Surface Concept Preamplifier-CFD User manual

1-Channel & 4-Channel
Preamplier-CFD
Manual

2
Surface Concept GmbH
Am Saegewerk 23a
55124 Mainz
Germany
phone: [phone]
fax: [phone]
email: [e-mail]
web: www.surface-concept.de
All rights reserved. No part of this manual may
be reproduced without the prior permission
of Surface Concept GmbH.
User Manual for the
1-Channel Preamplier-CFD R007
& 4-Channel Preamplier-CFD R011
Manual Version 2.3
Printed on 2020-10-20

3
Preamplier-CFD Manual
1 Table of Contents ......................................................................................................................3
2 General Information ................................................................................................................5
2.1 General Information & Safety Instructions................................................................5
2.2 General Overview of the System ..................................................................................5
3 CFD - Principle of Operation .................................................................................................7
3.1 CFD - Principle of Operation...........................................................................................7
4 Technical Specication............................................................................................................9
4.1 Layout of Front Panel........................................................................................................9
4.2 Input/Output Features .................................................................................................. 11
4.2.1 Input Features........................................................................................................ 11
4.2.2 Output Features.................................................................................................... 11
4.2.3 Measurement Parameters ................................................................................. 11
4.3 CFD Adjustment ............................................................................................................. 11
4.3.1 Adjustment of CFD Threshold.......................................................................... 11
4.3.2 Adjustment of Zero Oset................................................................................. 11
4.3.3 Adjustment of the Asymmetry........................................................................ 12
4.3.4 Procedure for Walk Minimization ................................................................... 12
4.4 Power Requirements ..................................................................................................... 12
5 List of Figure ............................................................................................................................13
1 Table of Contents

4
This side has been left blank on purpose.

5
Preamplier-CFD Manual
2 General Information
2.1 General Information & Safety Instructions
This manual is intended to assist users in the operation of the 1-Channel Preamplier-CFD R007 and
4-Channel Preamplier-CFD R011. It is divided into 4 chapters.
Surface Concept strongly recommends reading this manual carefully before operating the Preamplier-
CFD. Surface Concept declines all responsibility for damages or injuries caused by an improper use of
the Module due to negligence on behalf of the User.
2.2 General Overview of the System
The Surface Concept Preamplier-CFD devices are a combination of a preamplier with variable gain (typ.
13dB to 30dB) and a constant fraction discriminator (CFD) housed in a RF-shielded stand-alone (R007) or
19” (R011) housing. The device accepts 1 analog negative or positive input (BNC connector) and produces
1 LVTTL output (BNC connector) and 1 NIM output (LEMO connector) per channel. It is equipped with an
additional monitor output (BNC) for the amplied analog signal.

6
This side has been left blank on purpose.

7
Preamplier-CFD Manual
3 CFD - Principle of Operation
3.1 CFD - Principle of Operation
The technique of the constant fraction discriminator (CFD) is based on summing the original input signal
to an inverted signal. The original input signal is delayed but of full height, while the inverted signal is
attenuated.
The resulting signal is fed into a zero-crossing comparator. This allows obtaining precise timing
information that eliminates any walk error, which is induced by constant rise time and varying signal
amplitudes.

8
This side has been left blank on purpose.

9
Preamplier-CFD Manual
4 Technical Specication
4.1 Layout of Front Panel
Figure 1: Front Panel of 1-Channel Preamplier-CFD
1
2 3
4
5 6 7
8 9 10
11
12 13 14
Figure 2: Front Panel of 4-Channel Preamplier-CFD
1
Figure 3: Back Panel of 4-Channel Preamplier-CFD
2 3
4
5 6 7 9
10
11
12 13 14
15
16
17

10
1. BNC Input for Negative Analogue Signal
2. Regulator for Variable Gain of Preamplier
3. Switch for Pulse Input Polarity (neg. or pos.)
4. BNC Monitor Output for Amplied Analogue Signal
(Recommendation: use AC-coupled measurement mode when observing the signal with an
oscilloscope)
5. Regulator for the Asymmetry (Asy)
6. Regulator for the Zero Oset (Z)
7. CFD Threshold (Th) Regulator
8. 5 PIN Power Connector
9. Lemo Output for CFD NIM Signal
10. BNC Output for CFD LVTTL Signal
11. CFD Operation Monitor LED
12. Monitor Output for the Zero Oset [Z]
13. Monitor Output for the Threshold [Th]
14. Monitor Output for Ground [GND]
15. Power Switch to turn the device ON/OFF. Lighted, when set to ON.
16. Device Ground Connection
17. Power Socket