Transient Waveform Recording
Utilizing TARGET7 ASIC
J. Zhang, S. Liu*, Y. Wang, C. Yang, X. Zhu, C. Feng
University of Science and Technology of China
Presented by Yu-Wang(Nick)
University of Science and Technology of China
Signal In Real World and Computer
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Analog signal in real world
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Digital signal in computer
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Such as sounds
Hard to store and process
Computer only know 0 and 1
Easy to store
Computer can process
Convert analog signal to digital signal
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2017/7/13
Need an element: ADC(Analog-Digital Convertor)
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Technology In Particle Detector
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Traditional way
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Advanced way
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Cannot get the waveform
Record the amplitude of the signal
Record the waveform using fast ADC
Only record one waveform in one chip
Our new way
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2017/7/13
Record 16 waveform in one chip
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TARGET-7 ASIC
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ASIC(Application-Specific Integrated Circuit)
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An integrated circuit (IC) customized for a
particular use
TARGET-7
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2017/7/13
An IC designed for high-speed and multi-channel
particle detector
16 input channels
Can convert 100 billion signal in one second
Just as big as a coin
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Detail of TARGET-7
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2017/7/13
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Design of the Test-Board
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Use FPGA to Control as Master
FPGA:
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CPU like element,
Can process multiple task at one time
Structure of Test-Board
Signal
Control
2.5V
RFin_1
RFN_1
100nF
50Ω
Other
inputs
similarly
SSTin
WLCLK
TARGET7
Dout[15:0]
buffer
RFin_16
RFN_16
Contorl
VrampRef
LVDS
LVDS
16
Data
Command
SSTin
WLCLK
FPGA
Data
200pF
DAC
LTC2614
2017/7/13
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DC(Direct Current) Transfer Function
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Relation Between Signal and Data
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ADC counts is a function of input signal
Result
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2017/7/13
Linear voltage:0.5~1.8V
552 to 3785 ADC counts
11.6-bits resolution
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Voltage Calibration
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2017/7/13
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Voltage Calibration
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Result
Before
calibration
After
calibration
2017/7/13
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AC(Alternating current) Performance
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AC Transfer Function
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2017/7/13
Using sinusoidal signals as input
Linear in low amplitude(<0.6V)
AC saturation happens in high amplitude(>0.6V)
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Application in Charge Measurement
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Charge Measurement
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Most important information
Recording charge waveform
Measurement method
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2017/7/13
Use CSA(Charge Sensitive Amplifier) and shaper
to collect charge
Compared with Oscilloscope
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Application in Charge Measurement
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Result
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2017/7/13
Nonlinearity of TARGET7 is 0.6%
Better than oscilloscope 0.1%
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Conclusion1
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We have designed a 16-channel 1GSPS
waveform digitizer with TARGET7 ASIC
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2017/7/13
The dynamic range is 1.8V
DC noise is 1.76mV
After DC calibration, nonlinearity is 1.1%
Timing resolution is 152ps
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Conclision2
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We have applied the TARGET-7 to charge
measurement
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2017/7/13
The waveform record is better than the same
speed Oscilloscope
The nonlinearity of charge measurement is 0.6%
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Future Work
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Some experiments needs millions of
channels, and Target-7 ASIC is an optimal
option.
We need to test other ASIC as well as
Target-7
New calibration methods are under
investigation
2017/7/13
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