LW800 800 MHz Discriminator with fiber optical isolation User Manual copyright FAST ComTec GmbH Grünwalder Weg 28a, D-82041 Oberhaching Germany Version 1.
Warranty Warranty Copyright 2005 FAST ComTec GmbH, Grünwalder Weg 28a, D-82041 Oberhaching Germany All rights reserved. This manual contains proprietary information. No part of it may be reproduced by any means without prior written permission of FAST ComTec GmbH, Grünwalder Weg 28a, D-82041 Oberhaching, Germany. Tel: ++49 89 665180 50, FAX: ++49 89 665180 40. http://www.fastcomtec.
IMPORTANT NOTES IMPORTANT NOTES The TX800 contains a Class 1M LASER diode for signal transmission. Please use appropriate LASER safety precautions when handling. Do not look into the invisible LASER beam, as LASER radiation can be potentially harmful. The power supplies for both modules TX800 and RX800 must be floating. When using the TX800 module at high voltage levels take care to use a power supply with sufficient isolation voltage capabilities.
Table of Contents Table of Contents 1. Introduction .............................................................................................................................. 1-1 2. Installation / Setup Procedure.................................................................................................. 2-1 2.1. Cable connections....................................................................................................... 2-1 2.2. Threshold level..........................................
Table of Figures Table of Figures Figure 1.1: Block diagram / principle of operation ........................................................................ 1-1 Figure 2.1: LW800 Scope of supply.............................................................................................. 2-1 Figure 2.2: LW800 connections .................................................................................................... 2-2 Figure 2.3: TX800 Discriminator / Transmitter top view............................
Introduction 1. Introduction The LW800 is an ultra fast fiber optically isolated leading edge Discriminator system. It consists of the 800MHz Discriminator / Transmitter Module TX800 and the Receiver / Output Module RX800. The fiber optically coupling between the TX800 and RX800 modules is ideally suited for decoupling ultra high count rate timing signals from detectors at high voltage levels.
Installation / Setup Procedure 2. Installation / Setup Procedure The delivery of a LW800 system includes a TX800 Discriminator / Transmitter module, a RX800 Receiver / Output module, a 50/125µm fiber cable of 2m in length and two AC adapters. A spare low voltage connector is also provided. It might be used for connecting a custom-made power supply e.g. a battery pack to power the TX800 module.
Installation / Setup Procedure It is recommended to use only the supplied fiber cable. Longer cables might lead to reduced signal quality. The longer the cable the more does the mode dispersion lead to pulse broadening and thus, to a reduced signal quality of the received optical pulse. Plug in the power supplies.
Installation / Setup Procedure Connect the inverting and/or non-inverting fast NIM output. Use 50Ω coaxial cables with appropriate 50Ω termination. 2.2. Threshold level To control the threshold voltage level connect a high impedance (≥ 10MΩ) digital voltmeter to the THRESHOLD MONITOR output. Adjust the threshold level according to your input signals. In general, the best performance is achieved at about 50% pulse height.
Installation / Setup Procedure Figure 2.
Appendix 3. Appendix 3.1. Performance Characteristics Bandwidth: ........................................................................................ ≥ 800MHz1 Pulse width high/low: ............................................................................................. > 625ps Time Resolution: ......................................................................................
Appendix 3.2.4. TX800 Connectors Signal input Connector: ....................................................................................... female BNC Impedance: .................................................................................................... 50Ω Input voltage range: ................................................................................................ ± 1.2V Input sensitivity: ......................................................................................
Appendix 3.2.6. Fiber cable Type: .......................................................................................... 50/125µm Length: recommended ......................................................................... ≤ 2m Connector: .................................................................................. optical ST-type 3.2.7. Physical Case size: each module ........................................... approx. 35 x 85 x 150mm Weight (module alone): TX800 ...................
