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ABC130 Bus Tape Width – A first look. Layout assumptions Powering scheme is Serial, ‘chain of modules’. Believe this scheme will be the first to become available Power traces designed to carry 4A 3 A/module plus 1A overhead (sufficient?) Assuming ~150mA/ asic (worst case)
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ABC130 Bus Tape Width – A first look • Layout assumptions • Powering scheme is Serial, ‘chain of modules’. • Believe this scheme will be the first to become available • Power traces designed to carry 4A • 3A/module plus 1A overhead (sufficient?) • Assuming ~150mA/asic (worst case) • Serial Power Protection (SPP) will require 4(?) traces • Common Bus to all modules • SPP will be located on sensor • Stave HV, provided by Axon cable, has 4 HV + 1 Common Return (5 traces total), 3 scenarios: • HV lines to 4 ‘groups’ of modules (3/3/3/4) with common return • Will look at this one first of all • HV and HV offsetting to 2 ‘groups (6/7) with common return • Single HV and HV offsetting to ALL modules with common return • Use Tape Design Rules as on present Stave250 – reference manufacturers ‘Altaflex’ specification • 100µm Track and Gap (minimum) • Minimum cover layer opening 50µm • Current design maintains 500µm clearance from features, smallest comes in at 0.8mm x 0.8mm • HV spacing, exposed pads: 1.75mm, under cover layer: 0.8mm • Trace to tape edge distance: 1mm
Bus Tapes for ABC130 – Detail • Proposed Stave topology – layout is flipped compared to Stave250 (w.r.t. Power/HV and digital buses) • Look at ‘Module 0’ only – has the highest density of tracking (sets stave width) EOS Module Power and HV Module 0 Module 12 Hybrid Hybrid Hybrid Hybrid Hybrid Hybrid Hybrid Hybrid Hybrid Hybrid Hybrid Hybrid Hybrid Hybrid Hybrid Hybrid Hybrid Hybrid Hybrid Hybrid Hybrid Hybrid Hybrid Hybrid Hybrid Hybrid SPP SPP SPP SPP SPP SPP SPP SPP SPP SPP SPP SPP SPP TTC and Data Bus • TTC bus made up of: • BCStave, L0_CMD and R3_L1 • (3 x Diff Pairs) • 2 X Data Outs per module (Diff Pairs) • (duplicated at the hybrid for redundancy) • 100µm Track and Gap HCC HCC Hybrid Data 1 Hybrid Data 0 Module TTC 4.2mm Tape Edge 1.75mm Wire bonds 1mm
Bus Tapes for ABC130 – Detail Tape Edge Filtered HV to Sensor Raw HV and Return Raw HV and Return HV3 HV2 HV1 8.6mm HV0 HVret SPP Control bus SP to neighbouring module SP In SP Return 8mm • Serial Power Trace is 8mm wide, designed to carry 4A (18µm Cu thickness) • SP Return length ~1400mm, Trace Resistance ~ 180mΩ • Power dissipation ~ 2.9W (~220mW/module location) with a Vdrop of ~720mV
Conclusion... • Based on the Stave250 layout geometry, the tape width is coming in at 110.34mm (~112mm?) • cf Sensor Geometry + tape widths for routing (97.54mm + 4.2mm + 8.6mm = 110.34mm) • But • Based on current Stave250 layout design rules • Smallest cut outs are currently 0.8mm x 0.8mm (small red square shown below) • Distances shown by red arrows have to be >1.75mm to maintain exposed HV clearances • Moving to new design rules results in a cut out geometry of 3.1mm x 3.1mm • Shown by the larger red square • Possible that the tape might have to go wider to accommodate these larger cut outs whilst maintaining HV clearances