decade 0.0 dB 1 part in 499 within each decade 0.0 dB 1 part in 499 within each decade ±0.035 dB 1 part in 499 within each decade -0.05 dB 0 ± 0.1 dB typ. 0 ± 0.2 dB max. 0 ± 0.1 dB typ. 0 ± 0.2 dB max. 0 ± 0.1 dB typ. 0 ± 0.2 dB max. 0 ± 0.1 dB typ. 0 ± 0.2 dB max. 48 dB/Octave 48 dB/Octave -80 dB typ. -100 dB typ. fc ±2% max. ±0.5% typ. ±2% max. fc ±2% max. ±0.5% typ. ±2% max. fc ±2% max. ±0.5% typ. ±2% max. fc ±2% max. ±0.5% typ. ±2% max. ±0.01%/°C typ. ±0.02%/°C max. -3 dB -360° ±0.01%/°C typ. ±0.02%/°C max. -3 dB -182° ±0.01%/°C typ. ±0.02%/°C max. -0.035 dB -323° ±0.01%/°C typ. ±0.02%/°C max. -0.05 dB -419° 0.12 dB 3.01 dB 60.0 dB 80.0 dB 1.91 dB 3.01 dB 60.0 dB 80.0 dB 0.35 dB 3.01 dB 60.0 dB 80.0 dB 0.05 dB 3.01 dB 60.0 dB 80.0 dB 0.80 fc 1.00 fc 2.37 fc 3.16 fc 900L8E 0.80 fc 1.00 fc 4.52 fc 6.07 fc 900L8EY 1.00 fr 1.13 fr 1.67 fr 1.77 fr 1.00 fr 1.06 fr 1.83 fr 2.00 fr <-90 dB typ. <-90 dB typ. <-90 dB typ. <-88 dB typ. 200µVrms typ. 200µVrms typ. 250µVrms typ. 250µVrms typ. 50µVrms typ. 50µVrms typ. 75µVrms typ. 75µVrms typ. 6 1784 Chessie Lane, Ottawa, Illinois 61350 • Tel: 800/252-7074, 815/434-7800 • FAX: 815/434-8176 e-mail: [email protected] • Web Address: http://www.freqdev.com Models 900CT & 900BT Single Channel – Model Transfer Function Range fc Theoretical Transfer Characteristics Tuning Resolution Passband Ripple Pass Band Voltage Gain (non-inverting) Stopband Attenuation Cutoff Frequency Accuracy Stability Amplitude Phase Filter Attenuation (theoretical) Total Harmonic Distortion @ 1 kHz Wide Band Noise (5 Hz – 2 MHz) Narrow Band Noise (5 Hz – 100 kHz) 8 Pole Low Pass Filters Certified 900L8D80 Filter Specifications 8-Pole, 6 zero Constant Delay 900L8D10 8-Pole, 6 zero Constant Delay 0.1 Hz to 49.9 kHz 0.1 Hz to 49.9 kHz Appendix A Page 21 Appendix A Page 22 1 part in 499 within each decade 0.15 dB 1 part in 499 within each decade 0.15 dB 0 ± 0.1 dB typ. 0 ± 0.2 dB max. 0 ± 0.1 dB typ. 0 ± 0.2 dB max. -80 dB typ. -100 dB typ. fc ±2% max. ±0.5% typ. ±2% max. fc ±2% max. ±0.5% typ. ±2% max. ±0.01%/°C typ. ±0.02%/°C max. -3 dB -306° ±0.01%/°C typ. ±0.02%/°C max. -3 dB -311° 3.01 dB 60.0 dB 80.0 dB 3.01 dB 80.0 dB 100.0 dB 1.00 fc 3.08 fc 3.57 fc 1.00 fc 4.45 fc 5.20 fc <-90 dB typ. <-88 dB typ. 200µVrms typ. 200µVrms typ. 50µVrms typ. 50µVrms typ. 7 1784 Chessie Lane, Ottawa, Illinois 61350 • Tel: 800/252-7074, 815/434-7800 • FAX: 815/434-8176 e-mail: [email protected] • Web Address: http://www.freqdev.com Models 900CT & 900BT Single Channel – Model 8 Pole High Pass Filters Certified 900H8B 900H8E 900H8EY Filter Specifications 8-Pole 8-Pole, 6 zero Butterworth Elliptic 8-Pole, 6 zero Elliptic 0.1 Hz to 49.9 kHz 0.1 Hz to 49.9 kHz 0.1 Hz to 49.9 kHz Appendix A Page 29 Appendix A Page 37 Appendix A Page 38 1 part in 499 within each decade 1 part in 499 within each decade 1 part in 499 within each decade 0.0 dB ±0.035 dB -0.05 dB Pass Band Voltage Gain (non-inverting) 0 ± 0.2 dB to.100kHz 0 ± 0.5 dB to 120kHz. 0 ± 0.2 dB to.100kHz 0 ± 0.5 dB to 120kHz. 0 ± 0.2 dB to.100kHz 0 ± 0.5 dB to 120kHz. Powert Bandwidth 120 kHz 120 kHz 120 kHz 48 dB/Octave -80 dB typ. -100 dB typ. fc ±2% max. ±0.5% typ. ±2% max. fc ±2% max. ±0.5% typ. ±2% max. fc ±2% max. ±0.5% typ. ±2% max. ±0.01%/°C typ. ±0.02%/°C max. -3 dB -360° ±0.01%/°C typ. ±0.02%/°C max. -0.035 dB -323° ±0.01%/°C typ. ±0.02%/°C max. -0.5 dB -419° 80.0 dB 60.0 dB 3.01 dB 0.00 dB 80.0 dB 60.0 dB 3.01 dB 0.03 dB 0.00 dB 100.0 dB 80.0 dB 3.01 dB 0.03 dB 0.00 dB Transfer Function Range fc, fr Theoretical Transfer Characteristics Tuning Resolution Passband Ripple Stopband Attenuation Cutoff Frequency Accuracy Stability Amplitude Phase Filter Attenuation (theoretical) Total Harmonic Distortion @ 1 kHz Wide Band Noise (5 Hz – 2 MHz) Narrow Band Noise (5 Hz – 100 kHz) 0.31 fc 0.42 fc 1.00 fc 2.00 fc 0.56 fr 0.60 fr 0.88 fr 1.00 fr 2.00 fr 0.50 fr 0.55 fr 0.94 fr 1.00 fr 2.00 fr <-88 dB typ. <-88 dB typ. <-88 dB typ. 400µVrms typ. 400µVrms typ. 500µVrms typ. 100µVrms typ. 100µVrms typ. 150µVrms typ. 8 1784 Chessie Lane, Ottawa, Illinois 61350 • Tel: 800/252-7074, 815/434-7800 • FAX: 815/434-8176 e-mail: [email protected] • Web Address: http://www.freqdev.com Models 900CT & 900BT Single Channel – General Specifications Certified Input Characteristics Input Impedance: Differential Single Ended Input Voltage: Linear Differential* Max Safe Differential Max Safe Common Mode Bias Current Common Mode Rejection ratio with 2kΩ source unbalance and 0 dB Gain Output Characteristics Full Power Bandwidth** Related Output Short Circuit Output Current Output Protection Output Impedance Offset Voltage 2 MΩ Shunted by 47pF 1 MΩ Shunted by 47pF 20V p-p (Gain Set at 0 dB) Any Continuous Value between ±100V Any Continuous Value between ±100V 30 pA typ.; 175 pA max. > 60dB, DC to 50kHz DC to 600kHz 10V p-p for RL = 50Ω 20V p-p for RL = 2kΩ ±100 mA continuous ±200 mA without damage (Short Circuit to Ground Only) 50 Ω Adjustable to Zero at Front Panel (Range ±500mV dc) Power Supply AC Line Power Operation 900CT 900BT Voltage Frequency Range-Rear Panel: 115 V 230 V Fuse 105 to 125Vac @ 50/60Hz 210 to 250Vac @ 50Hz 115 V=0.2 Amp., 230 V = 2X-0.1 Amp. Battery Operation (900BT) Time for full Charge Battery Life Battery Charger Charge Status Indicator (Front Panel) Battery Operation 10 – 12 hours Approx. 500 Charge/Discharge Cycles Automatic Uninterruptible 3 Status Levels 6 Hours typ. Temperature Operating Temperature: Storage Temperature: 0 °C to +50 °C -25 °C to +70 °C Mechanical Dimensions Weight 900CT 900CT Case Material Color 10 Watts max. 15 Watts max. 3.7"H x 8.66"W x 10.6"D 9.4cmH x 22.0cmW x 27.0cmD 3.5 lbs; 0.157 kgs 4.9 lbs; 0.219 kgs ABS plastic Light Gray * Signal plus common mode voltage cannot exceed 20V peak to peak for a linear output. ** Output characteristics of input amplifier with filter in BYPASS mode. 9 1784 Chessie Lane, Ottawa, Illinois 61350 • Tel: 800/252-7074, 815/434-7800 • FAX: 815/434-8176 e-mail: [email protected] • Web Address: http://www.freqdev.com Models 900CT & 900BT Single Channel – Certified Ordering Information A. AVAILABLE MODELS 1. 900CT 2. 900BT 1 Standard AC powered model 1 AC powered with battery powered option 2 FILTER TRANSFER FUNCTIONS AVAILABLE B. LOW-PASS BUTTERWORTH 1. 900L8B BESSEL 2 900L8L ELLIPTIC 3. 900L8E 4. 900L8EY CONSTANT DELAY 5. 900L8D80 6. 900L8D10 C. HIGH PASS BUTTERWORTH ELLIPTIC 7. 8. 9. 900H8B 900H8E 900H8EY 8-pole 8-pole 8-pole, 6 zero elliptic, 1.77, 80 dB 8-pole, 6 zero elliptic, 2.00, 100 dB 8-pole, constant delay 80 dB 8-pole, constant delay 100 dB 8-pole 8-pole, 6 zero elliptic, 1.77, 80 dB 8-pole, 6 zero elliptic, 2.00, 100 dB ORDERING INFORMATION 2 Filter Type Transfer Function L – Low – Pass H – High – Pass B – Butterworth L – Bessel D80 – Constant Delay (-80dB) D10 – Constant Delay (-100dB) E - elliptic 1.77 (-80dB) EY – elliptic 2.00 (-100dB) 900CT/900L8L Model 1 C – Standard AC Power B – AC Powered, with Battery Power Option Poles 8 NOTE: 1. 2. See page 5, item “Q” Voltage selector Module. At time of shipment, Voltage is pre-selected in the 115 VAC position. For 230 VAC operation, this module must be rotated 180 degrees and an additional fuse must be added. All filters tunable from 0.1 Hz to 49.9 kHz. We hope the information given here will be helpful. The information is based on data and our best knowledge, and we consider the information to be true and accurate. Please read all statements, recommendations or suggestions herein in conjunction with our conditions of sale, which apply, to all goods supplied by us. We assume no responsibility for the use of these statements, recommendations or suggestions, nor do we intend them as a recommendation for any use, which would infringe any patent or copyright. IN-00900CT/BT-00 10 1784 Chessie Lane, Ottawa, Illinois 61350 • Tel: 800/252-7074, 815/434-7800 • FAX: 815/434-8176 e-mail: [email protected] • Web Address: http://www.freqdev.com