Liverpool BeO Forward Hybrid with 12 x ABCDs


Preliminary Results

A Liverpool BeO Forward Hybrid has been populated  with 6 x ABCD-N to both sides (12 x ABCDs in total to be readout).
The hybrid and ABCDs addressing format is as follows: All results presented are with Edge Detect enabled and using Edge Data Compression.
40MHz clock mark-space ratio set to 1:1.
Nominal values of  VCC = 3.5V and VDD =  4.0V (measured on hybrid).
 
Initial results have been obtained with the front-end bias set for the low and high current biasing.
Threshold was scanned from 0mV - 625mV in 2.5mV steps, injected charge was from 1fC to 4fC in steps of 0.5fC.
The results shown are for injected charges of 2fC, 3fC and 4fC in Postscript format.

Results
Low current operating region
Injected Charge (fC)
Noise (fC)
Gain (mV/fC)
Threshold (mV)
2
Noisel2.ps 
Gainl2.ps 
Thresl2.ps 
3
Noisel3.ps 
Gainl3.ps 
Thresl3.ps 
4
Noisel4.ps 
Gainl4.ps 
Thresl4.ps 

 
High current operating region
Injected Charge (fC)
Noise (fC)
Gain (mV/fC)
Threshold (mV)
2
Noiseh2.ps 
Gainh2.ps 
Thresh2.ps 
3
Noiseh3.ps 
Gainh3.ps 
Thresh3.ps 
4
Noiseh4.ps 
Gainh4.ps 
Thresh4.ps 
 
Chip Parameters (Low current operating region)
Parameter
M0
S1
S2
S3
S4
S5
S8
S9
S10
S11
S12
E13
Front-end bias (uA)
73.6
73.6
64.4
73.6
73.6
73.6
64.4
73.6
73.6
73.6
73.6
73.6
Front-end shaper (uA)
18
18
18
18
18
18
18
18
16
16
14
14
Strobe delay (bits)
23
23
23
23
23
23
23
23
23
23
23
23
 
Chip Parameters (High current operating region)
Parameter
M0
S1
S2
S3
S4
S5
S8
S9
S10
S11
S12
E13
Front-end bias (uA)
220.8
211.6
202.4
211.6
211.6
211.6
193.2
211.6
211.6
211.6
211.6
211.6
Front-end shaper (uA)
18
16.8
18
21.6
18
16.8
16.8
18
19.2
16.8
16.8
19.2
Strobe delay (bits)
27
27
27
25
27
27
27
27
27
27
29
27
 
Summary When operating in the high current region there is increased sensitivity to the chips bias settings, as more chips are turned 'on' this can modify the bias settings of those chips already biased. It thus becomes an iterative process of checking chip performance as more chips are turned 'on' and then maybe having to modify the bias settings on those chips which had already been configured with optimum bias settings.

The Forward Hybrid with 12 x ABCDs has been readout successfully with no obvious degradation in performance when compared to results obtained with a Hybrid with 6 x ABCDs.
 



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Last modified: 29/10/98