Using the Interleaved Sampling of the Multi-Channels to Broaden Bandwidth of Embedded Oscilloscope Systems

In this paper, we propose the design and implementation of an embedded oscilloscope system by using the interleaved sampling of multi-channels to broaden the bandwidth. Each channel has an analog-to-digital converter (ADC), data-buffers and I/O interface. We use multi-channel modules to carry out interleaved sampling for obtaining multiple waveforms sampling during an interval. In the design example we used four sets of ADCs, data-buffers and three I/O interface ICs to construct an interleaved sampling by four-channels. We use a fraction of a clock period as the delay time of each channel, and through merging the four sets of sampling waveform data arrive at the measured waveform. Theoretically, the interleaved sampling of four-channel merging should be able to broaden the bandwidth of an embedded oscilloscope system by 400%. If the bandwidth of an oscilloscope is higher, the price is also higher. The cost of an oscilloscope is in proportion to the bandwidth by an exponential relation, not by a linear one. If we use an interleaved sampling design to increase the bandwidth by 100%, we only need to add a set of ADC and data-buffers besides the cost of the basic embedded system. The cost of an oscilloscope can increase at less than an exponential relation with respect to the bandwidth.