Performance characteristics and applications of 5000 series high-speed computer oscilloscopes

The way most digital oscilloscopes achieve their high sample rates is by time-interleaving multiple 8-bit ADCs. Although carefully designed, this interleaved processing can introduce errors such that dynamic performance is always worse than that of a single ADC core.

The new PicoScope 5000 Series oscilloscopes have a significantly different architecture, with multiple high-resolution ADCs applied to input channels at different times and combined in parallel to increase sample rate or resolution.

In time-interleaved mode, the ADC is interleaved to provide a 1GS/s sampling rate at 8-bit resolution. Interleaving reduces the performance of the ADC, but the results produced (60dB SFDR) are still significantly better than a scope with an interleaved 8-bit ADC. This mode also provides a 500MS/s sampling rate at 12-bit resolution (see Figure 1).

In parallel mode, multiple ADCs phase-sample each channel to increase resolution, improve dynamic performance, and reduce noise. Using parallel mode, the resolution is increased to 14 bits per channel (70dB SFDR) at 125MS/s sampling rate. If only 2 channels are required, the resolution can be increased to 15 bits. In single-channel mode, all ADCs are combined to provide 16-bit resolution at a 62.5MS/s sampling rate. The software gives you two choices: select a resolution or keep the oscilloscope in "auto-resolution" mode, using the highest possible resolution for the selected settings.

Front-end design

Pico has more than 20 years of experience in developing high-resolution oscilloscopes, but even so, developing a new analog front end to support oscilloscopes that can switch between different resolutions is a serious challenge. Careful design is required to support high-resolution modes (low noise, low distortion, and flat bandwidth) while maintaining the necessary bandwidth, conversion speed, and impulse response to accommodate faster 8-bit modes.

Portable and powerful

Pico Technology oscilloscopes are compact and lightweight. In 2-channel mode, the 5000 Series oscilloscopes require only USB power. This is very practical for engineers who use it on the go. External power supply is only required when using 3 or 4 channels. The 5000 Series oscilloscopes are suitable for use in many fields, such as design, R&D, testing, education, service and repair.

PicoScope 5000 Series oscilloscopes use multiple high-resolution ADCs to achieve low-noise sampling in interleaved or simultaneous modes with adjustable resolution from 8 to 16 bits.