FP420Low and high voltage supply

Henning E. Larsen,

INFN

Henning.e.larsen@gmail.com

Dec. 2006. rev.2

Revision information

• Since I made the slides, the frontend has gone from 6 to 4 detectors/superlayer. I have as far as possible tried to take this fact into account in this revised version.

HV-LV supply segmentation

Damage depends on distance from the beam. Required bias voltage and current increase with radiation dose.

Drawing: From Ray Thompson

PT1000 Temperature sensor?

Pixels:50x400um and 400x50um

MCC: Module Controller Chip

1 Superlayer =

2 Hybrids/Blades4 2D detectors1 MCC1 Read-out interface

Now only 2 det.

Specification for LV for 1 superlayer

PixChips/4 Voltage Current Current limit

Analog 1.6-2.0VNom 2V

5-70mA 100mA

Digital 1.5-2.5VNom 2V

1% occupancy: 40-50mA 10% occupancy: 60-70mA

100mA

MCC/1 Voltage Current Current limit

Digital 1.8-2.5V 120mA-150mA 170mA

Ripple at 1MHz is critical. Remote on/off. Monitor current.Digital supply for Pixelchip and MCC is common as seen from supply.

4 PixChips + 1 MCC

+ Read-out?

Voltage Current Current limit

Analog 1.6-2.0V 20-280mA 310mA

Digital 1.8-2.5V 1% occ 280mA-350mA

10% occ 360mA-430mA

480mA

Monitor resolution <20mV <10mA

DEC 2006:Notice change from 6 to 4 detectors per superlayer

Specification for HV supply

4 detectors

2 voltages

Voltage Current Current limit

-10-150V

0-120V(*)

<1mA 1mA

Monitor

Resolution

<1V 1μA Voltage is negative, but floating.

Referenced to AVDD on PIXELCHIP, not GND

HV connection diagram used in Atlas

Source: Maurice Garcia-Sciveres

DEC 2006:

Notice change from 6 to 4 detectors per superlayer

(*) -120V is also sufficient.

One of 4 stations

Counting inventory:

Super layers: 2 experiments * 2 zones * 5 pockets * 5 superlayers=100 super layers

LV supplies: 100 super layers * 2 voltages = 200 channels

HV supplies: 100 super layers *2 voltages = 200 channels

Crate count is preliminary

Overall system geography

Commercial: Wiener solution A

• 2x4 Mpod-like systems (8U,19” each) will be arranged to provide the requested voltages over 500 m distance,

• Located in the counting rooms and will host both HV and LV modules. • 2 cable pipes with 10 cm section (or probably less) are needed. • The Mpod will require custom -150V modules. .

4*2 Mpods with 80ch each.

Location: Counting room

Mpod

x 8

•150k€ for Mpod’s

•100k€ for cables

Now only 2 HVNow only 2 HV

Commercial: Wiener solution B

• 2x10 Maraton-like radiation tolerant systems (3U) will provide LV and operate close to the detectors.

• 2x2 Mpod-like devices will supply HV from the counting rooms.

• This solution requires a customization of Maraton in order to optimize it for low currents.

• The Mpod will require custom -150V modules.

• Cost not yet discussed.

One per pocketMpod

x 2 x 5

One per pocketOne per crystat

1 Maraton 1 Maraton

Now only 2 HV

Commercial: Wiener solution C

• 2x22 Maraton-like system will provide HV and LV and operate close to the detectors.

• Simple cable • These systems will be optimized for the given current range. • Need customization for -150V modules• Proven radition tolerance: 722Gy, 8 1012n/cm2

• Cost not yet discussed

1 Maraton

2.2 crates per pocket

H=3U=131mm

1 Maraton

2.2 crates per pocket

x 11x 11

Now only 2 HV

CMS/Atlas counting room

Commercial: Caen

SY1527

A1676A

Crate Ctl

A1676A

Crate Ctl

A3486

2x48V

Power

A3486

2x48V

Power

Atlas or CMS

Slow control

EASY 3000

A3009

12ch

LV

A3009

12ch

LV

A3009

12ch

LV

A3009

12ch

LV

A3009

12ch

LV

EASY 3000

A3501

12ch

HV

A3501

12ch

HV

A3501

12ch

HV

A3501

12ch

HV

A3501

12ch

HV

A3501

12ch

HV

A3501

12ch

HV

FP420

pocket

FP420

pocket

FP420

pocket

FP420

pocket

FP420

pocket

LHC Tunnel

EASY 3000

A3009

12ch

LV

A3009

12ch

LV

A3009

12ch

LV

A3009

12ch

LV

A3009

12ch

LV

EASY 3000

A3501

12ch

HV

A3501

12ch

HV

A3501

12ch

HV

A3501

12ch

HV

A3501

12ch

HV

A3501

12ch

HV

A3501

12ch

HV

FP420

pocket

FP420

pocket

FP420

pocket

FP420

pocket

FP420

pocket

Cryostat 1 Cryostat 2

Commercial: Caen, pictures

SY1527EASY 3000

Not to scale

A3009 A3501

Commercial: Caen

A3009 LV

A3501 HV

A3009 LV

A3501 HV

A3486 48V Power

•Modules 220k€

•Cable ~20k€

•Delivery not possible before summer 2008 due to LHC production bottle neck. Only few samples by mid 2007.

•CAN bus link has to be extended to 500m. This is not yet tested

•High voltage only up to 120V

Cable:500m

Commercial: Eplax GmbH

• Entirely custom design based on their >20year experience with standard power supplies and our specification

• No experience with radiation tolerant supplies.

• Non recurring engineering cost: 25k€• Supply for 1 superlayer: 900€• Total cost: 115k€ (excl cables)

LV supply: simulation model with long lines

•Current transients are mainly limited by capacity at the load.

•Simulation shows a 500m+500m cable with 20% current change for C=1µ, 5µ, 50µF

Conclusion:

•500m++ of LV cables is not feasible

Simulation, Low voltage, 500m cable

LV supply using LHC4913

If we make our own custom solution a regulator like LHC4913 is very convenient and unique. It is now being ported to a military/space qualification => higher cost, but presumably available.

1. Rad hard.

2. Extensively used at LHC detectors.

3. Remote sense on the positive and negative supply. This means it can compensate for resistive cable voltage drop. This means that with LHC4913, a thinner cable can be used.

4. Adjustable current limit.

5. ON/off switch input.

ADC’s: DCUF Detector Control Unit (CMS)

•CMS central tracker for the monitoring of some embedded parameters like supply voltage and currents on the front-end read-out modules•Is available in the quantity we need

HV principle diagram

+

Vbias

-

Cable

VinαIbias

αVbias

Ibias

Transformer+rectifier

R3

R2

R1R1

R2

Passtransistor

DAC

•Simple linear regulator to make radiation tolerance easier to implement with COTS

•Monitor, remote control, galvanic isaolated

Galvanicisolation

ADC’s

“Home made” in-tunnel-solution

cost estimate

Modules 120k€

Cable 20k€

Item unit cost Units in total

LV-HV boards

PCB 150 €Components 300 €Mechanics 30 €Connectors 70 €Mounting 150 €

Total 700 €120 700 € = 84,000 €

CrateBackplane 300 €Connectors 100 €Mechanics 200 €

Total 600 €24 600 € = 14,400 €

Crate controllerPCB 150 €Components 300 €Mechanics 30 €Connectors 70 €Mounting 150 €

Total 700 €24 700 € = 16,800 €

Cables

? ?

Total cost 115,200 €

Total cost CMS+ATLAS 120,000 €

?? To be figured out but much much less than solution with

# Pcs+ 20%spar

Location for service electronicsUntil today we thought:• If the LV electronics should stay within some 20m from the detectors, there are only two possible locations (ref

Daniela Macina):

– Below the new cryostat, where the radiation level is estimated at about 700 Gy per year of running at full luminosity;

– Below or near the adjacent magnets, where the radiation is much lower and estimated at about 15 Gy per year, but where there are already other things.

Space for service electronics.•Few meters of cable•Radiation level?•Shielding possibility?

Space for electronics needing close proximity to detectors

At mechanics meeting 29/9/06 we saw:

FP420 detectors

Issues to finalize• Location of support electronics in tunnel. Favour of putting it under the

adjacent magnets. Cable length about 10m.

• Radiation level to expect. There ought to be simulations done with shielded cryostat at fp420 to evaluate the dose. Current assumption is 15GY/y

• Home made or commercial solution?

• Cable distances from fp420 to the counting room for all 4 stations have to be estimated more precisely than the current 500m

• Specification of number of channels

• Specification of LV supply for superlayer readout part (Opto board).

• Need for temperature monitor of FE for the cooling system. Where should it be serviced? If in the HV-LV unit, we need define a local interface with cooling as this cant go through slow control.

• Are there any requirement for:

– Hardware interlocks related to temperature?

– Graceful power down =UPS backup?

Conclusions

• Some interesting solutions from industry. Some almost off the shelf.

• We have an outline of how to build the LV-HV our selves but chip supply is critical.

• We need to make up our minds if we buy or build ourselves.

• We are opting for putting the LV/HV crates under the adjacent magnets