Model 950 Single Channel- Tunable Filter Instruments Certified Description Frequency Devices’ Model 950 instruments furnish the user with an 8-pole low-pass or high-pass filter that is tunable by front panel controls. The controls allow the user to select a corner frequency between 10 Hz and 50 kHz with 6 steps from each of two selectable ranges. The instrument exhibits an input impedance of 1 Meg Ω 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 Meg Ω 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. Standard operational features include: 1) Adjustable Frequency Control Available Low-Pass Models: . . . . . . . . . . . . . Page 950L8B 8-pole Butterworth. . . . . . . . . . . . . . . . . . 3 950L8L 8-pole Bessel . . . . . . . . . . . . . . . . . . . . . 3 2) Differential Input Amplifiers 3) Adjustable Gain Control 4) Off-set Adjustment Available High-Pass Models: . . . . . . . . . . . . . Page 950H8B 8-pole Butterworth. . . . . . . . . . . . . . . . . . 3 5) BNC Connectors for Signal I/O General Specifications: . . . . . . . . . . . . . . . . . . . 6 Compact size and manual rotary switch front panel controls make 950 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 1 1784 Chessie Lane, Ottawa, IL 61350 • Tel: 800/252-7074, 815/434-7800 • FAX: 815/434-8176 e-mail: [email protected] • Web Address: http://www.freqdev.com Model 950 Tunable Filter Instruments BLOCK DIAGRAM GAIN (dB) INPUT 10dB 0dB 20dB A A-B A + OUT DIFF AMP 8-POLE TUNABLE FILTER OUTPUT AMP OFFSET NULLED B CORNER FREQUENCY TUNING OFFSET TYPICAL FRONT PANEL BNC CONNECTOR TYPICAL ADJUSTMENT FUNCTION ON 950 50 100 TUNEABLE ACTIVE FILTER INPUT A A-B B 10 OUT 10 - 0 GND CORNER 200 FREQUENCY 500 IN Hz OFFSET GAIN (dB) A 20 20 + R x100 A N G E x1 2 1784 Chessie Lane, Ottawa, IL 61350 • Tel: 800/252-7074, 815/434-7800 • FAX: 815/434-8176 e-mail: [email protected] • Web Address: http://www.freqdev.com Model 950 Tunable Filter Instruments Model 950L8B 950L8L Model Product Specifications Low-Pass Low-Pass Transfer Function 8-Pole, Butterworth 8-Pole, Bessel Transfer Function 8-Pole, Butterworth Range fc 10 Hz to 50.0 kHz 10 Hz to 50.0 kHz Range fc 10 Hz to 50.0 kHz Theoretical Transfer Characteristics Appendix A Page 9 Appendix A Page 4 Theoretical Transfer Characteristics Appendix A Page 29 Passband Ripple 0.0 dB 0.0 dB Passband Ripple 0.0 dB High-Pass (theoretical) DC Voltage Gain (non-inverting) Stopband Attenuation Rate Cutoff Frequency Accuracy Stability Amplitude Phase Filter Attenuation 950H8B (theoretical) 0 ± 0.1 dB typ. 0 ± 0.2 dB max. 0 ± 0.1 dB typ. 0 ± 0.2 dB max. Voltage Gain (non-inverting) Power Bandwidth 120 kHz Stopband Attenuation Rate 48 dB/Octave 48 dB/Octave 48 dB/Octave fc ± 2% max. ± 0.05% typ. ± 2% max ± 0.01%/°C typ. ± 0.02%/°C max. -3 dB -360° fc ± 2% max. ± 0.05% typ. .± 2% max. ± 0.01%/°C typ. ± 0.02%/°C max. -3 dB -182° Cutoff Frequency Accuracy 0.12 dB 3.01 dB 60.0 dB 80.0 dB 1.91 dB 3.01 dB 60.0 dB 80.0 dB Filter Attenuation 0.80 fc 1.00 fc 2.37 fc 3.16 fc 0.80 fc 1.00 fc 4.52 fc 6.07 fc 0 ± 0.2 dB to 100 kHz 0 ± 0.5 dB to 120 kHz Stability Amplitude Phase fc ± 2% max. ± 0.05% typ. ± 2% max. ± 0.01%/°C typ. ± 0.02%/°C max. -3 dB -360° 80.0 dB 60.0 dB 3.01 dB 0.00 dB Total Harmonic Distortion @ 1 kHz <-90 dB typ. <-90 dB typ. Total Harmonic Distortion @ 1 kHz <-88 dB typ. Narrow Band Noise 50 mVrms typ. 50 mVrms typ. Narrow Band Noise 100 mVrms typ. (5 Hz - 100 kHz) (5 Hz - 100 kHz) 3 1784 Chessie Lane, Ottawa, IL 61350 • Tel: 800/252-7074, 815/434-7800 • FAX: 815/434-8176 e-mail: [email protected] • Web Address: http://www.freqdev.com 0.31 fc 0.42 fc 1.00 fc 2.00 fc Model 950 Location of Front Panel Terminals and Controls Location of Front Panel Terminals and Controls ON 950 A 50 100 TUNEABLE ACTIVE FILTER INPUT A C&D A-B 10 A B 20 GND 10 G OUT 0 CORNER 200 FREQUENCY 500 IN Hz OFFSET GAIN (dB) B 20 + R x100 A N G E x1 I H F E Location of Rear Panel Terminals and Controls K APR.01 SN: 00105 950L8L SELECT 115v 230v FUSE (250V 0.1A) (250V 0.1A) NOM. FREQ. 60 Hz 50 Hz corcom J L M WARNING: Do not remove covers, no user serviceable parts inside. Contact: Frequency Devices for service, [email protected] MADE IN U.S.A REAR PANEL FRONT PANEL A. POWER Status Lamp: This red LED indicates whether or not the power to the analog filter circuitry of a Model 950 instrument is on. B. INPUT Switch: This three position toggle configures the instrument for either differential inputs (A-B), a singleended input (A), or input nulling (GND) which grounds both the (A) and (B) input terminals. C. & D. (A) and (B) Input Terminals: This pair of shielded, female BNC connectors accept signal inputs (A) and (B). The instrument applies a noninverting 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. F. 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. G. CORNER FREQUENCY Selector Switch (10-500Hz): This six position rotary switch selects the digit value of the corner frequency. The switch selectable values are 10, 20, 50, 100, 200 and 500, H. MULTIPLIER Selector Switch: This two-position toggle switch multiplies by a factor of either 1 or 100x, the value set on the CORNER FREQUENCY selector switch. I. OUT Terminal: This terminal is a female BNC connector. The shield on the BNC is internally connected to the instrument ground. E. GAIN Switch: This three-position toggle switch selects an overall filter gain of 0, 10, or 20dB. 4 J. IDENTIFICATION LABEL: This label identifies the date of manufacture, serial number, filter type and operating power requirements. K. POWER CONNECTION: power plug location. Denotes L. POWER ON/OFF Switch: A twoposition toggle switch on the back panel Power Module that interrupts/completes the power circuit. M. Voltage Selector Module: 115V Operation The power module window shows the operating voltage (115V or 230V). At time of shipment, the voltage window will be set to the 115V position. 230V Operation For 230V operation, use a small flathead screwdriver to pry open the fuse module door. Remove the fuse cartridge, fuse clip and single fuse for 115V operation. Install two 5 X 20 mm 250V, 0.1A fuses into the fuse cartridge, rotate and insert fuse cartridge so 230V is visible in fuse module door when closed. 1784 Chessie Lane, Ottawa, IL 61350 • Tel: 800/252-7074, 815/434-7800 • FAX: 815/434-8176 e-mail: [email protected] • Web Address: http://www.freqdev.com Model 950 Operation and Application Guide Lines The Differential Input Initial Setup Select desired operating voltage 115 Vac or 230 Vac. See note "N" page four. Set the OFFSET control for a zero-volt reading on the scope. Set the POWER ON/OFF Switch to ON. A continuously lit POWER lamp indicates power applied. 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. To perform initial adjustment and/or operational testing, set the remaining front panel controls as follows: a) The CORNER FREQUENCY switch and the MULTIPLIER to the desired corner frequency. 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 55=OVdc. This completes preliminary test and adjustment. The instrument 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) The OFFSET control to approximately mid-range. Corner Frequency Selection The importance of CMRR To select a corner frequency, simply set the CORNER FREQUENCY switch and the MULTIPLIER switch for the desired numerical value. 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. c) The GAIN switch to the desired value. e) The INPUT switch to ground (GND). 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 relationship between filter's differential input amplifier and external signal and error sources. 0d B INPUT SIGNAL AND NOISE VOLTAGE SOURCES RSA DIFFERENTIAL INPUT AMPLIFIER 10 dB * 20 A dB * (+) VA GAIN = K RCM+ VCM RCM- SIGNAL COMMON RSB VP - (±) Vo = K(VA - VB) + Vcm/CMRR : WHERE K = 1, 10 AND 10 FOR GAIN SETTINGS B * COUPLED POWER LINE NOISE VOLTAGE OUTPUT AMPLIFER DIFF AMP RD VB * OUT + OF 0, 10 AND 20dB RESPECTIVELY. ±Vs (±) COM +Vs (+) SEE TEXT FOR REMAINING TERMS. * DENOTES FRONT PANEL ACCESS AC POWER SUPPLY SIGNAL COMMON 5 1784 Chessie Lane, Ottawa, IL 61350 • Tel: 800/252-7074, 815/434-7800 • FAX: 815/434-8176 e-mail: [email protected] • Web Address: http://www.freqdev.com Model 950 Specifications (@25°C and rated Power Input) Typical Common Mode Rejection Ratio 0 2 MΩ Shunted by 47pF 1 MΩ Shunted by 47pF -10 Bessel filter type set to 50 kHz filter corner frequency, 0 dB gain setting. -20 -30 20V p-p (Gain Set at 0 dB) Any Continuous Value between ±75V Any Continuous Value between ±75V 4 nA typ.; 20 nA max. dB dB(RMS) (RMS) 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 -40 -50 -60 -70 -80 > 60dB, dc to 50kHz -90 -100 10 100 1000 10000 100000 Frequency (Hz) Frequency (Hz) Related Output Short Circuit Output Current Output Protection Output Impedance Offset Voltage dc to 50kHz 10V p-p for RL = 50W 20V p-p for RL = 2kW +/-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 Operation: Power Voltage Frequency Range-Rear Panel: 115 V 230 V Fuse 105 to 125Vac @ 50/60Hz 210 to 250Vac @ 50Hz 0.1 Amp Temperature Operating Temperature: Storage Temperature 0 °C to +50 °C -25 °C to +70 °C Mechanical Dimensions Weight Case Material Color Typical Output Noise 0 Bessel filter type set to 50 kHz filter corner frequency, 0 dB gain setting, input grounded. -20 -40 dBdB(re:1V RMS) (re:1V RMS) Output Characteristics Full Power Bandwidth -60 -80 -100 -120 -140 10 6 Watts max. 100 1000 10000 100000 Frequency (Hz) Frequency (Hz) 2.375"H x 7.0"W x 8.3"D 6.03cmH x 17.75cmW x 21.08cmD 1.5 lbs; 0.68 kgs. ABS plastic PC Bone * Signal plus common mode voltage cannot exceed 20V peak for a linear output. 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-00950-00 6 1784 Chessie Lane, Ottawa, IL 61350 • Tel: 800/252-7074, 815/434-7800 • FAX: 815/434-8176 e-mail: [email protected] • Web Address: http://www.freqdev.com 8-Pole Bessel Appendix A Low-Pass Theoretical Transfer Characteristics 1 f/fc Amp Phase Delay (Hz) (dB) (deg) (sec) 0.00 0.00 0.00 .506 0.10 -0.029 -18.2 .506 0.20 -0.117 -36.4 .506 0.30 -0.264 -54.7 .506 0.40 -0.470 -72.9 .506 0.50 -0.737 -91.1 .506 0.60 -1.06 -109 .506 0.70 -1.45 -128 .506 0.80 -1.91 -146 .506 0.85 -2.16 -155 .506 0.90 -2.42 -164 .506 0.95 -2.71 -173 .506 1.00 -3.01 -182 .506 -3.67 1.10 -200 .506 -4.40 1.20 -219 .506 -5.20 1.30 -237 .506 1.40 -6.10 -255 .505 1.50 -7.08 -273 .504 1.60 -8.16 -291 .502 1.70 -9.36 -309 .498 1.80 -10.7 -327 .492 1.90 -12.1 -345 .482 2.00 -13.7 -362 .468 2.25 -18.1 -402 .417 2.50 -23.1 -436 .352 2.75 -28.3 -465 .291 3.00 -33.4 -489 .241 3.25 -38.3 -509 .201 3.50 -43.1 -526 .170 4.00 -51.8 -552 .126 5.00 -66.8 -587 .077 6.00 -79.2 -610 .052 7.00 -89.8 -626 .038 8.00 -99.0 -638 .029 9.00 -107 -647 .023 10.0 -114 -655 .018 Frequency Response Amp (dB) 0 -40 -60 -80 -100 0.1 2 3 4 5 6 78 1.0 2 3 4 5 6 7 10.0 Normalized Frequency(f/fc) Delay (Normalized) Delay (sec) 1.0 0.5 0.0 0.1 0.15 2 3 4 5 6 7 89 1.0 1.5 Normalized Time (1/f sec) Step Response (V/V) Step Response 1.Normalized Group Delay: The above delay data is normalized to a corner frequency of 1.0Hz.The actual delay is the normalized delay divided by the actual corner frequency (fc). Actual Delay = -20 Normalized Delay 1.2 1.0 0.8 0.6 0.4 0.2 -0.0 -0.2 0 1 2 3 4 Normalized Time (1/f sec) Actual Corner Frequency (fc) in Hz 7 1784 Chessie Lane, Ottawa, IL 61350 • Tel: 800/252-7074, 815/434-7800 • FAX: 815/434-8176 e-mail: [email protected] Web Address: http://www.freqdev.com Fax on Demand: 978/521-5178 5 Low-Pass 8-Pole Appendix A Butterworth Theoretical Transfer Characteristics 1 f/fc Amp Phase Delay (Hz) (dB) (deg) (sec) 0.00 0.00 0.00 .816 0.10 0.00 -29.4 .819 0.20 0.00 -59.0 .828 0.30 0.00 -89.1 .843 0.40 0.00 -120 .867 0.50 0.00 -152 .903 0.60 -0.001 -185 .956 0.70 -0.014 -221 1.04 0.80 -0.121 -261 1.19 0.85 -0.311 -283 1.29 0.90 -0.738 -307 1.40 0.95 -1.58 -333 1.48 1.00 -3.01 -360 1.46 1.10 -7.48 -408 1.17 1.20 -12.9 -445 .873 1.30 -18.2 -472 .672 1.40 -494 .540 -23.4 1.50 -511 .448 -28.2 1.60 -526 .380 -32.7 1.70 -539 .328 -36.9 1.80 -550 .287 -40.8 1.90 -44.6 -560 .253 2.00 -48.2 -568 .226 2.25 -56.3 -586 .174 2.50 -63.7 -600 .139 2.75 -70.3 -611 .113 3.00 -76.3 -621 .094 3.25 -81.9 -629 .080 3.50 -87.1 -635 .069 4.00 -96.3 -646 .052 5.00 -112 -661 .033 6.00 -125 -671 .023 7.00 -135 -678 .017 8.00 -144 -683 .013 9.00 -153 -687 .010 10.0 -160 -691 .008 Frequency Response Amp (dB) 0 -60 -100 0.1 Delay (sec) 2.0 2 3 4 5 6 78 1.0 2 3 4 5 67 Normalized Frequency(f/fc) 10.0 Delay (Normalized) 1.0 0.0 0.1 0.15 2 3 4 5 6 7 8 9 1.0 1.5 Normalized Time (1/f sec) Step Response (V/V) Step Response 1.2 1.0 0.8 0.6 0.4 0.2 -0.0 0 Normalized Delay Actual Corner Frequency (fc) in Hz -40 -80 1.Normalized Group Delay: The above delay data is normalized to a corner frequency of 1.0Hz.The actual delay is the normalized delay divided by the actual corner frequency (fc). Actual Delay = -20 8 1 2 3 4 Normalized Time (1/f sec) 1784 Chessie Lane, Ottawa, IL 61350 • Tel: 800/252-7074, 815/434-7800 • FAX: 815/434-8176 e-mail: [email protected] Web Address: http://www.freqdev.com 5 High-Pass 8-Pole Appendix A Butterworth Theoretical Transfer Characteristics 1 f/fc Amp Phase Delay (Hz) (dB) (deg) (sec) 0.10 -160 691 0.819 0.20 -112 661 0.828 0.30 -83.7 631 0.843 0.40 -63.7 600 0.867 0.50 -48.2 568 0.903 0.60 -35.5 535 .956 499 0.70 -24.8 1.04 459 0.80 -15.6 1.19 437 0.85 -11.6 1.29 413 0.90 -8.06 1.40 0.95 -5.15 386 1.48 360 1.00 -3.01 1.46 275 1.20 -0.229 0.873 226 1.40 -0.020 0.540 -0.002 194 1.60 0.380 170 1.80 0.00 0.287 152 0.00 2.00 0.226 0.139 120 0.00 2.50 0.00 99.2 0.094 3.00 0.052 0.00 74.0 4.00 5.00 0.00 59.0 0.033 49.0 0.023 6.00 0.00 0.00 42.1 0.017 7.00 0.00 36.8 0.013 8.00 0.00 32.7 0.010 9.00 10.0 0.00 29.4 0.008 Frequency Response Amp (dB) 0 -20 -40 -60 -80 -100 0.1 2 3 4 5 6 78 1.0 2 3 4 5 6 7 10.0 Normalized Frequency(f/fc) 1.Normalized Group Delay: The above delay data is normalized to a corner frequency of 1.0Hz.The actual delay is the normalized delay divided by the actual corner frequency (fc). Actual Delay = Normalized Delay Actual Corner Frequency (fc) in Hz 9 1784 Chessie Lane, Ottawa, IL 61350 • Tel: 800/252-7074, 815/434-7800 • FAX: 815/434-8176 e-mail: [email protected] Web Address: http://www.freqdev.com