Acquisition Crate Design BI Technical Board 26 August 2011 Beam Loss Monitoring Section William Vigano’ 26 August

Acquisition Crate Design Philosophy The design philosophy is the following: Performance Improving System Reliability Protection and Current Limiting Total separation between System Functionality and System Safety Functions Remote Diagnosis Remote control and calibration 26 August

Acquisition Crate Extract by the 3D model of the Acquisition Crate 26 August

BLEDP BLEDP – Cards (Analog Front End) 26 August

BLEDP – Block Diagram Available Resources: 8 Input Analog Interfaces; FPGA local or remote programming; bidirectional optical link; power supplies with protection and diagnosis; temperature and humidity measurement; ID Chip; auxiliary Ethernet link for diagnosis; Auxiliary ADC for Housekeeping Monitor. 26 August

BLEDP High Reliability Dc/Dc Converters Mixed Connector -> 24 pin + 8 Coaxial inserts Shielded Box SFP - Transceiver 26 August

BLEDP - Analog Front End principle The new analog Front End input channel is based on matching two principles: Advanced Current to Frequency converter (it is a fully differential Front End based on Giuseppe Venturini’s proposal for the CERN ASIC) Direct Acquisition (using the fast ADC capability for the current measurement on the input shunt) ACFC DADC Data Output Reset Interface Calibration Interface Input from the Monitor 26 August

ACFC Principle Fully differential Integrator Input switch A status signal selects in which branch of a fully deferential stage the input current is integrated. Two comparators check the deferential output voltage against a threshold, whenever is exceeded, the status signal changes to the complementary value (0 ! 1 or 1 ! 0) and the input current is integrated in the other branch. 26 August

DADC Principle Input 50 ohm resistor split in two: ohmRe-routing on the ADC buffer amplifier 26 August

Analog Front End Block Diagram The two different measurement principles are implemented in a machine able to use the same components but connected in a different way. Some switches in the circuit allow commutation from ACFC to DADC and the opposite. 26 August

ACFC & DADC The input channel circuit is able to measure current input from 10pA to 200mA. The measurement of the current input is performed by two different techniques: 1)Advanced Current to Frequency Converter (ACFC) used in the range 10pA to 30mA 2)Direct ADC acquisition (DADC) used in the range 20.3µA to 200mA The passage between the 2 ranges is managed by the FPGA. When the FPGA measures the maximum ACFC counts, it switches the circuit to the modality DADC. When the value of the DADC returns below a threshold, the FPGA switches the circuit to the ACFC modality. 26 August

Analog Crate Calibration BLEDP Input Channel Input Selector Monitor Input Current Source Optical Transceiver Analog Comparator Threshold Offset Current Internal Flash Memory 48Vdc Backplane Mezzanine Parameters settable remotely:  Analog Comparator Threshold (Digital potentiometer value – channel A)  Offset Current (Digital potentiometer value – channel B)  Measurement Period  Current Source available on the Backplane with precision 2%  Current Source available external with precision 0.1% 26 August All the Channels of all the Cards in the CRATE can be calibrated from remote with the same current reference (Internal or External)

Main Panel Power Supply Presence LEDs Status of Calibration Relays Main Switch Input connector for external Current Source 26 August

CRATE Power Supply The Main Power Supply will be integrated in the CRATE, maintaining the possibility to be replaced in 1 working hour. It generates a common voltage bus of 48 Volts for all the cards in order to limit the current flowing on the backplane, optimizing in the meantime the ripple noise. 26 August

Power Supply Structure Block Diagram Main Power Supply Local creation of all required voltages in the BLEDP Cards 26 August Circuit Breakers

Backplane The Backplane will manage the following functions: Monitor input wiring 48Vdc Power Distribution and protection by Resettable Fuses Internal Current Source Relays Multiplexer for Calibration of all the channels with the same current 26 August

BLECU The BLECU is a Controller Card. It will be implemented in a second stage of the project to improve the functionalities of the Backplane. It will manage the following functions: Detection of the current break for the 48V lines Global CRATE current consumption measurement Remote On/Off of the BLEDP Cards Current Source selection (Internal/External) Current Value selection for the Internal Current Source CRATE Temperature and Humidity measurement (Sensor mounted on the Backplane) CRATE Identifier chip readout (Chip mounted on the Backplane) 26 August

Simulation Models BLEDP Analog Input Interface PSPICE Model Current Source PSPICE Model PSPICE Models were create to simulate several working conditions like worst case, Monte Carlo analysis, extreme performance. Dc/Dc Converter – TI SwitcherPro Model 26 August The BLEDP Analog Input Interface PSPICE model allows to verify and evaluate all the circuit delay errors, input leakage current and signal distortion.

Prototype Verification Current Source BLEDP Analog Input Interface Prototypes have been created to verify the BLEDP Analog Input Interface and the Current Source 26 August

Prototype Results The BLEDP Analog Input Interface Prototype allow to measure the current in the range: 3 pA ÷ 200mA 26 August Better evaluation of performances will be done with the BLEDP PCB (currently in the design and manufacturing phase)

Thank you for your attention 26 August