1 Hall D Drift Chamber ElectronicsFJ Barbosa Drift Chamber Review6-8 March 2007 Electronics for CDC and FDC Hall D 1.Motivation 2.ASIC Development 3.Preamp Cards 4.Cabling 5.Cooling 6.fADCs 7.TDCs 8.HV, LV & Grounding 9.Summary F.J. Barbosa, Jlab Central Drift Chambers (CDC) Forward Drift Chambers (FDC)

2 Hall D Drift Chamber ElectronicsFJ Barbosa Drift Chamber Review6-8 March MotivationA Brief Summary of Specifications TypeStrawPlanar Channel Count3200 anodes2304anodes 9216cathodes Physics Signal225 e94 e Energy Resolution 15%15% Time Resolution2 ns1 ns Detector Gain2 x Dynamic Range100 fC → 3 pC300 fC → 3pC anodes 10 fC → 1 pC cathodes dE/dxYesNo Preamp Gain2 mV/fC2 mV/fCanodes 10 mV/fCcathodes Single Channel3kHz kHz< 280 kHz anodes Rate< 600 kHz cathodes TDCNoanodes: Yes 115 pscathodes: No fADCYesanodes: No 12-bit, 100MSPScathodes: Yes CDCFDC

3 Hall D Drift Chamber ElectronicsFJ Barbosa Drift Chamber Review6-8 March HV R C Cathode Strips Anode Wire Ionizing Track Preamp fADC TDC fADC Pipelined DAQ HV R C Straw Tube Anode Wire Ionizing Track fADC GND FDC CDC Generalized Readout Electronics For the cathode strips, q+ ~ 1/5 q- Disc

4 Hall D Drift Chamber ElectronicsFJ Barbosa Drift Chamber Review6-8 March Application Specific Integrated Circuit (ASIC) Development The GlueX Preamp ASIC is Being Designed by Mitch Newcomer at U. Penn., the Designer of the ASDQ ASIC – used at CDF at FNAL. This Development is Based on the ASDQ ASIC: Input Protect Preamp, Shaper & BLR Discriminator & dE/dx Output Driver The ASDQ ASIC was Fabricated in a Bipolar Technology which is no Longer Available (Maxim SHPi). ASDQ Functional Blocks ASDQ Photomicrograph

5 Hall D Drift Chamber ElectronicsFJ Barbosa Drift Chamber Review6-8 March 2007 Block Diagram of the GlueX ASIC Prototype: The GlueX ASIC Input Protect Output Driver PreampShaperInputs Outputs Input Protection – Protects Inputs from Discharge Spikes. → Preamp - Amplifies Detector Signals with Minimal Signal Shaping. Shaper – Ion Tail is Shortened by Pole-Zero Filtering Which Improves High Rate Operation. Output Driver – Provides Drive for Signals Through Cables. N input P input The GlueX ASIC Will be Fabricated Using the 0.25 µm TSMC CMOS Process.

6 Hall D Drift Chamber ElectronicsFJ Barbosa Drift Chamber Review6-8 March 2007 Linearity is Maintained to a few % in the fC Range. Differential Output Amplitude (mV) Some Simulation Results of the GlueX ASIC Output Linearity is Within a Few % Over the Range of Interest. ENC Has Been Simulated to be Nominally 2500 e e - /pF, as a Function of Detector Capacitance.

7 Hall D Drift Chamber ElectronicsFJ Barbosa Drift Chamber Review6-8 March 2007 Input Transistors Cascodes 212um 440um Channels8 InputsTypeDual (+ and -) Impedance80 Ohm ProtectionDiode Protected C Range10-100pF ShapingPeaking Time 10pF Cin Unipolar – [CR-RC 3 ] OutputsTypeDifferential, Offset Bias Range mVp-p (-425mV to +575mV Gain2mV/fC Range0-400 fC Impulse or Point Ionization NoiseENC2500 e + 50 e/pF Power Supply +2.5V Power320 mW (40mW/Channel) Process0.25µm CMOS TSMC Die Size2.4mm x 3.2mm PackagingQFN64 10x10 mm The GlueX ASIC Summary of Specifications One Channel Layout

8 Hall D Drift Chamber ElectronicsFJ Barbosa Drift Chamber Review6-8 March 2007 Status of the GlueX ASIC Prototype: Design and Layout Have Been Completed. Design Rule Check (DRC) is Underway. Design will be Submitted to MOSIS by Middle of March. TSMC Run, Through MOSIS, on 9 April MOSIS will Perform a Final DRC Before Fab Run.

9 Hall D Drift Chamber ElectronicsFJ Barbosa Drift Chamber Review6-8 March 2007 Future Developments for the GlueX ASIC We will be testing the prototype GlueX ASIC Preamp during the Spring and Summer of What Will We Get?  1. Valuable information about the analog section on about 40 chips.  2. Validate the simulation models and the TSMC Process.  3. Verify proper operation with realistic detector conditions and adjust parameters as necessary:  Tests will be conducted on the FDC and CDC Prototypes.

10 Hall D Drift Chamber ElectronicsFJ Barbosa Drift Chamber Review6-8 March 2007 Towards the Final Design of the GlueX Preamp Design work will continue for the next year:  Shaping Control – Allows tailoring of the ASIC characteristics to various detector characteristics.  Discriminators – Will be Added to Accommodate the FDC Anodes → Lower Cost → No External Discriminators.  Gain Control – Will be Added to Accommodate the FDC Cathodes. GainShaping Amp/Disc Vth Diff. outputs ASIC Simplified Diagram of the Final GlueX ASIC ← 5 Pins Common to 8 Channels

11 Hall D Drift Chamber ElectronicsFJ Barbosa Drift Chamber Review6-8 March Preamp Cards Major Design Considerations Space Constraints Cooling Serviceability  Geometry of the Detectors, Cables, Gas Lines, Mechanical Structures.  The preamp card has to fit the FDC space requirements, which are the most severe of the wire chambers.  Cooling of any detector electronics is severely constrained due to limited space.  It is desirable to replace preamp cards with minimal down time. Standardization  It is desirable to have a single preamp architecture.

12 Hall D Drift Chamber ElectronicsFJ Barbosa Drift Chamber Review6-8 March 2007 Layout of the GlueX 24-Channel Preamp Card Input Connector (located on translator board) 50-pin Output Connector  There are two ASICs on the top side and one on the bottom side.  A supply regulator is on the bottom side. GlueX ASICInput Protection  Material is FR-4, 4-layer and 0.8 mm thick.  Components on both sides of the PCB.  The 25 th pair of pins will be used for pulse calibration. Top View  Power Dissipation = Watts

13 Hall D Drift Chamber ElectronicsFJ Barbosa Drift Chamber Review6-8 March Cabling AMPHENOL SPECTRA-STRIP 50-Conductor Cable Twisted-Pair Impedance = 90 Ohm We are considering this cable for its dimensions and electrical characteristics. FDC

14 Hall D Drift Chamber ElectronicsFJ Barbosa Drift Chamber Review6-8 March Cooling Cables are Routed Out Uniformly Over the Surface of the FDC The Four FDC Packages Are Located in This Region The FDC Has 11,520 Preamp Channels  480 Preamp Cards ►► 553 Watts. Cables are Routed Out From the CDC

15 Hall D Drift Chamber ElectronicsFJ Barbosa Drift Chamber Review6-8 March 2007 Cooling will be effected by heat conduction from the preamp cards to the cooling system. We also want to minimize convective losses to ambient air. Cooling System Barrel Calorimeter We are investigating various options as forced air is not adequate for cooling the preamp cards. Output Connector ASIC Cable 5 cm Preamp Card Input Connector Copper Braid 0.030” x 0.625” x 5” 6 mm Gap Radiator Block FDC Package (Side View)

16 Hall D Drift Chamber ElectronicsFJ Barbosa Drift Chamber Review6-8 March 2007 Temperature Profile of the GlueX Preamp Card – Simulation at Ambient Temperature of 25 ºC Still Air: ASIC Tj = 103  C Conductive Cooling: ASIC Tj = 75  C 120 ºC 40 ºC 120 ºC 40 ºC The preamp cards should not be operated without cooling provisions. Conductive cooling is effective at removing heat from the card. However, thermal performance is marginal as we would like to operate at lower Tj for improved reliability margins. An improved cooling system must be considered … … low pressure liquid cooling?

17 Hall D Drift Chamber ElectronicsFJ Barbosa Drift Chamber Review6-8 March fADCs A flash ADC is currently under development for the CDC and FDC:  72 Channels  12-bit Resolution  80 or 105 MSPS (depending on final chip selection)  Differential Inputs  2048 (19.5 μS) Acquisition Buffer  Calibration Pulsing of Detector Electronics Programmable Window and Latency. Shaping and anti-aliasing input filter for cable loss equalization and low noise. VME64X & 2eVME (~320 MByte/s). A prototype board of the frontend shaping filter is being tested with the FDC prototype.

18 Hall D Drift Chamber ElectronicsFJ Barbosa Drift Chamber Review6-8 March TDCs The F1TDC is a Multi-hit TDC developed at Jlab. VME64x Standard. 64 Channels – 115 ps rms. 32 Channels – 60 ps rms. Over 90 Modules in Use at Jlab.

19 Hall D Drift Chamber ElectronicsFJ Barbosa Drift Chamber Review6-8 March fADC Racks 1 TDC Rack 4 Racks for -HV -Low Voltage -Monitoring -Controls on Lower Level 3 Racks for -HV -Low Voltage -Monitoring -Controls 1 fADC Rack CDC FDC Cables are Shielded, Grounded & Routed to Minimize Exposure to Workers. Electronics Racks are Located Adjacent to Each of the Detectors. Platforms & Racks are Connected to Common Experiment Ground. Multiple Levels of Power Supply Current Limiting and Fusing. = Safety 8.HV, Low Voltage & Grounding

20 Hall D Drift Chamber ElectronicsFJ Barbosa Drift Chamber Review6-8 March Summary ASIC - Test the Prototype and Finalize the Design. Preamp Card - Will be Revised to Reflect the Final Design of the ASIC. Cooling System - Will be Carefully Considered Based on Cabling, the Heat Load Due to the CDC, FDC and the other Detectors. fADC - Development Will Continue Over the next Year and Prototype Tests Will be Used to Optimize the Design. TDC - Will be Modified to Accept LVDS Input Signals and To Provide Calibration Pulsing to the Detectors.