Electronics for PS and LHC

transformersGrzegorz KasprowiczGrzegorz Kasprowicz

Supervisor: David BelohradSupervisor: David Belohrad

AB-BDI-PIAB-BDI-PITechnical student reportTechnical student report

Why new PS transformers Why new PS transformers electronics is needed?electronics is needed?

Current calibration procedure doesn't Current calibration procedure doesn't allow full scale calibration on the low allow full scale calibration on the low sensitivity range -> source of errorsensitivity range -> source of error

It does not support remote It does not support remote adjustments (required by LHC)adjustments (required by LHC)

Calibrators work only in manual Calibrators work only in manual mode – require operator in place mode – require operator in place they are installed during calibration they are installed during calibration procedureprocedure

PS integrators – following PS integrators – following conceptions were built and testedconceptions were built and tested

Analogue integrator solution based Analogue integrator solution based on diode switches and high speed on diode switches and high speed OPAMPsOPAMPs

Analogue integrator solution based Analogue integrator solution based on IVC102U integrated chipon IVC102U integrated chip

Digital solution based on High Speed Digital solution based on High Speed ADCsADCs

Analogue integrators prototype Analogue integrators prototype boardboard

Analogue integrator 1 Analogue integrator 1

This version was implemented using This version was implemented using diode switches driven by current diode switches driven by current switches.switches.

The linearization block that The linearization block that compensates diode switches compensates diode switches nonlinearities was usednonlinearities was used

High speed voltage feedback opamps High speed voltage feedback opamps were usedwere used

Linearity results meet PS needsLinearity results meet PS needs

Integrator 1 linearity resultsIntegrator 1 linearity resultserror vs input current

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

-6 -5.5 -5 -4.5 -4 -3.5 -3 -2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 3 3.5 4

current [mA]

erro

r[%

]

Series1

Analogue integrator 2Analogue integrator 2

Based on IVC102U chip, which Based on IVC102U chip, which integrates operational amplifier, integrates operational amplifier, switches and capacitors.switches and capacitors.

Too slow for PS application – Too slow for PS application – minimum integration time is ~30us minimum integration time is ~30us while 5us is needed – it saturates while 5us is needed – it saturates output when clocked too fast.output when clocked too fast.

Digital integratorDigital integrator

Existing project PCBs (CCD camera) were Existing project PCBs (CCD camera) were used. It consists of: FPGA, 8051 used. It consists of: FPGA, 8051 microcontroller with USB 2.0 interface, microcontroller with USB 2.0 interface, SDRAM memory, power supply, 2x 12bit SDRAM memory, power supply, 2x 12bit 210MS/s ADC, configuration and program 210MS/s ADC, configuration and program EEPROM, input amplifiers.EEPROM, input amplifiers.

The input signal is sampled and integral The input signal is sampled and integral over specified period is calculated digitally over specified period is calculated digitally in FPGA. Then the result is stored in RAM in FPGA. Then the result is stored in RAM and transferred to PC via USBand transferred to PC via USB

Digital integrator prototype boardDigital integrator prototype board- existing project was used- existing project was used

2x ADC12bits

210MHz

FPGA

USB+ 8051

Program EEPROM

USB Connector

Digital integrator – linearity Digital integrator – linearity results results

linearity error vs input curent

-0.5

-0.4

-0.3

-0.2

-0.1

0

0.1

0.2

Input current [uA]

Err

or

[%]

Digital IntegratorDigital Integrator

Linearity measured meets PS Linearity measured meets PS requirements, but there is expected requirements, but there is expected further improvement caused by further improvement caused by proper clocking and noise.proper clocking and noise.

This version was chosen to This version was chosen to realization as final prototype due to realization as final prototype due to it’s simplicity, reliability and it’s simplicity, reliability and measurement parameters.measurement parameters.

Digital integrator - advantagesDigital integrator - advantages

No precision analog components No precision analog components required, only input amplifier, Low required, only input amplifier, Low Pass Filter and ADC driverPass Filter and ADC driver

Linearity guaranteed by ADCLinearity guaranteed by ADC Good thermal stabilityGood thermal stability Simplicity – fewer component count Simplicity – fewer component count

that improves reliability that improves reliability Thanks to FPGA, function of device Thanks to FPGA, function of device

can be changed remotelycan be changed remotely

Linearity measurement test benchLinearity measurement test bench

Integrators 1 and 2 were connected Integrators 1 and 2 were connected to digital integrator board to simplify to digital integrator board to simplify measurementsmeasurements

Simple control application working Simple control application working under Windows was written to allow under Windows was written to allow easy control of integrators easy control of integrators parameters and results acquisitionparameters and results acquisition

TestbenchTestbench

Control applicationControl application

PS Calibrators – following PS Calibrators – following conceptions were built and testedconceptions were built and tested

Charge calibrator with 200V DC/DC Charge calibrator with 200V DC/DC converterconverter

Current calibrator – switched current Current calibrator – switched current source 4A/200Vsource 4A/200V

PS charge calibratorPS charge calibrator How does it work?How does it work? DisadvantagesDisadvantages Newer version of existing calibrator – Newer version of existing calibrator –

instead of mechanical switch, instead of mechanical switch, MOSFET was used. This allows MOSFET was used. This allows remote operationremote operation

Integrated 12V/300V DC/DC Integrated 12V/300V DC/DC converter that simplifies supplyconverter that simplifies supply

Charge calibrator prototypeCharge calibrator prototype

PS current calibratorPS current calibrator

How does it work?How does it work? DisadvantagesDisadvantages There was built adjustable pulse current There was built adjustable pulse current

source – 0..4A / 50 Ohmsource – 0..4A / 50 Ohm Switch on/off time <100nsSwitch on/off time <100ns Problems with thermal stability, linearity Problems with thermal stability, linearity

and transients occurred – improved and transients occurred – improved solution with compensation was developedsolution with compensation was developed

Prototype was built using discrete Prototype was built using discrete components (transistors only), improved components (transistors only), improved version uses CFA and MOS driversversion uses CFA and MOS drivers

PS current calibratorPS current calibrator

VME Intensity measurement system VME Intensity measurement system for PSfor PS

Compact single board solution based on VME busCompact single board solution based on VME bus Integrated current/charge calibratorIntegrated current/charge calibrator Integrated HV DC/DC converterIntegrated HV DC/DC converter Based on FPGA technology ensures high flexibilityBased on FPGA technology ensures high flexibility Two high speed ADCs working in parallelTwo high speed ADCs working in parallel System can be used for another data acquisition applicationsSystem can be used for another data acquisition applications All functions and adjustments controlled remotely:All functions and adjustments controlled remotely: - Integration delay, gate time- Integration delay, gate time - calibration delay, pulse width, gate time & delay - calibration delay, pulse width, gate time & delay - offset compensation gate& delay, analogue compensation- offset compensation gate& delay, analogue compensation - calibrators voltage and current- calibrators voltage and current - ….- ….

VME board block schematicVME board block schematic

FPGABUFFERS

ADC 12bit210Ms/s

ADC 12bit210Ms/s

Input Filter And

AttenuatorVME

IN

Power Supply1.5V2.5V3.3V5V-5V

programmableDC/DC

12V/200V converter

Current calibrator – Programmable pulse current

Source – 0..4A,max 200V

Charge calibratorSwitched capacitor

OUT I

OUT Q

VME integrator parametersVME integrator parameters VME 32bit interfaceVME 32bit interface FPGA 6k Logic ElementsFPGA 6k Logic Elements 2xADC 12 bit,210Ms/s with LVDS2xADC 12 bit,210Ms/s with LVDS All VME signals are bufferedAll VME signals are buffered HV DC/DC converter 0..200V programmable HV DC/DC converter 0..200V programmable

range with output voltage monitorrange with output voltage monitor Pulse current source 0..4A programmable Pulse current source 0..4A programmable

rangerange 10.5 ENOB with 50 Ohm input short10.5 ENOB with 50 Ohm input short Linearity better than 0.2%Linearity better than 0.2% Offset compensation (analog and digital)Offset compensation (analog and digital)

VME integrator - prototypeVME integrator - prototype

FPGA

Bus buffers

LPF2x ADC12bit,210MS

Supply regulators

DC/DCconverter

Calibrators

VME board – final versionVME board – final version

VME measurement system statusVME measurement system status

The new board is assembled and The new board is assembled and soon will be ready for testssoon will be ready for tests

The single test software running on The single test software running on VME controller is writtenVME controller is written

The software group (M.Ludwig, The software group (M.Ludwig, J.J.Gras) is working on driversJ.J.Gras) is working on drivers

VME board – final versionVME board – final version Ready-made PCB shielding usedReady-made PCB shielding used Compensated current calibratorCompensated current calibrator Current feedback controller in DC/DC Current feedback controller in DC/DC

converterconverter Test outputs on the front panelTest outputs on the front panel Status LEDs on the front panelStatus LEDs on the front panel Polymer fuses addedPolymer fuses added Board address selection switchBoard address selection switch Fixed minor bugsFixed minor bugs

Fast integrator for LHCFast integrator for LHC Existing integrated (LHC-2002) Existing integrated (LHC-2002)

requires using 2 or more channels to requires using 2 or more channels to achieve 30dB of dynamic range. The achieve 30dB of dynamic range. The improvement of dynamic range gives improvement of dynamic range gives the possibility to use one the possibility to use one measurement range onlymeasurement range only

Low input voltage rangeLow input voltage range Too high input voltage causes chip Too high input voltage causes chip

damagedamage There is under development discrete There is under development discrete

solutionsolution

Fast integrator for LHC – version 1Fast integrator for LHC – version 1

Based on diode switches driven by Based on diode switches driven by transformerstransformers

2 versions of diode drivers built and tested 2 versions of diode drivers built and tested (integrated and discrete one)(integrated and discrete one)

High speed VFA and CFA tested – problems High speed VFA and CFA tested – problems with stability occurredwith stability occurred

Discrete version of CFA developed – Discrete version of CFA developed – problem with output range and power problem with output range and power dissipation of used transistorsdissipation of used transistors

Problem with too high reset timeProblem with too high reset time

Fast integrator for LHC – version 1Fast integrator for LHC – version 1

Fast integrator for LHC – version 2Fast integrator for LHC – version 2

Solved problem with power limitation Solved problem with power limitation of transistors and output voltage of transistors and output voltage rangerange

Still too high reset time (ECL logic Still too high reset time (ECL logic used)used)

Diodes replaced by MOSFETDiodes replaced by MOSFET SRD solves problems with reset time SRD solves problems with reset time

– still under development– still under development

Fast integrator for LHC – Fast integrator for LHC – version 2 - block schematicversion 2 - block schematic

ECL timing

Currentfollower

IN OUT

Pulse trafo

CLK

Fast integrator for LHC – version 2Fast integrator for LHC – version 2

Fast integrator for LHC – version 3Fast integrator for LHC – version 3

LHC integrator testbenchLHC integrator testbench

Based on Cyclone FPGA Based on Cyclone FPGA Development KITDevelopment KIT

Small mezzanine module was Small mezzanine module was developeddeveloped

14bit, 60MS ADC + drivers 14bit, 60MS ADC + drivers It was used to measure integrator’s It was used to measure integrator’s

linearitylinearity

LHC integrator testbenchLHC integrator testbench

LHC integrator linerityLHC integrator linerityintegrator error [%] vs input voltage

-3

-2.5

-2

-1.5

-1

-0.5

0

0.5

0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

input voltage

cou

nt

Series1

Generator amplitude error [%] vs output voltage

-2.5

-2

-1.5

-1

-0.5

0

0.5

1 2 3 4 5 6 7 8 9 10

output voltage

cou

nt

Series1

The following projects are currently The following projects are currently under developmentunder development

VME Intensity measurement system VME Intensity measurement system for PS for PS

Fast integrator for LHC (alternative Fast integrator for LHC (alternative for existing integrated solution)for existing integrated solution)