Table 1
ASDBLR main characteristics:
Channels 8
Dynamic range for low-level thresholds 1.5-15fC
Dynamic range for high-level thresholds 10-150 fC
Operating threshold 2fC (200eV)
Noise counting rate at operating threshold less than 30kHz
Peaking time about 8ns
Width of signal at base about 20ns
Overshoot area about 5-20%
Signal amplitude uniformity for 75cm long straw for high level threshold better than 10%
Minimum discriminator output signal width 5ns
Maximum discriminator dead time 5ns
Low-level threshold uniformity +-15%
High-level threshold uniformity +-10%
Input impedance 270-300W at low frequency
Channel-to-channel crosstalk less than 0.5%
Power consumption 35mW/channel
DTMROC main characteristics:
Channels 16
Timing measuremets 3 ns binning
Pipeline length 3.2ms (128 LHC bunch crossings)
Bunch-crossing number and event number stored with the data  
Readout of 3 consecutive time-slices on receipt of L1A  
Read-out dead-time Below 1% at 75kHz L1A rate
Serial data read-out 40Mbit/s
ASDBLR threshold setting 6 bit
Programmable test pulse 1 bit, 2 phases
Power consumption 10mW/channel


Radiation Hardness

The TRT front-end electronics will be subject to the radiation levels given in Table 2. The TRT strategy concerning the radiation hardness is based on the ATLAS general policy, namely:
Design for two technologies.
  The ASDBLR has been designed in Maxim bipolar technology which has proven to be sufficiently radiation hard. A version in DMILL will be designed in 1997. The DTMROC will be designed in DMILL and in Honeywell Bulk or SOI. The BiCMOS version can only be designed in DMILL as it is the only process allowing BiCMOS design.
Testing functionality after irradiation.
  Using radiation-hard technologies is not enough to guarantee that a chip is radiation-hard. Thus extensive tests of the functionality after irradiation will be performed for each design.
Formal design review before production.
  Before launching the production, a formal design review of each component will be organised within ATLAS.


The present version of the ASDBLR operates with little or no degradation after an exposure to protons equivalent to 50 kGy and approximately 11014neutrons/cm2. All the components which are going to be installed on the detector (printed circuit boards, capacitors, resistors, connectors, cables,...) will also be subject to irradiation tests.

  Dose
(kGy)
Neutron fluence
(cm)-2
Barrel TRT 33 1.01014
End-cap TRT 17 1.01014

Table 2 Maximum integrated dose and neutron fluence seen by the TRT front-end electronics durin ten years of operation at the LHC.