1 Update on HV-MAPS tests Heiko Augustin July 5 , 2012
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
1
Update on HV-MAPS tests
Heiko Augustin
July 5 , 2012
2
Overview
● HV-MAPS● Setup● Characterisation● Outlook
3
HV-MAPS - Concept
● Readout logic and zerosuppression on pixel
● P-substrate + n-well● Reversly biased diode
→ Depletion → Drift → Fast collection
● Thinning: 30µm possible
4
HV-MAPS - Prototyp
● 42x36 pixel● 30x39µm²● 180nm CMOS-process● analog+digital readout● No logic on pixel● Digital part on lower chip
side● Developed by Ivan Peric
(ZITI)
5
HV-MAPS - Pixellogic
● Amplifier on the sensor
● Shaping split● Tuning via TDAC● Improved output
(no oszillations)● Possibility to improve
shaping
6
Timing parameters
7
Setup● Signal sources: blue LED, Laserdiode(855nm),
radioactive sources(Cs137, Sr90)● Injection signal used to trigger pulse generator
8
Software
● More user friendly● New features➔ ToT scan● Better saving options● Ivans new features
included➔ Fast scans and tuning
9
Characterisation - new prototyp
● HV-dependence● Pulse shape● Tuning● ToT scan● Binary Readout
10
HV-Dependence
● Same dependence as seen before
● Optimum at 80V reverse bias
● Breakdown at 90V● Begin proportional to
sqrt(HV) due to the growth of the depletion layer
11
Pulse shape
● Determination by thresholdscan of one pixel
● Measure latency and ToT
● Reconstruct the pulse shape
12
Pulse shape
● Old and new chip comparable
● No influence of comparator changing
13
Tuning-process„Old“-process
● Analog● Scan of only one pixel
at a time● Interpolation(linear)➔ Slow➔ Not always usefull
„New“-process● Digital● All pixels at the same
time● Independent of tune-
dac behaviour➔ Fast➔ Very effective➔ Large dynamic range
14
Tuning-process-VPDAC
● Dynamic range selectable
● Not linear behaviour
15
Tuning results
„OLD“
„NEW“
16
Tuning results - ToT scan
„untuned“
„tuned“
17
Jitter
● Jitter for LED bigger then for Laser● Sensor-Jitter measurement with LED
Jitter(untuned): ~100nsJitter(tuned): ~65ns (but this can be improved)
18
Binary readout - Pattern
● Waiting for rising edge of comparator
● Possibility to take out the border pixels
● Planned to determine the sensor-jitter
19
Binary readout - Delay influence
20
Binary readout - Sr90
21
Binary readout - Sr90-tuning
● Tuning with injection pulse
● Difficult● Needs time
22
Beamtest @ timepix
Telescope needed:● Spatial resolution● Time resolution
Beamline needed:● Efficiency● MIP Signal + X-Talk● Size of clusters
23
Summary
● HV-up to 80V possible and optimal
● Doublepulse resolution: ~3.2µs
● Jitter(pix): ~8ns● Jitter(chip): ~65ns
but can be improved
24
Outlook
Coming up:● Timepix beamtest in
August● PSI-Praktikum
August/September
Sensor To do list:● Getting the uxibo
ready for the beamtest
● New Submission in July
● Effective jitter-measurement
● Particle tuning
25
Backup - ToTscan+Tuning
26
Pulse shape
Puls shape depends on:HV, signal amplitute, timing parameters, position on the sensor
27
MAPS - Logic
Related Documents
