SCM5B38 Strain Gage Input Modules, Wide Bandwidth FEATURES The SCM5B modules are designed with a completely isolated computer side circuit which can be floated to 50V from Power Common, pin 16. This complete isolation means that no connection is required between I/O Common and Power Common for proper operation of the output switch. If desired, the output switch can be turned on continuously by simply connecting pin 22, the Read-Enable pin to I/O Common, pin 19. INTERFACES TO 100 THRU 10k, FULL-BRIDGE, HALF-BRIDGE, OR QUARTER-BRIDGE STRAIN GAGES HIGH LEVEL VOLTAGE OUTPUTS 1500Vrms TRANSFORMER ISOLATION The SCM5B38 can interface to full-bridge or half-bridge transducers with a nominal resistance of 100 to 10k. A matched pair of bridgecompletion resistors (to 1mV at +10V excitation) allows use of low cost half-bridge or quarter-bridge transducers (Figures 2, 3, 4). The 10kHz bandwidth allows measurement of high speed processes such as vibration analysis. ANSI/IEEE C37.90.1-1989 TRANSIENT PROTECTION INPUT PROTECTED TO 240VAC CONTINUOUS FULLY ISOLATED EXCITATION SUPPLY 100dB CMR Strain Gage excitation is provided from the module by a very stable 10V or 3.333V source. The excitation supply is fully isolated, allowing the amplifier inputs to operate over the full range of the excitation voltage. This feature offers significant flexibility in real world applications. Full scale sensitivities of 2mV/V, 3mV/V or 10mV/V are offered as standard. With 10V excitation, this results in 20mV, 30mV or 100mV full scale input range producing 5V full scale output. 10kHz SIGNAL BANDWIDTH 0.08% ACCURACY 0.02% LINEARITY 1V/C DRIFT CSA CERTIFIED, FM APPROVED, CE COMPLIANT MIX AND MATCH SCM5B TYPES ON BACKPANEL DESCRIPTION Each SCM5B38 Strain Gage input module provides a single channel of Strain Gage input which is filtered, isolated, amplified, and converted to a high level analog voltage output (Figure 1). This voltage output is logic switch controlled, which allows these modules to share a common analog bus without the requirement of external multiplexers. 4 +EXC Strain Gage The input signal is processed through a pre-amplifier on the field side of the isolation barrier. This pre-amplifier has a gain-bandwidth product of 5MHz and is bandwidth limited to 10kHz. After amplification, the input signal is chopped by a proprietary chopper circuit. Isolation is provided by transformer coupling, again using a proprietary technique to suppress transmission of common mode spikes or surges. The module is powered from +5VDC, 5%. Special input circuits on the SCM5B38 module provide protection of the signal inputs and the isolated excitation supply up to 240VAC. LPF IsochopperTM Amplifier Pat Pending 4 +In 6 3 5 -In Surge Suppression and Protection 20 VOUT 19 +V 2 Isolated Excitation Source 3 -EXC LPF 1 I/O Common -V 22 Isolated Computer-Side Power RD EN\ Backpanel Term Block 1 2 +V -V 17 Isolated Field-Side Power FIGURE 1. SCM5B38 Block Diagram. DATAFORTH A Burr-Brown Company (R) Call 800-444-7644 For Information and Assistance 60 Power Oscillator 16 +5V Power Common A FIGURE 2. Full Bridge Connection. = +25C and +5V power. Module Input Range Input Bias Current Input Resistance Normal Power Off Overload Signal Input Protection Continuous Transient Excitation Output (-02, -04, -05, -07) Excitation Output (-01, -03, -06) Excitation Load Regulation Excitation Stability Half Bridge Voltage Level (-04) Half Bridge Voltage Level (-03) Isolated Excitation Protection Continuous Transient CMV, Input to Output Continuous Transient CMR (50 or 60Hz) NMR (-3dB at 10kHz) Accuracy(2) Nonlinearity Stability Input Offset Output Offset Gain Full Bridge SCM5B38-01, -02, -05, -06, -07 Half Bridge SCM5B38-03, -04 10mV to 100mV 0.3nA * * 50M 40k 40k * * * 240Vrms max ANSI/IEEE C37.90.1-1989 * * +10V 3mV +3.333V 2mV 5ppm/mA 15ppm/C NA NA * * * * +5V 1mV +1.667V 1mV 240Vrms max ANSI/IEEE C37.90.1-1989 * * 1500Vrms max ANSI/IEEE C37.90.1-1989 100dB 120dB per Decade above 10kHz * * * * 0.08% Span 10V RTI(3) 0.02% Span * * 1V/C 40V/C 25ppm of Reading/C * * * Output Range Output Resistance Output Protection Output Selection Time (to 1mV of VOUT) Output Current Limit 2Vrms * 10kHz 35s 250s * * * 5V 50 Continuous Short to Ground 6s at Cload = 0 to 2000pF * * * * Rg (1) 3 +In 6 2 -In Rg (1) 5 Rg (1) 1 3 SCM5B38-01 SCM5B38-02 SCM5B38-05 SCM5B38-06 SCM5B38-07 -EXC Backpanel Terminal Block FIGURE 3. Half Bridge Connection. +EXC Rg 4 4 (1) R1 +In -In Rg(1) 3 2 1 VEXC 6 5 R2 3 -EXC SCM5B38-03 SCM5B38-04 R1 = R2 FIGURE 4. Quarter Bridge Connection. +EXC 4 Rg R1 +In +0.8V +2.4V +36V 0.5A * * * * Power Supply Voltage Power Supply Current Power Supply Sensitivity +5VDC 5% 170mA Full Exc. Load, 70mA No Exc. Load 2V/% RTI(3) * * * Mechanical Dimensions 2.28" x 2.26" x 0.60" (58mm x 57mm x 15mm) * -40C to +85C -40C to +85C 0 to 95% Noncondensing EN50081-1, ISM Group 1, Class A (Radiated, Conducted) EN50082-1, ISM Group 1, Class A (ESD, RF, EFT) * * * * Environmental Operating Temperature Range Storage Temperature Range Relative Humidity Emissions 4 (1) 8mA Output Enable Control Max Logic "0" Min Logic "1" Max Logic "1" Input Current, "0,1" SCM5B38-01 SCM5B38-02 SCM5B38-03 SCM5B38-04 SCM5B38-05 SCM5B38-06 SCM5B38-07 VEXC Rg (1) NC 0.4Vrms 10mVp-p Bandwidth, -3dB Rise Time, 10 to 90% span Setting Time, to 0.1% MODEL (10kHz) 4 Backpanel Terminal Block Noise Input, 0.1 to 10Hz Output, 100kHz Immunity 4 +EXC SCM5B SPECIFICATIONS Typical at T NC -In 3 2 5 R3 1 -EXC Customer Supplied VEXC 6 R2 3 R1 = R2 SCM5B38-03 SCM5B38-04 Backpanel Terminal Block * Same as -01, -02, -05, -06, -07 modules. NOTES: (1) Strain element. (2) Includes excitation error, nonlinearity, hysteresis and repeatability. (3) Referenced to input. * INPUT BRIDGE TYPE INPUT RANGE EXCITATION OUTPUT RANGE Full Bridge Full Bridge Half Bridge Half Bridge Full Bridge Full Bridge Full Bridge 100 to 10k 300 to 10k 100 to 10k 300 to 10k 300 to 10k 100 to 10k 300 to 10k 3.333V at 3mV/V Sensitivity 10.0V at 3mV/V Sensitivity 3.333V at 3mV/V Sensitivity 10.0V at 3mV/V Sensitivity 10.0V at 2mV/V Sensitivity 3.333V at 10mV/V Sensitivity 10.0V at 10mV/V Sensitivity -5V to +5V -5V to +5V -5V to +5V -5V to +5V -5V to +5V -5V to +5V -5V to +5V 61 Call 800-444-7644 For Information and Assistance ORDERING INFORMATION DATAFORTH A Burr-Brown Company (R)