Oct, 2000 CMS Tracker Electr onics 1 APV25s1 STATUS ting started beginning September afer cut, others left for probing chips mounted on test boards 9 work well all I2C registers read/writeable no obvious pipeline defects (run with pseudo-random trigger after single reset) pulse shape OK for one channel 1 chip with obvious analogue problem 1 channel pedestal stuck high and low gain in others ailed results here confined to few chips so far line formance of S1 chip version (early results) Pulse shape, linearity, noise, pipeline uniformity, radiation tests clusions Mark Raymond [email protected]
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Oct, 2000CMS Tracker Electronics1 APV25s1 STATUS Testing started beginning September 1 wafer cut, others left for probing 10 chips mounted on test boards.
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Oct, 2000 CMS Tracker Electronics 1
APV25s1 STATUS
Testing started beginning September1 wafer cut, others left for probing10 chips mounted on test boards 9 work well all I2C registers read/writeable no obvious pipeline defects (run with pseudo-random trigger after single reset) pulse shape OK for one channel
1 chip with obvious analogue problem 1 channel pedestal stuck high and low gain in others
Detailed results here confined to few chips so far
Outline
Performance of S1 chip version (early results)Pulse shape, linearity, noise,pipeline uniformity, radiation tests
reticule consists of 4 APVs1 APVMUX/PLLtest structures
Oct, 2000 CMS Tracker Electronics 4
APV25s1 layout
7.1
mm
8.1 mm
design changes input edge layout changes to reduce track resistance
(input pad layout changed) calibration capacitor layout improved gain increased (resistor values at mux input stage) added internal master current reference for bias generator
(backend pad layout changed from s0 version) digital bug in pipeline logic fixed minor tweaks to component values to achieve greater margins for operation (shaper feedback resistance)
Oct, 2000 CMS Tracker Electronics 5
Analogue part of data frame software reordered
Output data frame
Raw data frame
Actual channel order
Samples at 50 nsec. intervals
-4
-2
0
2
4
-4
-2
0
2
4
Digital header1 mip
Cur
rent
[m
A]
differential current output (+ve o/p only shown above)
nominal (mid-range) gain now 1.2 mA/mipvariable between 0.8 and 1.5 in 5 steps
Oct, 2000 CMS Tracker Electronics 6
APV25s1 biasing
internal/external option determined by 2 pads (IREF & IREFBIAS)
Measure for every channel, take rms value, convert to electronsand histogram
freq
uenc
y
rms electrons
No significant noise contribution
20
15
10
5
01501251007550250
peak mode deconvolution
Oct, 2000 CMS Tracker Electronics 13
Pipeline – gain uniformity
How well do pipeline capacitors match?Signal retrieved as charge so mismatch => gain dependence onpipeline capacitance
Measure by storing/retrieving signal to/from every cell
ADC units
freq
uenc
y
Very good matching between pipeline cells
50
40
30
20
10
0150100500
192 entriesmean 122.7sd 0.86min 120.6max 125.7
Oct, 2000 CMS Tracker Electronics 14
AD
C u
nits
time [nsec.]
before after 10 Mrads
Radiation tests
1chip irradiated to 10 Mrads using 50 kV X-rays
500400300200100
0250200150100500
500400300200100
0250200150100500
3.02.52.01.51.00.50.0
Noise – histogram all channels
after 10 Mrads
before
Almost no observable degradation after 10 Mrads (confirmsresults from s0 run)
rms ADC units
minor retuning of pulse shape required after irradiation
peak mode deconvolution
Oct, 2000 CMS Tracker Electronics 15
Probe testing plans for APV25s1
New probe card made (only needs active and decouplingcomponents to be added) similar (functionally) to s0 version except multiple (3) probes for power on front edge 1 amplifier input probed allowing true chip gain to be determined
Additions to test software measure pulse height for probed channel test multi-mode operation sweep one bias setting measuring power supply currents
Tested die should be available early November
Oct, 2000 CMS Tracker Electronics 16
APVMUX/PLL status
Oct, 2000 CMS Tracker Electronics 17
ConclusionsEarly APV25s1 results indicate good performance consistentwith results from APV25s0. Minor problems fixed.