1. PID meeting SNATS to SCATS New front end design
Introduction to Integration
Christophe Beigbeder PID meeting
May

2. Christophe Beigbeder PID meeting
New documents available
Christophe Beigbeder PID meeting
May

3. Christophe Beigbeder PID meeting
SCATS
Instantaneous
Dead time ~25ns
Readout dead time
Output Max speed~20 MHz
Push the data
Christophe Beigbeder PID meeting
May

4. Christophe Beigbeder PID meeting
Performances
Already measured : Resolution , Linearity … => SNATS matches our requirements.
Expected :
Dead time at the input : 25 ns. Matches the background input max frequency with a a large safety factor
Readout :
Number of data words per event
Readout frequency per channel (All channels fired) ,25 MHz ,5 MHz MHz
Max readout frequency per channel (only one channel fired) MHz MHz MHz
Match the 70ns and 150 KHz Trigger requirements.
The complete chain up to the sector concentrator has to mach the
4 us trigger latency.
Christophe Beigbeder PID meeting
May

5. Christophe Beigbeder PID meeting
Electronics faces 2 goals :
process the PM signals with
FeChip/TDC/ADC .
Concentrate and pack channel data and send it to the DAQ
Electronics on the detector
Mechanical constraints.
Thermal constraints
Power distribution issues including HV.
Cables and links
Christophe Beigbeder PID meeting
May

6. Christophe Beigbeder PID meeting
First idea : small boards assembled in module ( a la G Warner )
Nice modularity : failure, debug
Task well identified between Frontend and data processing.
Difficult to mount and dismount on the detector.
A lot of cables .
-> Proposal for a crate-
like solution for
Fblock electronics
Christophe Beigbeder PID meeting
May

7. Christophe Beigbeder PID meeting
Fblock electronics
All boards are guided like in a crate with rails. Permits to mount/dismount them in any case needed.
We copy a crate structure. From price concern we use commercial components : bars , rails … -> gives some constraints on our design on size and assembly.
PMs alignment constraints : PM footprints have to be aligned vertically and horizontally with a precision which has to be similar to that of commercial crates.
The pitch (board to board space ) is half than in a standard crate => no connector on front panels.
Christophe Beigbeder PID meeting
May

8. Christophe Beigbeder PID meeting
PM footprints used as a backplane.
Backplane covering all PMs including
extra row connectors for signals distribution.
Fblocks
Custom backplane for boards
interconnection.
Very good grounding and shielding
HV distribution can also be foreseen.
Christophe Beigbeder PID meeting
May

9. Christophe Beigbeder PID meeting
Fe Crate
Christophe Beigbeder PID meeting
May

10. Data flow consideration
TDC (16 channels ) : 16 + Chan Add + Charge …
-> 32 bits per 80 MHz.
-> 6 rows -> Bus of 192 bits entering one ( 2 ? ) FEPGA
housing L1 buffer.
150 kHz Trigger / 32 bit data per event
-> 5 kbits per pixel
5 k * 16 pixels * 6 PM rows
-> ~ 5 Mbits per board on backplane.
Christophe Beigbeder PID meeting
May

11. Requirements on fan trays and heat exchanger.
A rough estimation gives :
Fe : 500 mW / 16 Channels
PGA : 1 W / 16 channels
TDC : 500 mW / 16 channels
`+ glue => Total 3 W / 16 channels.
=> Sector ( ~ 3kchannels ) = ~ 600 W ( 350 W on Babar/~600 ch)
=> Less than 8 kW in total.
From Wiener data sheet
Q = ( 3.1 P) / T
Q= airflow in m3 / h
P = Dissipated power ( W)
T = Temperature change at given air flow
-> 1kW power , a specified difference T = 10 degrees requires a airflow of 300 m3/h 0
Christophe Beigbeder PID meeting
May