Mercredi 18 décembre 2007

STATUS OF SPIROC measurement

Mercredi 18 décembre 2007 Ludovic Raux - SPIROC ASIC measurement 2

Reminder : Block scheme of SPIROC

Ch. 0

Ch. 1

Analog channel Analog mem.

36-channelWilkinson

ADC

Analog channel Analog mem.

Ch. 35 Analog channel Analog mem.

Bunch crossing 24 bit counterTime

digital mem.

Eventbuilder

Memorypointer

Triggercontrol

MainMemory

SRAM

Commodule

AH

CA

L SLA

B

Mercredi 18 décembre 2007 Ludovic Raux - SPIROC ASIC measurement 3

Reminder : One channel

50 -100ns

50-100ns

Gain selection

4-bit threshold adjustment

10-bit DAC

15ns

DAC output

HOLD

Slow Shaper

Slow Shaper

Fast Shaper

Time measurement

Charge measurement

TDC ramp 300ns/5

µs

12-bit Wilkinson

ADC

Trigger

Depth 16

Depth 16

Depth 16

Common to the 36 channels

8-bit DAC0-5V

Low gain Preamplifier

High gain Preamplifier

Analog memory

15pF

1.5pF

0.1pF-1.5pF

Conversion 80 µs

READ

Variable delay

0.1pF-1.5pF

IN

Discri

Gain

Flag TDC

Analog output

Mercredi 18 décembre 2007 Ludovic Raux - SPIROC ASIC measurement 4

SPIROC : tested features

• Preamplifier– Preamp disable (DC coupled channel OFF)– Gain (from 100fF to 1.5pF)– Compensation capacitances

• Slow Shaper: – different time constant : 25ns-175ns

• Auto-trigger– Trigger with 40fC observed in measurement

• Power pulsing– Programmable stage by stage

• Calibration injection capacitance• Embedded bandgap for references• Embedded DAC for trig threshold• Serial analogue output• Probe bus for debug : not yet operationnal

Mercredi 18 décembre 2007 Ludovic Raux - SPIROC ASIC measurement 5

First measurement

680fC ( ~4 pe @SiPM gain=106) in SPIROC

Charge measurement

Auto trigger

High gain channel output

Vout=30mV

Noise=1mV

Gain=45mV/pC

noise/pe~7 (expected 11)

Set up:

Cf=400fF

Tau=50ns

Mercredi 18 décembre 2007 Ludovic Raux - SPIROC ASIC measurement 6

Preampfier measurement

Vout=f(1/Cf), Qinj=680fC, tau=25ns

0

5

10

15

20

25

30

35

40

45

0 0.001 0.002 0.003 0.004 0.005 0.006

1/Cf (1/fF)

Am

pli

tud

e (m

V)

Série1

Vout=f(1/Cf), Qinj=680fC, tau=175ns

0

5

10

15

20

25

30

35

0 0.001 0.002 0.003 0.004 0.005 0.006

Amplitude Vout (mV)

1/C

f (1

/fF

)

Série1

Qinj= 680fC (~4pe at SiPM gain of 106)

Cf (fF)noise rms (mV)

tau=25ns

noise rms (mV) tau=175ns

Vout (mV) tau=25ns

Vout (mV) tau=175ns

200 1.2 2.2 42.6 32.5

400 1.0 1.3 26.3 18.7

600 0.92 1.15 18.8 13.2

800 0.9 1.0 13.9 10

1000 0.9 0.95 11.4 7.8

1200 0.9 0.9 9.6 6.6

1400 0..9 0.9 8.2 5.6

Mercredi 18 décembre 2007 Ludovic Raux - SPIROC ASIC measurement 7

Pedestal dispersion

Standard deviation :σ =1.8mVpeak-peak=8.3mV

The pedestal measurement is coherent with what we expect :-No pedestal pattern (random values according to statistical dispersion)-Statistical dispersion equivalent to what we get with that technology

pedestal

1,152

1,154

1,156

1,158

1,16

1,162

1,164

1,166

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35

Channel

DC

vo

ltag

e (V

)

Mercredi 18 décembre 2007 Ludovic Raux - SPIROC ASIC measurement 8

Input DAC linarity

0

0,5

1

1,5

2

2,5

3

3,5

4

4,5

5

0 50 100 150 200 250 300

-0,04

-0,03

-0,02

-0,01

0

0,01

0,02

0,03

0 50 100 150 200 250 300

Residuals in per cent -/+2%

Mercredi 18 décembre 2007 Ludovic Raux - SPIROC ASIC measurement 9

Conclusion

• Dynamic range• Linearity• Trigger efficiency• Crosstalk• DAC resolution (input DAC and threshold DAC)• ADC resolution• TDC resolution• Power pulsing & consumption• Digital part

.......

• Many features to be tested

• SPIROC test have started and in progress