Fairport, NY: Saelig Company, Inc. (www.saelig.com) has announced improvements to the Cleverscope CS448 – a unique isolated high common-mode rejection ratio (CMRR) four-channel 200MHz 14-bit oscilloscope. The CS448 has been designed to measure high voltages – now up to 1600V – for fast slew-rate signals such as those in a full or three-phase power electronics switching bridge. Examples of challenging measurement tasks the CS448 can handle easily are: voltage and charge of gate drives, loss and parasitic stress in power switching, power and spectrum of output signals for EMC compliance, control system signals for gain/phase and stability, etc. The CS448 includes an isolated 65MHz signal generator to provide stimulus signals for frequency response analysis, and eight isolated 100Mb/s logic inputs to simultaneously measure control signals. Two CS448’s can be connected to make an eight channel isolated oscilloscope with coherent sampling.

The CS448’s very low noise design enables accurate measurements of small voltages during large (e.g. 1000V) swings. With input ranges of +/-0.8V and +/-8.0V, custom attenuation probes extend the measurement range up to 1600V. The application software automatically scales all values to compensate for probe attenuation.

The CS448 offers >100dB CMRR at 50MHz, and withstands 1kV working voltage between each channel and ground. The high CMRR and the isolated design allow high-side gate drives to be measured without large unwanted common mode artifacts. Dead time, pulse timing, gate charge characteristics, and parasitics can all be observed.

Sampling at 500MSa/s, all 4 channels are phase aligned with better than +/-140ps skew, so the CS448 can be used for impedance and gain/phase measurement. The signal generator also has >110dB CMRR at 50 MHz, with a working isolation between the output and ground of 800VRMS. The CS448 provides coherent measurements of the channel inputs with the built-in tracking generator. In addition, the CS448 has a 110dB frequency domain dynamic range using its 14-bit ADC’s, which is ideal for EMI, and frequency response analysis.

The CS448’s combination of an optically-isolated, four-channel high dynamic range oscilloscope plus a signal generator is invaluable for measuring power switching values, carrying out tradeoff analyses, and verifying the design and operation of power electronics circuits in machinery or electric vehicles. Connection to a Windows PC for display and operation with the application software provided is via USB or a galvanically or optically isolated Ethernet connection. A built-in Link Port is used for controlling Cleverscope accessory devices such as the CS1070 1A 50MHz power amplifier, or the CS1110 VCE Sat Probe. The CS448 also includes RS232, SPI and I2C ports for controlling user equipment.