Evaluation and Test of VA-TAamplifiers. Integrated Detector and Electronics AS IDE AS

Transcription

1 VA-DAQ VA-TA EVALUATION Evaluation and Test of VA-TAamplifiers Integrated Detector and Electronics AS IDE AS

2 1. TABLE OF CONTENTS 1. TABLE OF CONTENTS INTRODUCTION INSTALLATION OF THE VA-DAQ VA-TA-EVALUATION PROGRAM.5 4. HOW TO START THE VA-DAQ VA-TA-EVALUATION SYSTEM (QUICK START) VA-DAQ MAIN MENU...7 Operation: GENERAL SETUP...9 INITIALIZE AND CALIBRATE...10 Operation:...10 VA-DAQ SETUP...12 Operation...12 CALIBRATE VA CURRENT Operation...13 READ DEFINITION FILE...14 Operation...14 FORCE BIAS & SUPPLY...15 Operation...15 CHECK BIAS & SUPPLY Operation...16 ADJUST VA BIASES Operation...17 ADJUST VA SUPPLIES Operation...18 SWAP CHIP/BOARD...18 Operation...18 SHAPE OPTIMIZATION Operation...19 PEAKING SIGNAL/TIME VERSUS BIAS VOLTAGE Operation...20 NOISE AND GAIN AS FUNCTION OF BIAS...21 Operation...21 WRITE DEFINITION FILE Operation VA-EVALUATION...23 OSCILLOSCOPE, FINE AND COARSE RESOLUTION...23 Operation...23 Operation...24 PEDESTALS AND NOISE...25 Operation

3 GAINS AND PEDESTALS...26 Operation...26 PEAKING TIME VERSUS INPUT CHARGE...27 Operation...27 SIGNAL HEIGHT AS A FUNCTION OF INPUT CHARGE...28 Operation...28 SETUP INPUT CHARGE...29 Operation...29 PEAKS...30 Operation: TA-EVALUATION...31 TA VOLTAGE SCAN...31 Operation:...31 TA CHARGE SCAN...32 Operation:...32 SET THRESHOLD...33 Operation:...33 SINGLE CHANNEL (TA-TRIGGERS AS FUNCTION OF INPUT CHARGE)...34 Operation: DETECTOR READOUT...35 SINGLE CHANNEL READOUT OF RAW DATA...35 Operation...35 FULL READOUT OF RAW DATA...36 Operation...36 RAW DATA FILE FORMAT PRESENTATION...38 NICE-PLOT...38 Operation HOW TO CONNECT A DETECTOR TO THE VA-DAQ VA-TA- EVALUATION SYSTEM...39 INTRODUCTION...39 REPLACEMENT OF VA ADAPTER BOARD TO VA-TA ADAPTER BOARD:...39 CONNECTING A DETECTOR TO THE VA-DAQ VA-TA- EVALUATION SYSTEM...39 DETECTOR BIAS SUPPLY...43 EXTERNAL TRIGGERING PIN ASSIGNMENT LIST FOR THE FRONT END INTERFACE...45 INTRODUCTION...45 PIN ASSIGNMENT LIST FOR THE STANDARD-VA ADAPTER BOARD...46 PIN ASSIGNMENT LIST FOR THE VA/TA ADAPTER BOARD

4 2. INTRODUCTION The VA-DAQ VA-TA-evaluation program 1 is a sophisticated test program made for evaluating the VA-amplifier. The VA-DAQ Evaluation program gives the user a wide variety of options for testing and monitoring the VA-TA-amplifier. This software lets the user explore these possibilities within a user-friendly environment. From a set of various tools, you can make many new and exciting tests. You can change parameters and watch immediately the impact on the VA-TA-amplifier. With the discoveries from these tests you can apply the VA-TA-amplifier for your own application with confidence for perfect performance. The program is written for the popular operating system Windows 95. The program s user friendliness let the user generate plots, figures and data files from a several different tests with minimal interaction. The user can therefore investigate the performance and feasibility in greater detail than any other program available. 1 The software is delivered with many different options, apply the chapters that meets your software. Don t get confused with the naming VA - vs. VA -TA- The operation with installation etc are the same. 4

5 3. INSTALLATION OF THE VA-DAQ VA-TA-EVALUATION PROGRAM The VA-DAQ VA-TA-evaluation program is a sophisticated software program made to meet the need to test and evaluate the advanced VA-TA-amplifiers. Before installing the VA-DAQ VA-TA-evaluation program, there are some minor requirements that have to be met. Please check if the computer you would like to use meets the following requirements. The VA-DAQ VA-TA-evaluation system uses the parallel port for communication. It is advantageous that the computer is connected to a network with a printer attached if one want to make hardcopies of figures or data. The software is written for the Windows 95 operating system. The screen resolution must be 1024 X 768 X 256 or similar. 32 Mbytes RAM Mbytes free disk space. 486 or better microprocessor. When installing the software, insert the CD into the drive and run setup.exe. To ensure correct operation, please locate the software in the C:\VA-DAQ directory. The extra disk includes a *.DEF file(s) and a *.INI file. Please copy these files into the selected directory (C:\VA-DAQ). After completion of the installation you will see the three 2 main files in the C:\VA- DAQ directory. The files are: VA-DAQ.EXE. The VA-DAQ VA-TA-Evaluation program you execute. *.DEF. A definition file with the correct setting for the VA-/VA-TA- amplifier hybrid. This is the default file delivered with the system. *.INI. An initialization file that has to be applied to the VA-DAQ system when starting the VA-DAQ VA-TA-evaluation software. The program starts when running the VA-DAQ icon from the program group called VA-DAQ VA-TA-evaluation. 2 Note: You will have one *.ini file for your VA -DAQ system and the same amount of *.def file as you have different hybrids, that is, different types of VA -TA-amplifiers. 5

6 4. HOW TO START THE VA-DAQ VA-TA-EVALUATION SYSTEM (QUICK START) This How to operate the VA-DAQ VA-TA-evaluation system section is a quick introduction for those who don t read manuals bigger than 1 page. Hardware and Software installation 1. Connect all cables, except the hybrid. Connect the communication cable between the printer port on the PC and the VA-DAQ. Connector is located in the back of the VA-DAQ. The cable from the power supply and the VA-DAQ. See own paper for power supply values. The connector is located in the back of the VA-DAQ. 2. Install the VA-DAQ system. Select all default settings. 3. Start the VA-DAQ VA-TA-evaluation program. Running the VA-DAQ 1. Select Initialize & Calibrate. The first item in the selector list for the VA-DAQ VA-TA-evaluation software. 2. Select VA-DAQ Setup. The second item in the selector list for the VA-DAQ VA-TA-evaluation software. 3. Select the first item for the VA-DAQ setup. It is called Calibrate VA Current. Do as you are told. After this point you should connect the hybrid to the system. 4. Select the next item, that is Read definition file 5. Finally, select Force bias & supply. Now you should be up and running. Go back to the main menu and try Channel Oscilloscope. Enjoy! 6

7 5. VA-DAQ MAIN MENU Figure 1. Main window for the VA-DAQ Evaluation and Test of VA-TA Amplifiers. Operation: The VA-DAQ VA-TA-evaluation software is menu driven. The different options are all available on the front panel for easy access. You can select the feature you want to use with a simple click with the pointing device. When selecting the appropriate menu item, the selected windows will pop-up. These tools are described in greater detail in this manual. The main window will also keep a log for unprocessed triggers since initialization. If you have received unprocessed triggers, you should press the button Clear triggers. After you have returned to the main menu, please select the blank field above the first item. This should be done to ensure proper operation of the system. In the lower part of the main window there are several monitors for the current and voltage consumption. This monitoring utility has also a built in function as a fuse if the current limit goes beyond the limit. If that happens, you will get a red light for the current limit. Press the clear button to reset the current limit. 7

8 Table 1. Overview for the main menu items Type Function name Function description VA/TA Initialize & Calibrate: Initialize the VA -DAQ VA -TA-evaluation hardware VA/TA VA-DAQ Setup: Setup for the hybrid and bias settings for the VA -amplifier. VA/TA SWAP VA Chip/Board: Utility used when swapping hybrid or adapter board. VA Channel Oscilloscope: Oscilloscope to investigate the signal. VA Pedestals & Noise: Utility to investigate pedestals and noise. VA Gains & Pedestals: Utility to investigate gains and pedestals. VA Peaking Time: Utility to investigate the peaking time. VA Peaks: Utility to investigate the peaks. TA TA Voltage Scan Utility to do voltage scan. TA TA Charge Scan Utility to do charge scan. VA-TA Single Channel Readout Utility for reading out 1 channel. Note; Detector needed. VA-TA Full Readout Utility for reading out all channels. Note; Detector needed. VA/TA Niceplot: Utility to generate a presentable plot. 8

9 6. GENERAL SETUP Select Initialize & Calibrate. The first item in the selector list for the VA-DAQ VA-TA-evaluation software. You will be asked to select the va-daq.ini file for your system. Select this file. The system will be calibrated. Select VA-DAQ Setup. The second item in the selector list for the VA-DAQ VA- TA-evaluation software. Select the first item for the VA-DAQ setup. It is called Calibrate VA Current. This function will calibrate the VA current. Follow the instructions. After this function the hybrid/chip is now connected to the VA-DAQ Evaluation system. Select the next item, that is Read definition file. You will specify the definition file for your hybrid. Make sure that everything goes OK. Finally, select Force bias & supply. After this little exercise you should be able to operate the VA-DAQ evaluation software and all its exciting tools with success. 9

10 Initialize and Calibrate Figure 2. The Initialization and calibration of VA-DAQ window. Note: When you enter this menu for the first time, you have to find the location of the initialization file. However, next time, the system will suggest the previously used file. Operation: When starting the VA-DAQ VA-TA-evaluation Program you should select the Initialize & Calibrate menu. When starting the VA-DAQ system for the first time, the system needs to be calibrated and adjusted for proper use. This operation will go through the calibration test and read the different settings and parameters needed for successful use. Each VA-DAQ system has it s own va-daq.ini file. If the initialization and calibration procedures are correct, the test labels changes from red to green color. If not correct, the label stays red 3. The first item checked is the digital part of the system. This item has to work! If the other labels are not changing color, check the power supply. 3 It has been seen on some computers that the colors are not red/green. Make sure that the diodes are changing even if the colors are not red/green. 10

11 Figure 3. After completing the initialization and calibration procedure, all the test labels should turn green. The Non-received ADC triggers should display a 0. Make sure that this number is always 0 when starting the system. After this operation the VA-DAQ system s main unit is adjusted and calibrated. 11

12 VA-DAQ Setup Figure 4. VA-DAQ Setup window. Operation The VA-DAQ system and the VA-amplifier need extensive information to be able to run properly. The VA-DAQ setup menu includes as numerous sets of powerful tools that let you adjust these settings and parameters. You can adjust settings for the VA- DAQ system as well as for the VA-amplifier. The menu includes 10 different tools that allow you to tune the system. They are: 12

13 Table 2. The table shows the different utilities for the setup menu. Selector button Description of button Calibrate VA Current Calibrate the current for the VA-DAQ system. Read definition file Read the definition file for your selected hybrid/vaamplifier. Force bias & supply Forces the selected bias and supply values to the system with everything connected. Check bias & supply Checking and controlling the bias and supply values. Adjust VA biases Menu for controlling and adjustments of biases. Adjust VA supplies Menu for adjustments of VDD and VSS supplies. Swap chip/board Tool that let holds the signal on hold when swapping chips/boards. Shape optimization Tools for fine tuning of parameters. Write definition file Utility to write your own definition file. Setup biasing Menu for adjusting biases. Calibrate VA Current. Figure 5. Calibrate VA-supplies current. Operation When entering this option, you will be asked to disconnect the VA-amplifier or hybrid. If your hybrid is not connected, continue. If you have connected your hybrid with the VA-amplifier, please disconnect it, before you continue. After pressing the OK button, you will be asked to connect the hybrid again. At this stage, the connector for the VA-amplifier of board should be connected to the VA-DAQ VA-TAevaluation system. Make sure that you connect the cable in right direction. FYI After this operation the VA-DAQ VA-TA-evaluation program has registered the current consumption by the VA-DAQ VA-TA-evaluation main unit. 13

14 Read definition file Figure 6. Menu window for Read definition file for testing with display for attenuation settings. Operation When entering the Read definition file button, you will be asked to select the definition file for your system. The file is called *.def. When you enter this command later the previously selected file will be suggested. If this is the wanted file, simply press open. If not, select the appropriate file and continue. When reading the definition file the VA-DAQ VA-TA-evaluation system will go through several tests to see if every parameter is adjusted to their right level. The six small symbols located at the lower part of the figure shows the setting for the attenuation. The row with the labels Current setting is the setting your system has right now. The row with the labels Should be is the setting your definition file expects. If there is a discrepancies between these check marks the light will be red and there will not be a one to one match between the current setting and the should be setting as seen in the figure above. The six small symbols are a simplified figure of the jumpers you can find in the back of the VA-DAQ VA-TA-evaluation main unit. 14

15 FYI This software is written for the 1.2 version of the main unit with easy accessible jumpers. This option will in same manner for the older version of the main unit as well. The jumpers are not as easy accessible as for the 1.2 version. In the earlier versions the jumpers can be found inside the unit. Force bias & supply. Figure 7. Force bias & supply. If the test does not pass, you will see a remark in the comment window. Operation The program goes through the VA chip and changes the setting to the given default setting. During the operation the program will display a window telling the user that the program is in progress. Upon completion the window will be substituted with another window giving the appropriate comments. The OK-button will be enabled after completion. Activating the OK-button will take the user back to the main menu 15

16 Check bias & supply. Figure 8. Menu for checking the VA supplies and bias settings. Operation The module is checking bias and supply. The program shows first the progress. Afterwards the results are displayed in the comment window. If there are discrepancies, that is, if there are errors with the biases and the voltages, the light will turn red. Please check the parameter-file and check the default settings. 16

17 Adjust VA biases. Figure 9. Menu for monitoring and adjustments of VA biases. Operation This window shows you the different bias values. In addition to reveal the values, you can also enter your own values, if needed. Select Apply default to see the default values. Are these values OK, press Accept biases, however, are the default values incorrect, then you can adjust the values. Press Accept, and then Return to go back to the main menu. Note; some of the biases need negative voltage, in those cases you are not allowed to enter positive values, and vice versa. Please check the manual for the given VA-amplifier for suggested values. 17

18 Adjust VA supplies. Figure 10. Menu for adjustments of VA supplies. Operation The wanted supply voltage can be specified for the VA/TA hybrid. The voltage can be written into the dialog boxes, or the user can use the arrows to select the voltage. The default option can also be used. Press the Apply default button, and press Accept supply. The Accept supply button will take you back to the main menu. Swap chip/board. Figure 11. Swap VA chip or board. Operation This option lets you change the VA- chip/hybrid or adapter board. The software will put the signal flow on hold, turn off the supply voltage and amplifier biases, while you are doing the swapping. After completing the swap, press the OK-button, and the 18

19 program will take you back to the main menu. The chip biasing and settings are not lost when the VA hybrid is changed using this option. FYI When using the swap VA chip or board option you should be able to hear a click from the relay. Shape optimization. Figure 12. Shape optimization. Operation This utility let you select two useful tools for adjusting bias parameters. Table 3. Parameter used for optimization of bias scans. Selector button Description of button Peaking vs. bias Peaking signal/time vs. bias voltage. Gain/noise vs. bias Noise and gain as a function of bias. 19

20 Peaking signal/time versus bias voltage. Figure 13. Peaking signal/time vs. bias voltage. Operation When using this menu, these are many details that have to be taken into consideration before starting. You have to select the wanted bias. There are some biases that are more critical than others, make sure that you are confident with these biases. Also make sure that you understand the impact of this test for these biases. You have to specify start and end voltage. The size for the calibration step has to be entered. 20

21 Noise and gain as function of bias Figure 14. Noise and gain as function of bias. Operation The Noise and gain as function of bias window is another useful utility. You can easily the impact on the noise when changing the bias voltage. Please select the bias you prefer to scan. Select the start and end voltage. In addition you should set the hold delay. 21

22 Write definition file. Figure 15. Write definition file and inspection window. Operation If you want to make a new definition file, you should enter this menu. There are several reasons why one want to have numerous *.def files. To mention a few. 1. Check the different settings at a later stage. 2. Compare two or more settings to see the impact on the VA-amplifier. You can inspect the files before you write the data to file. The file is written as a plain *.txt file. It should therefore be possible to open the file in any text editor for display. 22

23 7. VA-EVALUATION Low noise, low power high dynamic range charge sensitive preamplifiershaper circuit, with simultaneous sample and hold, multiplexed analog readout and calibration facilities. Oscilloscope, Fine and Coarse Resolution Figure 16. Oscilloscope, coarse resolution. You can switch between the two different modes by changing the setting for the resolution. See upper left corner of the screen dump. Operation This oscilloscope lets you display the signal from the VA-amplifier. You can either select the FINE resolution or the COARSE resolution. This is done with a simple keystroke. The print-button makes a printout of the screen. This option requires that your computer is connected to a network. It will use the default printer for you system. The return-button takes you back to the main menu. In addition the user can apply some more advanced functions. You can adjust individual bias values to investigate the impact on the pulse. You can select the channels you will examine with a simple keystroke. It is also possible to increase the size of sampling points for the VA-amplifier. Try different sizes and see the impact on the signal. 23

24 The little curl or fit in the figure is a utility to get peaking size in mv and the peaking time in µs. You have to zoom in for the values to make sense, since the curl is making a fit to the curve. Figure 17. a zoom in of the oscilloscope window to get as accurate peaking voltage in mv and peaking time in ms. Figure 18. Oscilloscope, fine resolution. Operation The fine resolution oscilloscope is working in similar manner as the coarse oscilloscope. The only major differences between these two modes are the start and 24

25 end time settings. The end time setting is not working. You can investigate the impact on the signal when adjusting the different biases. Pedestals and Noise Figure 19. Pedestals and Noise. Channel 14 is dead. Operation This option lets you inspect the signal height as a function of input charge. Several of the settings can be adjusted. The program injects a charge samples/charge number of times according to predefined charge selection. The results are displayed in mv. Please see the description for the Setup input charge. 25

26 Gains and Pedestals Figure 20. Gains and Pedestals. Operation This menu let you see the gain differences between the different channels for your VA-amplifier. You can also see the pedestal values for the same channels. When increasing the average you can see the impact on the chip(s). You can print the screen with its result to the default printer for your system. In addition you can save the data to a text file. 26

27 Peaking time versus input charge Figure 21. Peaking time versus input charge. Operation The menu can be used to find the peak signal versus input charge and the peaking time versus input charge. The window located to the bottom of the figure is an oscilloscope displaying the different signal characteristics for each channel. You can also send a screen dump of this window to the default printer of your system. 27

28 Signal height as a function of input charge Figure 22. Signal height as a function of input charge. Operation This utility can be used to find the signal height as a function of the input charge. It is useful if one want to find the working parameters for the VA-amplifier. 28

29 Setup Input Charge Figure 23. Selection of calibration steps/charge. Operation This utility let you specify the calibration charges you would like to use for studies. 29

30 Peaks Figure 24. Gains and pedestals. Operation: Pedestal and gain for each chip/all channels. When using different injected charge, the chip can also be adjusted for optimal performance. With this menu you can also compare the differences between gain and pedestal values for several chips 30

31 8. TA-EVALUATION Low power fast triggering ASIC to be used with a matching VA circuit in the front. The chip includes for each channel a fast CR-RC shaper followed by a level-sensitive discriminator. The trigger signals from each channel are wire-or ed together onto one common trigger output. TA Voltage scan Figure 25. Scan TA threshold voltage to find charge threshold. Operation: This menu let you scan the threshold voltage to find the threshold charge from a user specified start voltage to a user specified end voltage for a given channel.. 31

32 TA Charge scan Figure 26. Minimum trigger charge scan. Operation: Find the minimum trigger charge for the number of channels available. 32

33 Set Threshold Figure 27. Monitoring information. Operation: This utility let you specify the threshold for the TA signal. The monitor value comes from the chip itself. There will be a small difference between the wanted setting and the actual threshold. When selecting the wanted TA threshold value, you select the black bar and move it to wanted value, or you can specify your wanted value in the input box under the selection bar. 33

34 Single channel (TA-triggers as function of input charge) Figure 28. TA-triggers as function of input charge Operation: The upper graph shows charge versus voltage in mv. The lower graph shows the trigger fraction. From about 5 to 18.3 fc there are 0 signal, while between -5 to 18.3 fc there are 100% signal. 34

35 9. DETECTOR READOUT Single Channel Readout of Raw Data Figure 29. Single channel readout. Operation This program is a very sophisticated read out program that let you read out real data generated from a real detector. You can analyze the raw data generated with the VA- DAQ with your favorite software for better understanding of your phenomena. The single channel read out program need some input parameters for optimal operation. This includes, which channel you would like to investigate, how many event you expect to receive, how long time you expect to spend before received these events, to mention a few. One should not forget to adjust the threshold, to make sure you are getting real triggers and not noise triggers. FYI When you are sending the raw data to file, the system will generate a large amount of data. If you have set the How many cycles? to 50, you will get 50 files! 35

36 Full Readout of RAW data Figure 30. Full channel read out. Operation The full readout of raw data let you generate a complete readout of your detector. After running this program you will have several files with data from the run. You can afterwards investigate these data in greater detail with your favorite program. The full readout of raw data program need some input parameters, such as acquisition time and how many events you expect to receive. The program is an enhanced and modified version of the single channel readout RAW DATA FILE FORMAT For both single- and full channel- RAW data readout the files are stored as binary files. The file contains a 16 bits signed integer stream without any delimiter. Each 16 bit integer represents an ADC count. This value can be converted to mv by multiplying with the following factor: 0, For single channel mode: The file contains a 16 bit integer for each event/trigger representing the signal value in the trigger channel. <I16, signal first event ><I16, signal second event ><I16, signal third event ><I16, signal fourth event ><I16, signal fifth event > For full channel mode: For each trigger/event there are N 16 bits integers. Where N is the number of channels. Each 16 bit integer value is the channel value in ADC counts. Not as for the single channel readout where the offset/pedestal is subtracted from the signal value. 36

37 <I16, signal ch 0, first event><i16, signal ch 1, first event> <I16, signal ch N first event> <I16, signal ch 0, second event><i16, signal ch 1, second event> <I16, signal ch N second event> : : <I16, signal ch 0, last event><i16, signal ch 1, last event> <I16, signal ch N last event> Note A run with a 32 channels system receiving 100 trigger we will get the following: 32*100=3200 I16's. 37

38 10. PRESENTATION Nice-plot Figure 31. Nice-plot. Operation Nice-plot let you make a nice plot of the gain, pedestal, and noise of the chip(s) you are testing. 38

39 11. HOW TO CONNECT A DETECTOR TO THE VA-DAQ VA- TA- EVALUATION SYSTEM Introduction VA-DAQ VA-TA Evaluation system let you attach detectors. This enables you to do real measurements and tests with a low budget system. Depending on your system, make sure that you meet the needed requirements before you start to connect a detector to your own VA-DAQ Evaluation system. Also make sure that you have the right software. Please contact IDE AS if you have any questions would like to upgrade your system. Note: connecting a detector is not trivial. Find someone who has the skill needed. This paper is only a brief guide. If you are upgrading your system from the VA adapter board to the VA-TA adapter board, please follow the instruction below. Replacement of VA- to VA-TA adapter board. Replacement of VA adapter board to VA-TA adapter board: 1. Be cautious when removing plastic frames, they are easily damaged. 2. When plastic frames are removed, front and back lids are removed by releasing 8 screws. Then the top of the box is loose also, remove it as well. 3. Take out the 4 screws connecting the cards to the box and slide out the card. Replace adapter board. 4. When mounting be careful to replace all plastic washers, they are important to prevent stress in the board when tightening the screws. Connecting a detector to the VA-DAQ VA-TA- Evaluation system There are two different approaches when you are applying bias voltage to the detector. They are: 1. The connection of the bias voltage is directly on the hybrid detector card. 2. The connection of the bias voltage to the detector is via the VA-DAQ VA-TA- Evaluation system. 39

40 Figure 32. Connecting a detector to the VA-DAQ Evaluation system ERNI 50 Figure 33. Layout of the VA-DAQ Standard VA-TA Adapter. 40

41 Pin 4 9 & 50 Figure 34. Enlarged part of the VA-DAQ Standard VA-TA Adapter. Upper right corner of Figure 33. Layout of the VA- DAQ Standard VA-TA Adapter. The detector bias is connected according to Figure 32. You should use a SHIELDED TWISTED PAIR, NOT COAX, from your bias supply (batteries placed in a metal box) where the shield is connected to the box and to the chassis of the VA-DAQ by the connector. (Do not connect this shield to any of the poles of the battery directly to leave the batteries floating in the box. The reason for using two poles is to avoid having returned currents in the shield. If you use single sided detectors typically the high side of the bias (+side) is connected to the backside and the low side is connected to GND. 41

42 Figure 35. VA-DAQ and test card The + and - sides of the battery are connected to the twisted pair. The -side of the battery is then connected to the ground-pin 49 and the + side is connected to pin 50. On the ERNI connectors pin 49 and pin 50 is accessible with optional LEMO connectors on the adapter card. See Figure 33 and Figure 34. If you use negative bias reverse all the polarities. You can as well by-pass the adapter and connect directly to the hybrids. In that case, be careful to avoid introducing ground loops. In that case shield and the - pole of the twisted pair which is connected to GND as close to the detector as possible. Leave the batteries floating. Remember as well to de-couple the detector with a 1M or 100kohm resistor in series and a 10µF capacitor in parallel with a 100nF ceramic capacitor. It can be advantageous to insert as well a 100kohm resistor in series with the bias in the battery box to avoid accidental damage if the high voltage is connected wrongly. 42

43 Detector bias supply The detector bias supply needs to be of very low noise. The requirements on output voltage stability are however, much smaller as well as the total power to be delivered is very small. Batteries can provide an excellent solution for this. Parameter Output Voltage Table 4. Specifications for detector bias supply Output current/channel Output current (total) Range V adjustable(depending on detector) Max 10µA (1µA typically) 2mA Edge of VA-DAQ interface board Table 5. Pin assignment 2 50 ERNI Table 6. The pin configuration for the VA-TA ERNI 50 interface Pin Signal Pin Signal 1 clkin/vadig5 2 regin/vadig6 3 regout/sig13 4 teston 5 s_outb/sig12 6 spare 7 ckb 8 ck (dummy) 9 s_in (dummy) 10 s_inb 11 dresetb 12 dreset (dummy) 13 hold (dummy) 14 holdb 15 DVDD 16 DGND 17 VDD 18 GND 19 DVSS 20 DGND 21 VSS 22 GND 23 VSS 24 GND 25 outp 26 outm 27 GND 28 ta 29 tb 30 GND 31 Cal 32 Cal_R 33 vref 34 vfp 35 vfs 36 ibuf 37 sha_bias 38 pre_bias 39 vfs_ta 40 vrc_ta 41 vthr 42 nc/obi 43 twbi 44 nc/monwbi 43

44 45 gnd_r/sbi 46 nc/otabi 47 vss_r/en_ta 48 vdd_r/en_va 49 rlemo/gnd 50 llemo/d_bias Pin 49 and 50 connects each to optional LEMO connectors on the adapter boards. See Figure 34 External triggering On the VA-DAQ card there are provisions for an external trigger connection. A TTL signal can be connected to CN1 (right hand side), on the VA-DAQ. The jumper at CN47 has to be moved to CN44. depending on the level of you trigger signal the potentiometer P1 has to be adjusted until stable TTL triggers are observed on the jumper Cn47 with an oscilloscope. A busy signal is available on CN11 centrally placed on the card. This signal goes low when VA-DAQ accepts a trigger and returns to high after acquisition. To get TTL levels on this line terminate with 1kohm 44

45 12. PIN ASSIGNMENT LIST FOR THE FRONT END INTERFACE Introduction This chapter shows the pin assignment list for both Standard-VA and VA-TA adapter boards. Be aware of the special way of numbering pins on the boards. Our number configuration is not similar to the one used by ERNI. The pin numbering is shown in Figure 36. Figure 36. VA-DAQ and test card 45

46 Pin assignment list for the Standard-VA adapter board Table 7 shows the pinassignment of the Standard-VA interface. The pin numbering of the interface is shown in Figure 36. Pin Signal Pin Signal 1 gnd 2 gnd 3 n.c. 4 gnd 5 outm 6 gnd 7 gnd 8 outp 9 Avss 10 gnd 11 Cal 12 Avss 13 Vfs 14 Pre_bias 15 Vfp 16 Sha_bias 17 Vref 18 Ibuf 19 Avdd 20 avdd 21 Cal_r 22 Gnd 23 Vdd_r 24 n.c. 25 Vss_r 26 n.c. 27 Gnd_r 28 n.c. 29 Vfp_r 30 n.c. 31 Extra1 32 Extra2 33 Vdd 34 Gnd 35 Holdb 36 Shift_out 37 Mon10/bi11 38 Ck 39 Dreset 40 Dresetb 41 Shift_inb 42 n.c. 43 Ckb 44 Hold 45 Teston 46 Vss (del_on) 47 Dvdd 48 Dvss 49 Dvdd 50 Dvss Table 7. The pin assignment list for the Standard VA interface Pin names with a _r extention is short for return. These lines are used for monitoring purposes only. n.c. is short for not connected 46

47 Pin assignment list for the VA/TA adapter board Table 8 shows the pin assignment of the VA/TA interface. The pin numbering of the interface is shown in Figure 36. Pin Signal Pin Signal 1 clkin/vadig5 2 regin/vadig6 3 regout/sig13 4 teston 5 s_outb/sig12 6 spare 7 ckb 8 ck (dummy) 9 s_in (dummy) 10 s_inb 11 dresetb 12 dreset (dummy) 13 hold (dummy) 14 holdb 15 DVDD 16 DGND 17 VDD 18 GND 19 DVSS 20 DGND 21 VSS 22 GND 23 VSS 24 GND 25 outp 26 outm 27 GND 28 ta 29 tb 30 GND 31 Cal 32 Cal_R 33 vref 34 vfp 35 vfs 36 ibuf 37 sha_bias 38 pre_bias 39 vfs_ta 40 vrc_ta 41 vthr 42 nc/obi 43 twbi 44 nc/monwbi 45 gnd_r/sbi 46 nc/otabi 47 vss_r/en_ta 48 vdd_r/en_va 49 rlemo/gnd 50 llemo/d_bias Table 8. The pin assignment list for the VA-TA interface Pin 49 and 50 connects each to optional LEMO connectors on the adapter boards. See Figure 34 47