From: Jan Michel <j.michel@gsi.de>
Date: Wed, 17 Jul 2013 16:45:25 +0000 (+0200)
Subject: few more details
X-Git-Url: https://jspc29.x-matter.uni-frankfurt.de/git/?a=commitdiff_plain;h=e42193acdf09c4b2ac4001a6051da46ddbd224d9;p=mvd_docu.git

few more details
---

diff --git a/electronics/electronics2013.tex b/electronics/electronics2013.tex
index 528c3b1..995a30d 100644
--- a/electronics/electronics2013.tex
+++ b/electronics/electronics2013.tex
@@ -44,6 +44,10 @@ If there is a special AddOn later on, it could have these features:
 }
 
 \section{Cable TRB to CB}
+The 40-pair twisted pair flat cable used for TDC applications at GSI provides all connectivity for
+one converter board. The cables can be made in any length, so we can do studies about the maximum
+length. \final{The final setup will most likely use different cables with better shielding and
+improved handling.} Cables as well as connectors will be bought by GSI.
 
 \begin{table}[htp]
  \centering
@@ -84,20 +88,26 @@ amplification of 50 - 100. In total, 7 single ended plus 4 differential ADC chan
 sensor.
 
 The on-board ADC should provide at least 1 MSPS and a SPI (or similar) interface. AD7928 is a
-possible candidate. If necessary, an external monitoring board can be connected for testing
-purposes. Such a TRB3-AddOn is currently in preparation at GSI (52 channels, 12 Bit, 40 MSPS).  
+possible candidate for single ended measurement. It can also provide the differential measurements
+if a pre-amplification stage with OpAmps is included if a dedicated ADC is not available.
+If necessary, an external monitoring board or oscilloscope can be connected for testing purposes.
+Such a TRB3-AddOn is currently in preparation at GSI (52 channels, 12 Bit, 40 MSPS).  
 
 Current sensing can be implemented with dedicated current monitors, e.g. TSC101 to reduce count of
 components.
 
 \subsection{Board Control}
 All voltages are switchable from FPGA. The JTAG chain needs the option to disable individual
-sensors. Both features can make use of a 74HC259 IC to reduce number of lines.
+sensors. Both features can make use of a 74HC259 IC to reduce number of lines. This chip also
+provides the CE signals for ADCs if needed.
 
 
 \subsection{Connectivity}
-All communication to the TRB3 should be differential, despite on some static signals. Test pads for
-most signals should be added to connect external, more precise instruments.
+All communication to the TRB3 should be differential, maybe despite on some static signals. Test
+pads for most signals should be added to connect external, more precise instruments.
+
+All signals from and to the sensor should be fed through LVDS buffers to reduce the load on the
+sensors' output drivers and to improve signal quality.
 
 
 \subsection{Test Features}