Chamber PCB s, FEB s, Cooling, HV/LV Distribution

1) PCB designs-track widths, track to track distances …

2) Double sided and Multi layer, modular approach.

3) Resistors for protection against possible sparks.

4) Orientation of FEB s, Scheme, Cooling

5) HV/LV distribution- No of channels, Modules, cost

Prototype PCBs

No of pads- 256, Pad sizes-8*3.4 sq mmReadout area-97*85 Sq mm. Read by 2 FEBs each with 128 channels.2 types of pad sizes tried. Both Staggered. Double sided PCB

Track widths -6milTrack- track – 6 mil to 15mil.Resistors added later (0603)

Top copper

256 tracks - all on bottom copper

For previous test beams

vias from- top to bottom copper

For next Test beam

Resistors -0402

3 and 4 sq mm pads. Not staggered.

Track lengths are long.

4 mil tracks. Track- track 4 /6 mil spacing Cross talk??? Multi layer with GND planes???

512 pads- to be read by 4 FEBs each 128 channels

Double sided PCB- all 512 tracks on bottom copper only

Bottom copper

Top copper

Pad area-67*73 Sq mm for 3mm. For 4mm - 88*97 sq mm

4 layer PCB with GND PlaneTop copper

Inner 1

Inner 2

Bottom copper

Connectors for FEBsConnector with resistors

Type 1

GND Plane

GND plane

GND Plane

4 layer PCB with GND tracks

Bottom copper

Inner 1

Every track is in between 2 GND tracks.

in case of type2 Too many tracks to draw. Easy to draw the GND planes in case of type1. Removal of planes is also easier

Track lengths are still very long due to connectors for both cases.

Type-2

Top and Inner-2 not shown.

Modular approachInner 1 Inner-2 Bottom Copper 2.6 Sq mm Pads

32*8 matrix. 256 pads Single 300 pin Connector. Reads 2 n - XYTERS.

Top copper

Blind vias from inner layers( blue)

Blind vias (red ) to inner layer

2.6 mm square pads

Pads arranged in one block of 32*8=256.

Connected to 300 pin connector.

Tracks - shorter and not closer . can be easily duplicated for bigger sizes. 4 such blocks for GEM of 10cm * 10 cm.

Each block read by 1 FEB with 2 n-XYTERs

No resistors could be added so far.

FEBs can be mounted horizontal or vertical

For STAR PMD

For ALICE PMD

Prototype design

Inner1

Inner2

Bottom copper

Top copper

4 connectors. Each reads 2 N-XYTERS.

44 spare pins on the connector.

FEB--Probable scheme??

64 channel chip-- No of Pin outs 125-150?

For inputs- 64 For I2c - 6For CLK - 6For SDA, SCl - 2I2C Reset - 2Reset 2 DATA (diffl) --- 18 ( 16 for digital, 2 analog)

Total -100 PLUS Bias ,GND, other control inputs -25 to 50 ??

Consider

BGA144(1,27mm pitch) / SQFP148(10*14)

with 148 pin count and if we arrange-see the board size-10cm*3.2cm

BGA-144

ADC

300 Pin CON

SQFP148

ADC

ROC CON

Cooling Issues

FEB with one NXYTER draws 1.5A @5V.(with regulators)

For a 2 chip FEB , Current drawn is expected to be 3A minimum. Power= 15Watts. With 3.3V it is 10 Watts.

With 4 such FEBs, each reading a zone with 1K pads, the power dissipation is 40 Watts on an area of 10(cm) * 10 (cm).

Same as power dissipated on one ALICE-PMD module (4608 cells).

Each FEB with 2/4 n –XYTERS needs cooling. To be taken care while designing the FEB.

Detector specifications

Detector active area= 20 sq met. GEM PCB dimensions= 30x30Cm. No Of GEMS required =20 ÷0.3x0.3= 222.2= 222

Total number of GEMs required = 222x3= 666 (for triple GEM).

9k pads on one chamber PCB (30cm by 30 cm) For 500,000 we need 56 Nos, each for chamber and drift PCBs (min).

HV

HV channels required for GEM PCBs = 222 ( one for each triple GEM)

HV specification = 3 to 5 KV/1mA /5Watts.

CAEN 1535 board has 24 HV channels. Each = 3.5KV/3mA. SHV /multi pin connectors.CAENA1550-5KV/1mA with multi Pin and SHV

Can be housed in SY1527. Number of boards required will be = 10 ( 10x24=240 channels).

SY 1527 houses 5/10 boards. Need 2/1 Crates. Power consumption= 240x5Watts = 1.2KW

Detector, HV

FEBs-LV FEB s, ROC s

Channels to read= 500,000

One N-XYTER reads =128 channels. FEB with 2 n-XYTERS reads-256 channels

No of FEB s Required = 500,000÷256 = 2000 No (512,000 channels).

Each ROC can handle = 2 FEBs (512 channels). No Of ROCs required =1000Nos.

LV Specifications

2chip Feb With 3.3 v supply the power dissipation =10watts.

2000 FEBs consume =2000x 10Watts =20KW.

One ROC need -3.5A @5V ( one FEB connected). With two FEBs it is 4A

1000 ROC s consume = 1000x5Vx4A=20KW.

Power consumption expected for 2000FEBs +1000 ROCs = 40KW

A3009B -2to 8 V, 9A @5V. Max =45W. Has 12 independent channels. Max 480Watts

For 1000 ROCS Need 1000÷12= 84 modules

For 2000 FEBSs = 2000÷12= 167 modules. Need 167+84 =251 modules. Separate LV channels for FEB and ROC. Alternately:

Reduce LV channels to 168÷2=84 by using LVDB to feed 2 FEBS (from 1 channel)

Need 84+84 =168 modules.

No of 3009s in one EASY crate =4 (2KW)

EASY crates Required = 250÷4=63 or 164 ÷4=41

With 2 channels 3486 has =48V /40A , Power Capacity =5KW

3486 s required = 40KW÷5 = 8Nos. Filter for 3486 =8 Nos. One Branch Controller (A1676A) controls 6 EASY- 3000 Crates.

For 63/41 Crates we need = 11 /7 Branch controllers

.

LV distribution

Costs of CAEN-LV/HV modules

• SY1527 -Universal Crate-- 11K Euro• 3486-48V supply- 12K Euro• A3000NF-Filter for 3486--- 3.2KEuro• A1676- Branch Controller --- 1.4K Euro• A3009B--- 2 to 8V supply ----- 7.1K Euro• EASY 3000 Crate (for A3009B)---- 2.6K Euro• A1535-24 channel HV module---- 4.8K Euro• A1550 -24 Channel HV module---------- 5.8K Euro

Issues to be taken care

Too many modules and Crates ???

Alternate systems from WEINER or ??

Which Detector Control System PVSS or ??? Cooling system - water cooled or air cooled??

FEB PCB vertical type of horizontal type ???

If No regulators on the FEB, any precaution to be taken in DB…..????