1. VELO upgrade Front-end ECS LHCb upgrade electronics meeting 12 April 2012 Martin van Beuzekom on behalf of the VELO upgrade group Some thoughts, nothing definite yet

2. 2 VELO upgrade options: Strips and Pixels  Front-end chips are being designed for both a strip and pixel options  We have 21-26 stations depending on option  1 station = 2 modules, on both sides of beam  Strips: double sided module: 20 FE chips per side (R/Phi) 2 halves * 21 stations * 2 sides (R/Phi) * 20 chips = 1680 chips, 128 channels each  Pixels: “single” sided module: 12 FE chips 2 halves * 26 stations * 12 chips = 624 chips, 65k pixels each  In the following I will show the pixel option because it is more demanding in terms of configuration data 40M pixels versus 256k strips because I know it better VELO upgrade ECS, April 12, 2012Martin van Beuzekom2

3. Pixel module  12 readout ASICs: VELOpix 4 sensor modules (units), 3 chips each  Readout + ECS ‘tape’ either per ASIC, or per 3 ASICS?  Up to 12.2 Gbit/s data from hottest chip -> equivalent to 4*GBT Tx VELO upgrade ECS, April 12, 2012Martin van Beuzekom3

4. Where thing are / hopefully will be VELO upgrade ECS, April 12, 2012Martin van Beuzekom4 repeater boards hybrid control +temp. boards D3 balcony LV + HV DAQ ECS (specs/can) TFC 15 meter copper 1 meter copper new ‘repeater’ boards hybrid D3 LV + HV DAQ TFC + ECS via GBT <1 meter copper Current scheme Upgrade scheme where to put the GBTs, and how many vacuumair

5. Where things are (II)  Electrical Optical conversion always outside of vacuum tank  Where to put the ECS/TFC GBTs, in vacuum or outside ?  How many ECS/TFC GBTs do we need  Non negligible amount of radiation On flange: 1 Mrad/ 10 years (t.b.c.) in vacuum: up to 100 Mrad (strongly depends on position)  Power dissipation in vacuum should be minimized  But number of electrical connections (feedthroughs) also  Seems attractive to move the ECS/TFC GBT to the hybrids (vacuum)  ‘Repeater’ board houses all others functions Electrical optical (for ECS/TFC GBT and for DAQ) LV regulators + sensing/monitoring Temperature sensing FPGA for glue-logic? radiation? do we need it? VELO upgrade ECS, April 12, 2012Martin van Beuzekom5

6. option1: GBT+SCA outside vacuum tank + 1 ECS/TFC GBT for 6 VELOpix chips -> 104 ECS/TFC GBT for whole VELO + Less power dissipation in vacuum + Accessible + All monitoring functions in one place via SCA - Need low jitter clock transmission for high speed serial links in VELOpix - Need many signals on kapton tape (20-25 per 6 VELOpix chips) VELO upgrade ECS, April 12, 2012Martin van Beuzekom6 e/o hybrid new ‘repeater’ < 1 m. copper SCA GBT 20-25

7. Option 2: GBT+SCA on hybrid  Electrical -> Optical conversion on air side  Copper link at 4.8 Gbit/s to GBT chip vacuum tank first tests give very good results  1 GBT for 3 VELOpix chips (maybe 6) individual clock per VELOpix available (low jitter) common TFC signals configuration via GBT e-link (being discussed) SCA for monitoring of voltage, temperature etc.  Requires extra power in vacuum: VELOpix = 6x(2-3)W, GBT+SCA= 2W?  Additional ECS GBT needed for monitoring temp, power on ‘repeater’ ~10% extra GBTs VELO upgrade ECS, April 12, 2012Martin van Beuzekom7 SCA GBT e/o hybrid new ‘repeater’ < 1 m. copper

8. Issues that need further study  Configuration speed Assume ~1 Mbit of configuration data per ASIC -> ~600 Mbit for the whole VELO Detailed study of data flow (# of GBT masters etc.) to be done  Configuration protocol SPI-like, I2C ? trade-off: speed vs complexity  How to handle the chip calibration (threshold equalization) requires (long) sequence of set mask scan threshold and take data Will take almost forever with standard PVSS stepping mechanism -> Add specific features to VELOpix to speed up this process VELO upgrade ECS, April 12, 2012Martin van Beuzekom8

9. BACK-UP SLIDES VELO upgrade ECS, April 12, 2012Martin van Beuzekom9

10. VELOpix scratch-page  Signals: Clock, low jitter Reset, Bcreset (T0), Testpulse Enable slow control: SC-data-in, SC-data-out 4 DAQ links at >3.2 Gbit/s effectively 8 links at lower speed? extra TFC inputs? analog output?  Use the simple (robust) SC interface proposed for the TPX3? can be controlled directly from GBT requires uninterrupted stream of ~500-800k bits in ‘one shot’ VELO upgrade ECS, April 12, 2012Martin van Beuzekom10