Technical Information Manual

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1 Technical Information Manual Revision n January 1996 MOD. N417 8CHANNEL LOW ESHOLD DISCRIMATOR

2 Table of Contents 1. DESCRIPTION FUNCTIONAL DESCRIPTION SPECIFICATIONS PACKAGG EXTERNAL COMPONENTS TERNAL COMPONENTS POWER REQUIREMENTS CHARACTERISTICS OF THE SIGNALS OPERATG MODES GENERAL FORMATION OPERATIONS TO BE PERFORMED TEST PROCEDURE TRODUCTION NECESSARY STRUMENTS PROCEDURE...9 APPENDIX A: ELECTRICAL DIAGRAMS...A1 APPENDIX B: COMPONENTS LIST AND LOCATIONS...B1 i

3 1. DESCRIPTION 1.1. FUNCTIONAL DESCRIPTION The CAEN model N CHANNEL LOW-ESHOLD DISCRIMATOR is a oneunit wide NIM module equipped with 8 independent non-updating discriminating channels. Each channel accepts both negative and positive high-impedance input signals in the range from 1.5 mv to 250 mv (absolute values). Two parallel inputs ("" connectors) per channel are provided: the unused connector allows the user to terminate the input signal appropriately. For each channel, whichever threshold value can be set in the above mentioned range through the relevant "" front panel trimmer and the corresponding test point. A 4- jumper group ("JP1,JP2,JP3,JP4") located on the printed-circuit board allows the setting of the threshold polarity in accordance with the input signal polarity; the front panel LED ("+" or "-") corresponding to the selected polarity lights up at power on. For each channel are available on the front panel two standard NIM outputs (normal and complementary) are available: "" "" Normal Complementary The output signal width is adjustable via front panel control ("" trimmer) in the range from 5 ns to 140 ns or in the one from 15 ns to 800 ns. An internal jumper determines the actual width range. 1

4 JP6 DISCRIMATOR 5 ns to 140 ns WIDTH POLARITY SELECTION JP5 15 ns to 800 ns WIDTH (JP1,JP2,JP3,JP4) ESHOLD ADJUSTMENT + - CHANNEL n Fig. 1.1: Mod. N417 block diagram 2

5 2 SPECIFICATIONS 2.1. PACKAGG One-unit wide NIM module EXTERNAL COMPONENTS (see fig. 2.1.) CONNECTORS - No. 16, "" (two bridged connectors per channel), LEMO 00 type connectors, > 100 KΩ impedance; input connectors for the input signals. Each unused connector must be terminated according to the input signal impedance. - No. 8, "" (one per channel), LEMO 00 type connectors, std. NIM level on 50Ω impedance; channels' output signal connectors (normal signal). Each unused connector must be terminated in50 Ω. - No. 8, "" (one per channel), LEMO 00 type connectors, std. NIM level on 50Ω impedance; channels' output signal connectors (complementary signal). Each unused connector must be terminated in 50Ω. LEDs - No. 8 "+" red LEDs (one per channel) signalling, when alight, that a positive polarity has been selected for the relevant channels. - No. 8 "-" green LEDs (one per channel) signalling, when alight, that a negative polarity has been selected for the relevant channels. TRIMMERS - No. 8, "" (one per channel), for adjusting the output width in the selected range (5 ns to 140 ns or 15 ns to 800 ns). - No. 8, "" (one per channel), for adjusting the threshold level in the work range (1.5 mv to 250 mv absolute values). TEST POTS - No. 8, "" (one per channel), for monitoring the threshold level. 3

6 2.3. TERNAL COMPONENTS - No. 8 4-jumper groups (one per channel), labelled "4,1,2,3". Two-position jumpers for selecting a positive ("+" position) or negative ("-" position) polarity according to the input signal polarity. - No. 8 1-position jumpers JP6 (one per channel), without label, for selecting an output width range from 5 ns to 140 ns. To select this width range, insert the jumper and remove JP5 (if present). See figure No. 8 1-position jumpers JP5 (one per channel), without label, for selecting an output width range from 15 ns to 800 ns. To select this width range, insert the jumper and remove JP6 (if present). See figure POWER REQUIREMENTS + 12 V - 12 V + 6 V - 6 V 300 ma 250 ma 70 ma 1.5 A 2.5. CHARACTERISTICS OF THE SIGNALS - PUTS: High impedance (> 100 KΩ). DC coupled. Polarity: positive or negative. Max. amplitude: 250 mv absolute value. Threshold polarity: positive or negative, selectable via internal jumpers according to the input signal polarity. Threshold level: adjustable in the range from 1.5 mv to 250 mv absolute values. - PUTS: Std. NIM level (one normal signal and one complementary signal) Width: adjustable, via front panel trimmer, in the range from 5 ns to 140 ns or in the one from 15 ns to 800 ns. Width range selectable via internal jumper. Fall time: 1 ns. Rise time: 1.5 ns. - GENERAL: Non updating operation. Max. rate: > 100 MHz. Input/Output delay: 10 ns. Double pulse resolution: 9 ns, measured with the following conditions: input signal amplitude = 200 mvpp; input signal width = 2 ns FWHM; fall time = 1.5 ns; rise time = 1.5 ns; threshold = 100 mv; output signal width = 5 ns. 4

7 C.A.E.N. 8 CH LOW DISCRIMATOR Mod. N417 Ser. n. Fig. 2.1: Mod. N417 Front panel 5

8 Components side CAEN MOD. N417 R20 R20 R20 R20 R20 R20 R20 R20 JP6 JP6 JP6 JP6 JP6 JP6 JP6 JP6 JP5 JP5 JP5 JP5 JP5 JP5 JP5 JP5 Fig. 2.2: Mod. N417 internal jumpers 6

9 3. OPERATG MODES 3.1. GENERAL FORMATION The N417 module houses 8 independent low-threshold discriminator channels. Each channel is provided with: - two parallel high-impedance inputs ("" connectors) capable of accepting positive or negative signals with a 250 mv maximum amplitude (absolute value). One of these inputs receives the signal, the other one must be terminated according to the input signal impedance. - one normal output and one complementary output both std. NIM level:. "" connector: "" connector: Normal output Complementary output The unused output connector must be terminated on 50 Ω impedance. - one front panel trimmer "" (with test point) that allows the setting of the desired threshold level (1.5 mv to 250 mv absolute values). - one 2-position 4-jumper group "4,1,2,3" (on the printed-circuit board) that allows the setting of the threshold polarity ("+" position = positive; "-" position = negative) according to the input signal polarity. - one 1-position jumper JP6 (on the printed-circuit board) that allows to select an output width range from 5 ns to 140 ns (see figure 2.2 for jumper location and setting). - one 1-position jumper JP5 (on the printed-circuit board) that allows to select an output width range from 15 ns to 800 ns (see figure 2.2 for jumper location and setting). - one front panel trimmer "" that allows to set the desired output width value in the actual width range OPERATIONS TO BE PERFORMED 1. Before using the module, perform the following operations for each channel: (a) Set the 4-jumper group "4,1,2,3" (located on the printed-circuit board) to the "+" or "-" position according to the polarity of the input signal to be used. Note: at power on, the front panel LED corresponding to the selected polarity lights up. (b) Select the width range of the output signal by inserting the corresponding jumper (JP6 selects a width range from 5 ns to 140 ns; JP5 selects a width range from 15 ns to 800 ns). Remove the other jumper, if present. (c) Terminate each unused connector with an appropriate load. 7

10 (d) Connect a voltmeter to the front panel test point. (e) With a screwdriver, turn the front panel trimmer "" until the desired threshold level is reached. (f) Connect an oscilloscope to the "" connector to be used. (g) With a signal generator, supply the "" connector with an appropriate signal. (h) With a screwdriver, turn the front panel trimmer "" until the desired width value is reached. 2. Remove voltmeter, oscilloscope and signal generator. 3. Connect the "" connectors to the signal sources and the "" connectors to the respective devices. THE MODULE IS NOW READY TO USE 8

11 4. TEST PROCEDURE 4.1. TRODUCTION The operations to be performed to test the N417 module are listed in the procedure below and have to be carried out according to their numerical order. None of the procedural steps can be omitted NECESSARY STRUMENTS - No. 1 pulse generator. - No. 1 oscilloscope. - No. 1 voltmeter PROCEDURE 1. For each channel, perform the following operations: CAUTION: Always terminate the unused input and output connectors with appropriate loads. (a) Set the 4-jumper group "4,1,2,3" (located on the printed-circuit board) to the "-" position. (b) On the printed-circuit board, insert the JP6 jumper (remove the JP5 jumper, if present): an output width range from 5 ns to 140 ns is set. (c) Power the module and verify that the green LED "-" of the selected channel lights up. (d) Connect a voltmeter to the front panel test point of the selected channel. (e) With a screwdriver, turn the front panel trimmer "" of the selected channel and verify that the threshold value can be continuosly varied in the range from mv to mv, then set a -100 mv threshold. (f) With the pulse generator, supply one of the "" connectors of the selected channel with a signal having the following characteristics: - negative polarity. - amplitude = mvpp. - leading and trailing edges between 2 ns and 3 ns. - frequency = 200 KHz. (g) With the oscilloscope, verify that a correct signal is present at each of the output connectors. (h) Repeat steps (f) and (g) for the remaining "" connector. (i) With a screwdriver, turn the "" trimmer of the selected channel and verify that the output width can be set up to 140 ns. 9

12 (j) On the printed-circuit board, insert the JP5 jumper and remove JP6, then turn the "" trimmer and verify that the output width can be varied in the range from 15 ns to 800 ns. (k) Set the output width to 50 ns. (l) Turn the "" trimmer until the output signal switches off and on. In this condition verify that a threshold level of about mv is present at the relevant test point. (m) Set the input signal amplitude to - 5 mv. (n) Turn the "" trimmer until the output signal switches off and on. In this condition verify that a threshold level of about - 5 mv is present at the relevant test point. 2. Switch the power off. 3. Set the 4-jumper group "4,1,2,3" to the "+" position. 4. Perform the operations (c) to (g) and (l) to (n) listed in step 1. by setting positive values instead of the negative ones (the red LED "+" lights up). 10

13 APPENDIX A: ELECTRICAL DIAGRAMS A.1

14 1/d/yy N417 User's Manual APPENDIX B: COMPONENTS LIST AND LOCATIONS * b.1

15 1/d/yy N417 User's Manual b.2

Technical Information Manual

Technical Information Manual Revision n. 5 25 November 2002 MOD. N840-N841 8-16 CHANNEL LEADING EDGE DISCRIMINATOR NPO: 00103/00:840-1.MUTx/05 CAEN will repair or replace any product within the guarantee