10GSPS High-Resolution Time Domain Digitizer

Jun 18 2024

Oscilloscopes and digitizers are common test and measurement instruments found in scientific research and electrical engineering laboratories to measure and display waveform characteristics like voltage of electrical signals over time. They are used by engineers for debugging and signal analysis of electronic circuits, high speed interfaces, and buses; and by scientists for digitizing signals from various sensors. Digitizers are also key modules for scientific instrumentation applications such as Time-of-Flight mass spectrometry and distributed fiber optic sensing.

As speeds and bandwidths of wired technologies like PCIe, USB, optical, and high speed ethernet evolve, the complexity and demands of digitizers and oscilloscopes are constantly increasing. In scientific instruments, high-speed means better measurement resolution, and in the case of time-of-flight mass spectrometry smaller system footprint as well. Today’s digitizers attain speeds well into the GHz range, and at the same time they need to maintain true DC measurement capability which makes the digitizer design an extremely challenging engineering problem.

To address this challenge, ADI is developing a 12 bit, DC Coupled, 10GSPS digitizer reference design, supporting 5GHz of bandwidth with low jitter and high dynamic range. It supports both 50 ohm and 1Mohm input impedances and includes both high speed and precision DC coupled signal paths. The high speed signal chain includes AD9213 which is a 12 bit, 10GSPS ADC and is driven by ADL5580 which is a 10GHz driver amplifier. The precision path uses ADI’s recently released 20 bit SAR ADC, AD4080 with a sample rate of 40MSPS and sub-1Hz 1/f noise corner.

Here, we’re demonstrating the benefit of the DC-coupled signal chain for maximizing the dynamic range and SNR of a pulse signal, similar to that which would be captured by a time-of-flight mass spectrometry instrument. By adjusting the DC offset at the input to our high-speed ADC driver, we’re able to digitize signals with various DC offsets using the full dynamic range of the ADC. We shift the waveform within the ADC window and simultaneously reduce the attenuation applied to the signal, enabling an increase in dynamic range by a factor of two and hence improved SNR.

10GSPS High-Resolution Time Domain Digitizer

Jun 18 2024
Oscilloscopes and digitizers are common test and measurement instruments found in scientific research and electrical engineering laboratories to measure and display waveform characteristics like voltage of electrical signals over time. They are used by engineers for debugging and signal analysis of electronic circuits, high speed interfaces, and buses; and by scientists for digitizing signals from various sensors. Digitizers are also key modules for scientific instrumentation applications such as Time-of-Flight mass spectrometry and distributed fiber optic sensing.

As speeds and bandwidths of wired technologies like PCIe, USB, optical, and high speed ethernet evolve, the complexity and demands of digitizers and oscilloscopes are constantly increasing. In scientific instruments, high-speed means better measurement resolution, and in the case of time-of-flight mass spectrometry smaller system footprint as well. Today’s digitizers attain speeds well into the GHz range, and at the same time they need to maintain true DC measurement capability which makes the digitizer design an extremely challenging engineering problem.

To address this challenge, ADI is developing a 12 bit, DC Coupled, 10GSPS digitizer reference design, supporting 5GHz of bandwidth with low jitter and high dynamic range. It supports both 50 ohm and 1Mohm input impedances and includes both high speed and precision DC coupled signal paths. The high speed signal chain includes AD9213 which is a 12 bit, 10GSPS ADC and is driven by ADL5580 which is a 10GHz driver amplifier. The precision path uses ADI’s recently released 20 bit SAR ADC, AD4080 with a sample rate of 40MSPS and sub-1Hz 1/f noise corner.

Here, we’re demonstrating the benefit of the DC-coupled signal chain for maximizing the dynamic range and SNR of a pulse signal, similar to that which would be captured by a time-of-flight mass spectrometry instrument. By adjusting the DC offset at the input to our high-speed ADC driver, we’re able to digitize signals with various DC offsets using the full dynamic range of the ADC. We shift the waveform within the ADC window and simultaneously reduce the attenuation applied to the signal, enabling an increase in dynamic range by a factor of two and hence improved SNR.