Electronics System Review The Read-Out system for the CMS Drift Tube Chambers. Electronics System Review CERN. November 3rd, 2003

1. 2. 3. 4. 5. 6. Index The Read-Out System. Design Requirements. ESR FOR MUON DT MINICRATE SYSTEM. The Read-Out System. November 3rd , 2003 Index The Read-Out System. Design Requirements. Read Out Board 1. 2. 3. HPTDC (High Performance Time to Digital Converter). ROB architecture and other features ROB validation tests ROB production Conclusions 4. 5. 6.

3 ESR FOR MUON DT MINICRATE SYSTEM. The Read-Out System. November 3rd , 2003 Read-Out System The Read-Out system of the CMS DT chambers is based on the READ OUT BOARDS (ROB). Its aim is: the time digitalization of the incoming signals from the Front-End electronics of the DT chambers. the data transmission to the ROS boards, located in the towers in the periphery of the detector, from there to further levels of the DAQ.

Location in the CMS Detector 4 ESR FOR MUON DT MINICRATE SYSTEM. The Read-Out System. November 3rd , 2003 Location in the CMS Detector 1 Superlayer Φ 1 Superlayer θ Honeycomb MINICRATE ROB

~ 1 kHz muon hits/DT chamber cell. ENVIRONMENTAL RADIATION 5 ESR FOR MUON DT MINICRATE SYSTEM. The Read-Out System. November 3rd , 2003 Design Requirements RATES 40.08 MHz clock 1034 cm-2s-1 luminosity, at 25 ns bunch crossing => 10 Hz/cm-2 charged particles rate. L1 Accept reduces to 1 Hz/cm2 of muons => 250 DT-chambers, a total of 172,200 anode channels. Overlapping triggers due to a drift time of ~400 ns. Trigger latency of 3.2 s. 100 kHz triggers ~ 1 kHz muon hits/DT chamber cell. neutron fluence 10 years < 1010cm-2 charged particles flux < 10 cm-2s-1 10 year integrated dose ~ 1 Gy ENVIRONMENTAL RADIATION Radiation hard devices are not going to be employed, radiation tests have to be performed to every component. OTHERS Stray magnetic fields, in the barrel region around 0.08 Tesla. Limited maintenance for 10 years of operation.

Time Digitization Vdrift ~ constant t ~ x Overlapping 6 ESR FOR MUON DT MINICRATE SYSTEM. The Read-Out System. November 3rd , 2003 Time Digitization Vdrift ~ constant Tmax drift time~400 ns >> Tbunch crossing 25 ns 1 2 3 4  Overlapping t ~ x 2 3 1 4 Bunch crossing Drift Time L1 Accept Latency Trigger Time measurement with respect to L1 Accept

(High Performance Time to Digital Converter) 7 ESR FOR MUON DT MINICRATE SYSTEM. The Read-Out System. November 3rd , 2003 HPTDC (High Performance Time to Digital Converter) Developed by the CERN/EP-MIC group, and produced by IBM in 0.25 m CMOS technology.  4 registers/channel before L1 buffer.  4 L1 buffers of 256 words, each shared by 8 channels.  Triggers stored in 16 words deep FIFO.  256 words deep readout FIFO.

HPTDC OTHER FEATURES LHC clock operation (40.08MHz). ESR FOR MUON DT MINICRATE SYSTEM. The Read-Out System. November 3rd , 2003 HPTDC OTHER FEATURES LHC clock operation (40.08MHz). Highly programmable which provides flexibility. High integration, 32 channels per chip. Overlapping trigger handling. Trigger latencies (50 μs) large enough to accommodate our requirements (3.2μs). Time resolution of ~265 ps RMS in low resolution mode (Required resolution~1ns) Implemented in a radiation tolerant technology, up to levels of 30 Krad total dose with slight increase in power consumption. Up to 2MHz hit rates, much more than our needs (noisy channels ~ tens of KHz). Minimum time between pulses ~10 ns. Up to 1 MHz trigger rates, enough for 100 KHz maximum estimated. Bunch and event identification. JTAG port for programming and monitoring. Flexible read-out interface: parallel, serial or byte-wise. Error flags signalling lost of events, TDC internal errors, etc. and self-bypass on error.

ROB Architecture JTAG INTERFACE DIAGRAM 4 HPTDC/ROB (128 channels) 9 ESR FOR MUON DT MINICRATE SYSTEM. The Read-Out System. November 3rd , 2003 ROB Architecture JTAG INTERFACE DIAGRAM 4 HPTDC/ROB (128 channels) Compromise between #boards and #unused channels.  A JTAG interface for configuration and monitoring.  Clock synchronous token ring passing scheme where one TDC is configured as Master.  Bypass on error mechanism implemented. Serializer parity) clock READ-OUT INTERFACE DIAGRAM

Other ROB Features READ-OUT POWER SUPPLY 32 bits/HPTDC word 10 ESR FOR MUON DT MINICRATE SYSTEM. The Read-Out System. November 3rd , 2003 Other ROB Features READ-OUT 32 bits/HPTDC word Master header and trailer Error signaling Timing and positional information (# TDC and # channel). Byte-wise readout (8 bits data+1 parity+2 byte ID) DS92LV1021 serializer (12 bits: 10 data + 2 start/stop) at 20 MHz. POWER SUPPLY Power consumption: 2.5 V (0.5A) and 3.3V (0.5A) ~ 4 W => ~ 6kW whole system. Power supply protection circuitry: In case of 2.5V current consumption over 1.5 A or 3.3V over 1A, power supply is disconnected, with powering on cycles every 700 ms (reduces to 10% power consumption). Sensor on board for temperature, 2.5V and 3.3V voltage and 2.5 V current monitoring. (Maxim DS2438).

ALTERA CPLD CONTROLLER 11 ESR FOR MUON DT MINICRATE SYSTEM. The Read-Out System. November 3rd , 2003 Other ROB Features ALTERA CPLD CONTROLLER - An Altera CPLD (EPM7128AE) manages the the Data_Ready/Get_Data transmission protocol slowing down the readout frequency to 20 MHz. - Manages the channels enabling mechanism for testing chambers during spill interleaves, simulating artificial tracks. - Controls bytes order from HPTDC words. Triple redundancy on ALTERA FPGA registers. Allows detection and reparation of 1 bit upset in a CPLD register due to Single Event Upsets (SEU) from radiation. (Updated every 25 ns). d 1 2 3 q FF1 FF2 FF3 SEU <= (FF1 xor FF2) or (FF1 xor FF3) or (FF2 xor FF3) Also a SEU counter implemented for radiation tests.

12 ESR FOR MUON DT MINICRATE SYSTEM. The Read-Out System. November 3rd , 2003 Test Pulses mode Mode operation for testing chamber channels and electronics during spill interleaves, simulating artificial tracks. Originated by a TTC command. CCB enables/disables the different channels of the Front-End boards and ROB´s to simulate individual vertical tracks. Front-End generates the Odd and Even signals of the corresponding layer, delayed one with respect to the other to simulate a vertical track on any position of the cell. (Trigger system test). Altera CPLD manages the mechanism of enabling/disabling accordingly the ROB LVDS receiver channels. Enable TDC 0 ch 0-3 Enable TDC 0 ch 0-7 Enable TDC 0 ch 7-12 TEST MODE ... T1 T2 T3

13 ESR FOR MUON DT MINICRATE SYSTEM. The Read-Out System. November 3rd , 2003 ROB Connections 128 LVDS signals from DT chambers. Transmitted to Trigger logic, previously converted to TTL level. ROBUS (RO-MC control bus): Independent point to point clock connections are used to minimise interference effects. FTP Cat.6 cable for ROB-ROS link. - Independent powering up signals (up to 7 ROB´s) - ROB address lines (4, up to 15 boards) - JTAG lines - other control lines (test pulses...) TRB connections From DT chambers 3.3V power supply 22.6 cm 9.8 cm Thermal dissipation areas ROBUS (back) 40MHz clock ROB-ROS link

ROB-ROS link Read Out Boards (ROB) CMS DETECTOR DDU 14 ESR FOR MUON DT MINICRATE SYSTEM. The Read-Out System. November 3rd , 2003 ROB-ROS link DT chamber Read Out Boards (ROB) Towers Read Out Server boards (ROS) Link bandwidth: 240 Mbps. Throughput: 16Mbps. Measured BER < 10-15 30m FTP Cat. 6 AC coupled LVDS link 1500 DDU USC55 Control Room 100 m. Optical link Link max. Bandwidth: 800Mbps. Throughtput: 270Mbps. 60 CMS DETECTOR

Minicrate (MC) MINICRATE 250 Minicrates 1500 ROB´s: -1440 Rob-128 ESR FOR MUON DT MINICRATE SYSTEM. The Read-Out System. November 3rd , 2003 Minicrate (MC) 250 Minicrates 1500 ROB´s: -1440 Rob-128 -60 ROB-32 MB1 MB2 MB3 MB4 Power supply 3.3V @ 40A 5V @ 1.5A to ROS MINICRATE TRB TRB TRB SB Chamber signals Link board RO- Link board ROBUS ROB ROB CCB ROB 40 MHz CLOCK RO-link TTC+Slow control

IRRADIATION FACILITY, GIF. (CERN) 16 ESR FOR MUON DT MINICRATE SYSTEM. The Read-Out System. November 3rd , 2003 ROB Validation Tests TEST BEAMS AT GAMMA IRRADIATION FACILITY, GIF. (CERN) Time (ns) Nº events Time box Oct. 01: test beam at GIF. Including a 25 ns structured beam ~ 5 Ktrig/s. MB2 chamber operated under real gas and voltage conditions. With and without gamma background during acquisition. May. 03: One full Minicrate operational with a Ros-8 prototype. Validation with overlapping triggers No significant errors were found neither in HPTDC nor in the ROB design, (incorrect wordcount when using local headers). TDC can stand high hit rates, including noisy channels (~MHz) and this only affects 1 group of 8 channels.

ROB Validation Tests IRRADIATION TESTS 17 ESR FOR MUON DT MINICRATE SYSTEM. The Read-Out System. November 3rd , 2003 ROB Validation Tests IRRADIATION TESTS Cyclotron Research Centre at the Catholic University of Louvain (UCL), Belgium. 60 MeV proton irradiation. Fluence: 5·1010 p.cm-2 SEU: MTBFHPTDC = 3.8 days in the whole detector MTBFALTERA = 3.4 days in the whole detector Regulators (MIC29151-3.3BU, MIC39151-2.5BU): ΔV<1% Rest of ROB IC´s: No effect

ROB Validation Tests TEMPERATURE CYCLING LIFETIME TESTS 70ºC 0.2ºC/min 18 ESR FOR MUON DT MINICRATE SYSTEM. The Read-Out System. November 3rd , 2003 ROB Validation Tests TEMPERATURE CYCLING 70ºC 0.2ºC/min 0ºC - Regulators: Small variations (< 5mV/30ºC). - 2.5V current variations of 0.4 mA/ºC. - Timing measurement variation: 900 ps/70ºC (14 ps/ºC). Max variation ~ 45 ps/ºC. 30% due to LVDS receivers (DS90LV048). LIFETIME TESTS - ROB fully operational at 105ºC ambient temperature for 4 months (3100 hours). - No device has shown any failure.

ROB Validation Tests Time resolution Time shift < 200 ps 19 ESR FOR MUON DT MINICRATE SYSTEM. The Read-Out System. November 3rd , 2003 ROB Validation Tests Time resolution Neighbour channels crosstalk Time measurement shift in one ROB channel due to neighbour signals. Time shift < 200 ps Low resolution bin size: 0.781 ns Measured resolution: 265 ps Link reliability RO link to ROS-8 prototype has been tested using a TTC system (TTCvi, TTCex, TTCrx). Measured jitter on ROB with TTC clock: ~40ps RMS; ~380ps pk-pk BER < 10-15 No observed influence of TTC commands.

20 ESR FOR MUON DT MINICRATE SYSTEM. The Read-Out System. November 3rd , 2003 ROB Production  Several prototypes of ROB´s have been made, we are now confident on its operation.  PCB´s for ROB-128 and ROB-32 have already been produced.  An error was found in the engineering run of the HPTDC that never showed up before, presumably due to metallization process.  Its consequence is a very low yield of the produced HPTDC´s. Exhaustive tests that identify the error have been developed.  Production run showed 350 “good” HPTDC´s received in September, they will be used for: - 180 ROB´s of the first assembly batch. - Produce all ROB-32: 60+spares.  Whole final production batch of HPTDC´s, now being packaged, will be available in December (6000 u.) - Remaining ROB-128 will be produced then.

ROB Production  Assembly is done at the industry: Assembly 21 ESR FOR MUON DT MINICRATE SYSTEM. The Read-Out System. November 3rd , 2003 ROB Production  Assembly is done at the industry: Assembly On error: repairing Connectorization tests. On error: repairing Functional test.  A test that checks every functionality of the ROB has been developed at Ciemat to validate assembled ROB´s at the industry.

22 ESR FOR MUON DT MINICRATE SYSTEM. The Read-Out System. November 3rd , 2003 ROB Production  Before assembling ROB´s in the Minicrates, they will go through a BURN-IN process: - We do not want to over-stress the boards, only find infant mortality. - 15 days at 60ºC ambient temperature powered and clocked.

23 ESR FOR MUON DT MINICRATE SYSTEM. The Read-Out System. November 3rd , 2003 Conclusions The design and operation of the ROB has been thoroughly tested with satisfactorily results. It meets the imposed requirements of reliability and accuracy. We are confident in the proper operation of these boards inside the CMS environment within the expected radiation levels, trigger and data rates, etc. Accordingly, the Read-Out Board is ready for final production and installation on Minicrates.