Abstract
A wide range current digitizer card is needed for the acquisition module of the beam loss monitoring systems in the CERN Injector Complex. The fully differential frequency converter allows measuring positive and negative input currents with a resolution of 31 nA in an integration window of 2 μs. Increasing the integration window, the dynamic range covers 21010 were the upper part of the range is converted by measuring directly the voltage drop on a resistor. The key elements of this design are the fully differential integrator and the switches operated by an FPGA. The circuit is designed to avoid any dead time in the acquisition and reliability and failsafe operational considerations are main design goals. The circuit will be discussed in detail and lab and field measurements will be shown.
Highlights
The DADC activation and de-activation thresholds can be set by the FPGA
The required time to switch between FDFC and DADC is less than 100 ns so in the minimum acquisition period of 2 μs it is possible to follow the input signal switching adequately
When the FPGA observes a signal above the DADC activation threshold, it switches the circuit to the DADC acquisition
Summary
The required time to switch between FDFC and DADC is less than 100 ns so in the minimum acquisition period of 2 μs it is possible to follow the input signal switching adequately. When the FPGA observes a signal above the DADC activation threshold, it switches the circuit to the DADC acquisition. When the value of the DADC returns a signal below the de-activation threshold, the FPGA switches the circuit to the FDFC acquisition.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
