New 5-in-1 PC-hosted test oscilloscope features signature analysis

The Syscomp SIG-101 signature analyzer, a new PC-based two-channel 200kHz oscilloscope is now available from Saelig. Sampling at 2MSa/s, the instrument includes an arbitrary waveform generator and an 8-bit digital I/O port. Building on the CGR-101, its successful predecessor, the SIG-101 also adds calibrated signature techniques to the oscilloscope waveform display capabilities for quickly troubleshooting circuit boards. Unlike most PC-based oscilloscopes with 8-bit A/D sampling, the SIG-101 has an 11-bit A/D that gives eight times more detail, and the built-in 12-bit 200kHz arbitrary waveform signal generator can be used to create swept, stationary, or noise test signals, or provide PWM outputs. The oscilloscope and waveform generator can be combined to provide Vector Network Analysis capability, yielding Bode plots that graph the frequency response of a circuit. The Syscomp SIG-101 also provides calibrated signature analysis with a wide amplitude and frequency range. Signature analysis is a powerful technique for detecting faults on PCBs: an AC voltage is injected into the test point of a circuit board and the analyzer then plots the voltage and resultant current on an X-Y display. This display is a 'signature' of the circuit operation, which can be compared against a known 'good' pattern or board. If the patterns do not match, the test board is defective. For example, when testing a node, a capacitor will show an ellipse, a resistor shows a straight line at an angle, a diode shows the characteristic exponential curve. Signature analysis is popular in production test because it requires no understanding of the circuit operation, and so it can be used by unskilled technical personnel. The Syscomp SIG-101 represents an advance over existing signature analysis instruments: it costs a fraction of existing signature analysis instruments, and the frequency range of the test signal is continuous, extended over a wide range, allowing a wider range of useful measurements. The test voltage and measured current are calibrated, so the results can be translated into accurate component values. Signature and other waveforms can be saved, retrieved, and compared. All functions can be controlled via a USB2.0-connection from a computer running Windows, Linux, or Mac operating systems, using the open-source GUI software provided. The SIG-101 can be used for production test, education, or for general-purpose measurements for field technicians and engineers.