DRAFTPMTHVBaseERD_ver2.3 PMT HV BASE BOARD ERD
IceCube
PMT HV Base Board
Engineering Requirements Document (ERD)
Version 2.31c (Draft)
Revisions:
VersionDraft #1.0 W. Stroewe
1.1A. Karle
1.2A. KarleJuly 29, 2002
2.0N. KitamuraAugust 15, 2002
2.1aN. KitamuraSeptember 13, 200229 July 2002
2.1bN. KitamuraSeptember 16, 2002
2.1cN. KitamuraSeptember 25, 2002
2.2N. KitamuraOctober 10, 2002
2.2aN. KitamuraOctober 24, 2002
2.2bN. KitamuraOctober 25, 2002
2.2cN. KitamuraNovember 15, 2002
2.2dN. KitamuraNovember 18, 2002
2.2eN. KitamuraNovember 21, 2002
2.2fN. KitamuraDecember 12, 2002
2.2gN. KitamuraDecember 16, 2002
2.2hN. KitamuraJanuary 13, 2003
2.3N. KitamuraMarch 7, 200329 July 2002
Action Items:
Action items are noted in italic in the text. The most important once are:
Fixed first dynode HV fixed for all PMT?
Power requirement
DC and pulsed currents
Discuss differences to J. Przybylski’s requirements page.
Others:
Connectors
Anode signal analog interface
7.) Noise
PRELIMINARYDRAFT
Table of Contents
Table of Contents
List of Figures
List of Tables
1GENERAL
1.1Scope
1.2Purpose
1.3Precedence
1.4Responsibilities
1.5Records
1.6Units
1.7Glossary and Acronyms List
1.8References
2FUNCTIONAL OVERVIEW
3PERFORMANCE REQUIREMENTS
3.1The HV PMT Supply
3.1.1General
3.1.2Dynode Chain Voltage Distribution
3.1.3Damping Resistor Requirements
3.1.4HV Control
3.1.5Anode Current Sourcing Capability
3.1.6Stability
3.1.7Noise
3.2Electrical
3.2.1Power
3.2.2Ground
3.2.3Anode Signal Connection Requirements
3.2.4PMT Mounting Holes Requirements
3.2.5Digital Functionality Requirements
3.3Physical
3.3.1Definition
3.3.2Overall size and shape requirements
3.3.3Component placement
3.3.4Excluded area
3.3.5Minimum trace spacing requirements
3.3.6Manual soldering compatibility
3.4Environmental
3.4.1Temperature Range
3.4.2Pressure Range
3.5Miscellaneous
3.5.1Conformal coating
3.5.2Silkscreen
Appendix 1Design Notes
TABLE OF CONTENTS
List of Figures
Figure 2.1Functional overview of the PMT HV Base board.
Figure 3.1Split ground configuration requirement
Figure 3.2Anode signal coupling transformer signal definition (Illustration purpose only. See text for correct winding requirements).
Figure 3.3Plated-thru PMT mounting hole locations viewed from the top-side of the PMT HV Base circuit board. The numerical labels associated with the holes mark the corresponding PMT pin number whose signal assignments are defined in Table 3.3.
Figure 3.4Solder pad specification
Figure 3.5Ribbon connector signal assignment
Figure 3.7PSL Drawing No. 5549B020. PMT HV Base Board dimensional and component placement requirements. The figure identifies suggested locations for the ribbon cable connector, the coaxial cable attachment, and the clean ground wire attachment. The PCB material thickness is for reference only. (5549020B_e.pdf)
Figure 3.8PSL Drawing No. 5549C021. PMT HV Base Board component envelope definition. (5549021C_e.pdf)
List of Tables
Table 2.1Summary of electrical connections requirements......
Table 3.1Dynode chain voltage distribution (“Dyn” denotes the n-th dynode or Dynode n. “Fn” denotes the n-th focusing electrode.)
Table 3.3PMT Pin Assignment
Table 3.4Power ON/OFF signal assignment
Table 3.6Ribbon connector signal assignment
1GENERAL
1.1
1.2
1.3To be supplied once this document has settled down.
1.4Note on functional requirements:
1.5The standard operating noise level is 500 PE/sec. During lab operationg conditions at room temperature the noise level is typically 5000 Hz, initially significantly higher Therefore, we define a lab operating mode with a noise rate of up to 20kHz. For the operating mode under dark and cold conditions we assume a noise rate of 1000 Hz. The default gain will be 1E7. Gains up to 5E7 shall be supported. The default noise 500 Hz. Noise rates up to 1000 Hz shall be supported for the dark mode. Current requirements are calculated based on the above numbers for contingency in gain added.
1.6Requirements refer to dark mode, unless specified otherwise.
1.7
1.81.11.0ScopeSCOPE
This IceCube Engineering Requirements Document (ERD) specifies the physical, functional and performance requirements for the PMT High Voltage Base circuit board.
22.0GENERAL
1.22.1PurposePurpose.
This requirement documentation shall be applicable to the development, prototyping, testing, and verification of the PMT High-Voltage Base circuit board.
1.32.2Precedence
. In the event of a conflict between the provisions of this document and any prior other IceCube documents above it, the provisions of this document shall govern. Conflicts with other documents are resolved by the Change Control Board.
1.42.3Authority. Approval of this document for initial release and subsequent changes are authorized only by the Change Control BoardResponsibilities
1.4.1Physics/Engineering is responsible for writing and updating these requirements to ensure they are correct, complete and current.
1.4.2Quality Assurance is responsible for ensuring this document and changes to it are properly reviewed, approved and maintained.
1.5Records
Records of initial review, approval and changes (Engineering Change Notices, ECN’s) in design shall be maintained according to the established processes.
1.62.4Units.
Weights and measures in this document are expressed in the MKS International System of Units (SI).
2.11.72.5Glossary and Acronyms List.
ADCAnalog-to-Digital Converter
AWGAmerican Wire Gauge
cmCcentimeter
CMOSComplementary Metal Oxide Semiconductor
CS0Chip-select bit 1
CS1Chip-select bit 0
DACDdigital-to-Aanalog Cconverter
DAQData Acquisition System
DCDdirect Ccurrent
DOMDdigital Ooptical Mmodule
DOMMBDigital Optical Module Main Board
ERDEngineering Requirements Document
GGiga (109)
HVHhigh Vvoltage
HzHhertz
IDInside Diameter
IIDIn-Ice Devices
IDCInsulation Displacement Connector
IPCInstitute for Interconnecting and Packaging Electronic Circuits
kKkilo (103)
kgKkilogram
LEDLight-Emitting Diode
MKSMmeter-kilogram-second
MMmega (106)
mMmeter
mAMilliampere
MOSIMaster-Out-Slave-In
MISOMaster-In-Slave-Out
mVvMmillivolt
mWMmilliwatt
nNnano (10-9)
NtnewtonODOutside Diameter
OMOptical Module
PPeta (1015)
PaPpascal
PCAprinted circuit assembly
PCBPprinted Circuit Board
PEPphoto-electron
pFPico Farad
PMTPphotomultiplier Tube
P/NPart Number
PSLPhysical Sciences Laboratory, University of Wisconsin-Madison
P/V ratioPeak-to-valley ratio
s, secSsecond
SCLKSerial Clock
SISystème International d’Unités
SMBSub-Miniature B
SPESsingle Photoelectron
TTera (1012)
TBDTo Be Determined
TBSTo Be Supplied
ULUnderwriters Laboratory
VVvolt
VDCVolt DC
WWwatt
3
3.11.8References
- IceCube DOM Main Board – PMT HV Base Board Interface Requirements (Document No. 9000-0006)
- DOM Main Board Hardware Requirements (Document No. 9000-0007)
- PSL Drawing No. 5549B020 (PMT HV Base Circuit Board)
- PSL Drawing No. 5549C021 (PMT Envelope)
- IPC-2221 (Generic Standard on Printed Board Design)
42FUNCTIONAL OVERVIEW
in terms ofThe photo-multiplier tube high-voltage base (PMT HV Base) board is a modular PCB component to be integrated into each of the approximately 5000 optical modules (OM), containing a photo-multiplier tube (PMT), that will be deployed in the Antarctic deep-ice (below several kilometers) for scientific research purposes. The PMT referred to in this document is a Hamamatsu Model 7081-02 with a nominal size of 10 inches (25.4 cm) in diameter and a nominal gain of 108.
The PMT HV Base board is required to function continuously without service over the entire twenty-year span of the research project under the deep-ice condition. The operating temperature of the PMT HV Base board is a function of the deployment depth of the Optical Module in the ice, ranging roughly from –20C to –40C, whereas the operating pressure is that of the internal pressure of the OM, approximating the Antarctic ambient pressure of ~0.5 atm. See 3.4Environmental.
The PMT HV Base board has physical andelectrical connections inside the OM with the photo-multiplier tube (PMT) and the digital optical module (DOM) main board (MB), the latter serving as the master controller of the entire OM. Figure 2.1 depicts the functional relationship among the PMT HV Base board, the DOMMB and the PMT. Table 2.1 summarizes the electrical connections between the PMT HV Base Board and the DOM Main Board.
The purpose of the PMT HV Base board is to facilitate the following functions:
- Generate a series of high-voltages for the individual dynodes, focusing electrodes and the anode of the PMT, using the power provided by the DOMMB.
- Transfer the anode signal pulses from the PMT to the DOMMB without distortion through a coaxial cable.
- Respond to the digital control commands issued by the DOMMB for power on/off and for the adjustment of the high voltages.
- Provide a digital reading of the high voltage to the DOMMB upon request.
- Provide digital board identification information to the DOM MB upon request.
The mechanical installation of the PMT HV Base board is accomplished by inserting the PMT lead pins into the plated-thru holes arranged on the PCB and soldering the pins to the annular pad associated with each plated-thru hole; this procedure also establishes the electrical connections between the PMT and the PMT HV Base board.
Detailed functional and performance requirements are specified in the rest of the document.
3.1Function. The PMT HV Base circuit board is a custom-designed commercial product with a low power consumption of less than 300 mW. It will be used to provide the HV for the 10 inch PMT R7081-20 manufactured by Hamamatsu.
3.2Installation. The PMT HV Base circuit board is mounted to the leads at the end of the PMT. The PMT Anode signal cable provides a signal link between the PMT HV Base Circuit Board and the DOM PCB. A separate cable between the PMT HV Base Circuit Board and the DOM PCB provides the DC voltage. The DOM PCB shall transmit control signals and receive monitoring signals from the PMT HV Base. The PMT HV control and monitor signals shall be digital to prevent noise; correspondingly, the interface and PMT design shall demonstrate that no noise is introduced by the operation of the PMT HV base.
Figure 2.13.1Functional overview of the PMT HV Base board.
Table 2.1Summary of electrical connections requirements
Connection method / Explanation / SectionPlated-thru mounting holes / The board is physically mounted to the PMT by soldering the pins to these holes, which also makes electrical connections. / 3.2.4
Coaxial
RG-180B/U or equivalent / Connection between the secondary of the anode signal coupling transformer and the DOM main board. The board shall be delivered with one end of the coaxial cable attached to it. The other end of the coaxial cable requires an SMB type connector. / 3.2.3
IDC Ribbon cable / Digital signals
DC power
Power & digital ground
A male connector is required on board. / 3.2.5.2
0.52 mm2 (20 AWG) stranded wire / “Clean ground” connection.
The board shall provide a wire pad. / 3.2.2.1.E
Page 1 of 27
DRAFTPMTHVBaseERD_ver2.3 PMT HV BASE BOARD ERD
33.3 Function and Performance.PERFORMANCE REQUIREMENTS
4.1
4.23.1The HV PMT Supply
3.1.1General
This subsection specifies electrical requirements applicable to the HV PMT supply portion of the PMT HV Base Board 4.2 .
3.1.1.1Note on requirements alternatives
A set of alternative requirements, replacing the requirements defined in Section 3.1.4, shall be issued at a later date as a supplement to this ERD. The vendor of the PMT HV Base board shall be appropriately notified by IceCube as to whether the present requirements or the said alternative requirements are to be enforced.
3.1.1.23.3.1 HV Generation.
The method of HV generation shall be compatible with all theotherperformance requirements stated in this e rest of the document. In particular, the electrical impedance of the voltage sources for the individual dynodes A Cockroft-Walton type circuit topology may be used, in which case thestclose to. must be sufficiently low in order to meet the anode current sourcing capability (3.1.5).[1]
3.1.1.3Definition
(a)“First dynode voltage” shall refer to the voltage between the cathode and the first dynode of the PMT.
(b)“Anode voltage” shall refer to the voltage between the first dynode and the anode of the PMT.
4.1.6
4.2.13.1.2Dynode Cchain Vvoltage Ddistribution[2]
4.2.1.13.1.2.1Cathode potential
The PMT cathode shall be at ground potential.
4.2.1.23.1.2.2Dynodes
The dynode chain voltage distribution (voltage ratio) shall be (TBD).The voltage across the successive dynode stages shall be according to the values specified in
Table 3.1 in which the values are expressed in terms of a factor to be multiplied by the voltage across Dynode 1 (first dynode) and Dynode 2.
4.2.1.33.1.2.3Focusing electrodes
The voltage for the focusing electrodes, denoted as F1 – F3, shall also be determined by the factor specified in
Table 3.1 multiplied by the voltage across Dynode 1 and Dynode 2.
Note: F1 and Dy1 are at the same potential. F2 and F3 are at the same potential.
3.1.3Damping Resistor Requirements
4.2.1.43.1.3.1
A 100 (5% or better) resistor shall be present between each one of the last dynodes (Dy8, Dy9 and Dy10) and the corresponding high-voltage sources.
3.1.3.2
The said damping resistors shall be installed at locations easily accessible for the IceCube engineers to shunt or replace after the PMT HV Base board has been mounted on the PMT.
Table 3.1Dynode chain voltage distribution (“Dyn” denotes the n-th dynode or Dynode n. “Fn”denotes the n-th focusing electrode.)
Interval / Voltage relative to Dy1 - Dy2Dy2 - Dy3 / 1.25
Dy3 - Dy4 / 0.83
Dy4 - Dy5 / 0.42
Dy5 - Dy6 / 0.25
Dy6 - Dy7 / 0.30
Dy7 - Dy8 / 0.38
Dy8 - Dy9 / 0.55
Dy9 - Dy10 / 0.75
Dy1 - F1 / 0.15
Dy1 - F2 / 0
Dy1 - F3 / 0.15
4.2.2
4.2.3Justification: This depends on the final selection of the PMT model.
4.2.43.1.4HV Control
4.2.4.1Justification: Cockcroft Walton type voltage multipliers provide a power efficient way of HV generation for PMT.
4.2.4.2
3.1.4.1HV controllability requirements
3.1.4.1.AFirst dynode voltage
(a)The PMT HV Base board shall allow the first dynode voltage shallto be set to the factory default value of 700 VDC.a
(b) There shall be a provision for changing the said factory default value after delivery by the IceCube personnel to a value in the range of fixed value in the range of 6400 to 8600 VDC after delivery, using a readily-accessible and reliable method, such as installing or replacingpreferably by installing a resistor of a suitable value.
3.1.4.1.BCathode-to-anode voltage
The cathode-to-anode voltage shall be adjustable at least over the range of 1000 to 2000 VDC (TBD) by means of a means of a suitable digital code written written to thea DAC residing on the PMT HV Base boardby the DOM main board.[3]usually chosen to be 29%, . ais The digitally adjustable voltage ranges are (TBD).
3.1.4.2HV monitoring requirement
There shall be a provision for monitoring the cathode-to-anode voltage as a digital code of an ADC reading transmitted to the DOM main board.[4]
4.2.4.3
3.1.4.3Digital interface
4.2.4.3.A3.1.4.3.ADAC resolution
The DAC used for setting the HV shall have a resolution of 12-bit.
3.1.4.3.BADC resolution
The ADC used for monitoring the HV shall have resolution of 12-bit.
3.1.4.3.CDigital code vs HV[5]
(a)The digital code for setting and monitoring the HV shall be in 12-bit unsigned straight binary with the digital value 000(hex) representing 0 V.
(b)The digital value and the corresponding HV value shall have a linear relationship at least in the voltage range specified in3.1.4.1 with the slope of 0.5 V per bit.
3.1.5Anode Current Ssourcing Ccapability[6]
The HV generator of the PMT HV Base board shall support the following current sourcing capability in the sense that the output voltage does not drop more than 10 V while producing the specified current::
(a)DC anode current of 12 nA at –40 C (deep-ice).
(b)DC anode current of 240 nA at room temperature (laboratory).
(c)Square-pulse anode current of 100 mA lasting for 1 sec.
Square-panode
3.1.6Stability
The drift rate for the voltages supplied to the dynodes and the anode shall be less than 4 V / week during the regular in-ice operation.[7]
3.1.7Noise
The ripple voltage observed at the output of the secondary of the anode signal-coupling transformer shall be no greater than 0.5mVpp when the output is terminated with a 100 resistor.[8]
3.2Electrical
3.2.1Power
4.2.4.43.2.1.1
Voltages between the cathode and the first dynode are to be set separately.
Voltages between the cathode and the first dynode are to be permanently, e.g. by choice of a resistor. These voltages range from 400 to 660 VDC. Voltages between the first dynode and the anode are to be set separately by serial communication to a DAC. These voltages can range from 300 VDC to 1320 VDC. The HV can be turned down or turned off completely by the DOM PCB.
Justification: The PMT gain is controlled by the voltage across the dynode chain (first dynode to anode). The first dynode voltage is frozen to a predetermined value. The first dynode voltage is mainly needed to warrant an adequate P/V ratio. This parameter should not require readjustment.
Status: 20 prototypes are expected in August for tests. A total of 20 PMT are available to perform tests.
Drawbacks: Approach is somewhat unconventional. Some questions are not answered yet. Can the first dynode voltage be uniform for all PMT? Would we need a unique base (resistor setting for first dynode) for every PMT?
Alternate requirement definitions:
Variable control via DAC of the voltage between the first dynode and the anode. Variable control via DAC between the cathode and the first dynode.
Justification: This design allows maximum flexibility. The P/V can be adjusted and readjusted if needed or desired. The PMT gain is controlled separately by the voltage across the dynode chain. The first dynode voltage mainly influences the P/V ratio of the PMT but only to lesser degree the gain. No final decision on the first dynode voltage is needed.
Status: Such a design is has been used on string 18 and on the about 20 DAOM deployed in AMANDA-II.
Variable control between the cathode and the anode (classical design).
Justification: As long as the P/V ratio is within the requirements it doesn’t matter if the P/V ratio changes as a function of HV. This is a conventional mode of operation.
Status: This is probably the simplest design.
Drawbacks: However, if a PMT which is rated for a gain of 1E8 is operated at a gain of 1E7, it is likely that the P/V ratios drop to values that are unnecessary small.
3.3.3HV stability. Any fixed HV setting shall not vary by more than 0.2%/week during regular operation. Any variable HV setting shall not vary by more than 4V/week during regular operation.
Jusitification: The gain-HV relation of the PMT in consideration can be approximated by G = A VB. Therefore a gain stability of dG/G=x requires a voltage stability of dV/V = (B-1)*dG/G. In our case, B is in the range from 8 to 10, depending on the tube. We assume B=10, the worst case. Then a 2% change in gain will arise from a 0.2% change in voltage. Likewise, 3% gain setting ability will be gotten with 0.3% voltage change.
Noise. Maximum ripple induced by the HV generator onto the anode signal shall not exceed 0.25 mVp-p.when terminated with 100 Ohm.
Justification: Difficult.
0.25 mV will be not easy to measure.
Alternate requirement:
Noise shall be small enough that the P/V ratio of the PMT is not reduced by more than 5%, when operated at a gain of 1E7.
DAC resolution. The DAC resolution shall be 12 bit.
Justification: A resolution and 2% of the gain appears adequate. In order to avoid fluctuations due to quantization jumps it the DAC resolut6ion should be small compared to the required stability.
An 12 bit resolution meets this requirement.
Monitoring voltage: A monitoring signal of the actual HV shall be provided using a 12 bit ADC to readout the actual HV.
Justification: It is useful to read the exact state of the HV. The ADC resolution should meet the DAC resolution.
Resolution. The maximum linear output of the PMT converts to a nominal digital value of 7168.