High Performance Signal Conditioner For Kulite Sensor Products
8Pages

KSC-2 HIGH PERFORMANCE SIGNAL CONDITIONER FOR KULITE SENSOR PRODUCTS KULITE KSC-2 FEATURES • Two channels per system • 0.1% overall DC accuracy • 6-pole low-pass filters with programmable flat/pulse characteristics • Cutoff frequencies programmable from 500 Hz to 127.5 kHz • Patent pending REZCOMP® transducer resonance compensation to extend useable bandwidth of resonant sensors (Option C3) • Precise digital calibration of gain, excitation and DC offset • Bipolar Constant Voltage Excitation with Remote Sense • Unipolar Excitation Mode to power internally regulated transducers • Automatic or manual bridge balance/suppress • Balanced Differential Input • Programmable AC/DC input coupling • 7 nV/ √Hz maximum input noise • Pre-Filter Gain: x1 to x128 in binary steps • Post-Filter Gain: x1/16 to x16 with 0.025% minimum resolution • Input and output overload detection with programmable threshold • Front-panel auto-balance and overload reset with fault LED indicators • Calibration/Zero Input • USB control interface with field upgradable firmware • GUI interface for control of up to 8 KSC-2 units • Compact stackable chassis design with link kit to lock units together • Side-by-side rack-mount option KSC-2 DESCRIPTION The KSC-2 is a compact, rugged dual-channel high precision amplifier/filter with programmable constant voltage excitation optimized for conditioning Kulite pressure sensors and microphone products. Fully programmable bipolar excitation with remote sense provides voltage for bridge type sensors while a unipolar excitation mode is supplied to condition sensors having internal regulation. Automatic or manual balance modes are supported. A low-noise, high common-mode rejection balanced differential input is supplied with programmable AC/DC input coupling. Sharp, programmable precision low-pass filters support two response characteristics that are optimized for making time domain or frequency domain measurements. Amplification is distributed as pre and post filter gain, allowing for elimination of out-of-band energy such as transducer resonant peaking that can cause non-linearities due to clipping of the amplifier. Overload detectors alert the user to output overloads as well as pre-filter overloads that may be masked by the low-pass filter. The KSC-2 features an optional patent pending REZCOMP® transducer resonant compensation technology that extends the useable frequency response of sensors with recess mounting, device packaging ® or seismic resonances. Based on a characterization of the sensor Q and resonant frequency, the REZCOMP technique extends the usable sensor bandwidth to as much as 80% of the sensor resonant frequency, or in some cases, even beyond the sensor resonant frequency. A high level command interface is available to control the KSC-2 via USB 2.0. A spreadsheet style graphical user interface is supplied to control up to eight KSC-2 units as a single system. Configurations may be saved/recalled from the host computer. Settings may be saved to non-volatile memory for field deployment without a host computer. Front panel LED indicators alert the user to overloads, excitation and autobalance status. In addition, autobalance can be initiated via a momentary front panel switch. The KSC-2 is supplied with an external AC to DC universal supply or may be powered using an external 10 to 30 VDC input. KULITE SEMICONDUCTOR PRODUCTS, INC. • One Willow Tree Road • Leonia, New Jersey 07605 • Tel: 201 46

KSC-2 CONSTANT VOLTAGE EXCITATION SUPPLY (CONTINUED) Input Connector: Unipolar Mode: 9-Pin female D-Sub at front panel of card (2 ea.) Channel Input Wires: Current: 30 mA, short circuit protected. ±SIG (2); ±EXC (2); ±SEN (2); SHLD (1); GND; 5th Wire Sensor Temperature Output (1) Suppress (Unipolar EXC Mode Only): KSC-2 CONSTANT VOLTAGE EXCITATION SUPPLY Transducer DC output is automatically suppressed using voltage insertion at the amplifier input. Type: Programmable Constant Voltage Excitation Modes: Automatic or Manual Entry Mode: Programmable Bipolar or Unipolar Bipolar Mode: Pre-Filter...

KSC-2 INPUT CHARACTERISTICS Type: Balanced differential input with programmable AC/DC coupling Maximum Input Level: ±10 Vpk (common mode and normal mode signals) Level vs Frequency: ±10 Vpk for f < 127.5 kHz; ±10 Vpk x (127.5 kHz/f) for f >127.5 kHz Input Impedance: 10 MQ per side Drift: 1 pV/°C, RTI CMRR (input gain >x16): 110 dB, DC to 1000 Hz Spectral Noise: 7 nV/ VHz at 1 kHz and pre-filter gain >64 Prog. AC Coupling Freq: 0.25 Hz (3.01 dB), 2-pole Input Protection: 24 V continuous KSC-2 AMPLIFIER CHARACTERISTICS Pre-Filter Gain: x1 to x128 in x2 steps with overload detection (10...

FLAT/PULSE LOW-PASS FILTERS Like the Butterworth low-pass filter, the LP6F has a non-linear phase response with 60 degrees of phase distortion at the cutoff frequency. Phase (Degrees) LP6F Phase Response and Phase Distortion Phase Distortion The LP6F and LP6P 6-pole low-pass filters have the versatility to address applications in either the time or frequency domain. Simply program the filter characteristic to match your measurement requirements. The LP6F FLAT mode characteristic has a pass-band amplitude response nearly identical to the 6-pole Butterworth yet has much sharper roll-off...

For the time domain, the LP6P PULSE mode low-pass filter has excellent transient response and phase linearity required for time domain applications such as transient (shock) measurements and time domain waveform analysis. When used for anti-aliasing applications, the LP6F provides more useable bandwidth for a given sampling frequency. LP6F Attenuation of Aliases vs Sampling Frequency KULITE SEMICONDUCTOR PRODUCTS, INC. Page 5

KSC-2 TRANSDUCER COMPENSATOR (OPTION C3) CHARACTERISTICS Transducer Cavity Resonance Compensator: Patent pending transducer cavity resonance compensation for sensor as characterized by Q and resonant frequency (Fr). Compensation Q: 1 to 20 in 0.1 steps; 20 to 50 in 0.5 steps Q ≤ 10: ±1.25 dB; 0.6 Fr < f < 1.7 Fr or 255 kHz whichever is less Q > 10: ±0.125 dB * Q; 0.6 Fr < f < 1.7 Fr or 255 kHz whichever is less Compensation Frequencies (Fr): Low-Range: 10 Hz to 2.55 kHz in 10 Hz steps Mid-Range: 2.6 kHz to 51 kHz in 200 Hz steps Phase Match: Amplitude Match: Compensator Off: Compensator may...