First results from First results from PADI-2PADI-2

Mircea CiobanuMircea Ciobanu

CBM Collaboration Meeting CBM Collaboration Meeting

March 10 –13, 2009March 10 –13, 2009

GSI-DarmstadtGSI-Darmstadt

FEE1

OutlineOutline

Status of the RPC-Front End Electronics Status of the RPC-Front End Electronics

First results of the PADI2First results of the PADI2 (4ch)(4ch) prototype:prototype: a) Gain, linearity, noise, bandwidth, time over threshold behaviora) Gain, linearity, noise, bandwidth, time over threshold behavior

b) Timing performanceb) Timing performance

c) Measurements with the TACQUILA3 digitizerc) Measurements with the TACQUILA3 digitizer

d) Crosstalk, Common Mode Rejection Ratiod) Crosstalk, Common Mode Rejection Ratio

e) Input impedance and reflectionse) Input impedance and reflections

Summary and OutlookSummary and Outlook

FEE Status (February 2009)FEE Status (February 2009)

1.1. We have prepared 6 PADI1 test plates for tests together with different We have prepared 6 PADI1 test plates for tests together with different detectors. In order to have a easy access to NIM-CAMAC systems, 6 detectors. In order to have a easy access to NIM-CAMAC systems, 6 interfaces LVDS-PECL are ready for use.interfaces LVDS-PECL are ready for use.

2.2. From the tests of PADI1 prototype, we have recognized that the increase of From the tests of PADI1 prototype, we have recognized that the increase of the separation between channels is the main priority. In the new design of the separation between channels is the main priority. In the new design of PADI2 we have changed the biasing type from voltage to current. We have PADI2 we have changed the biasing type from voltage to current. We have increased to 4 the number of channels and we have added the OR feature increased to 4 the number of channels and we have added the OR feature which allows to daisy-chain chips for trigger purposes. We have designed two which allows to daisy-chain chips for trigger purposes. We have designed two variants PADI2 and PADI3 which slightly differ in output LVDS levels.variants PADI2 and PADI3 which slightly differ in output LVDS levels.

3.3. The new ASIC – PADI2,3 was submitted in October 2008 and we have The new ASIC – PADI2,3 was submitted in October 2008 and we have received about 30 pcs. dies.received about 30 pcs. dies.

4.4. With the first two samples we performed a basic functionality tests. From this With the first two samples we performed a basic functionality tests. From this elementary tests we can conclude that elementary tests we can conclude that all channels are fully operational.

5.5. We have designed a test PCB, which is able to be We have designed a test PCB, which is able to be directly connected with our TACQUILA3 Data Acquisition system and the first results will be Data Acquisition system and the first results will be presented.presented.

6.6. We started a detailed technical characterization of the first samples and first We started a detailed technical characterization of the first samples and first results will be presented.results will be presented.

PADI1 Test PCB and the LVDS-ECL adaptor PADI1 Test PCB and the LVDS-ECL adaptor PCBPCB

PADI2 Preamplifier-Discriminator: Block PADI2 Preamplifier-Discriminator: Block SchematicSchematic

NEWSNEWS

PADI2 is bonded directly on the test PCBPADI2 is bonded directly on the test PCB

PADI2,3 Test PCBPADI2,3 Test PCB

DC Measurements 1: IDC Measurements 1: IDCDC chip and chip and Power/Channel dependence to RPower/Channel dependence to REXTEXT

20 40 60 80 100 120 14020

30

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I DC

Chi

p[m

A]

REXT

[]

Pow

er

/Ch

ann

el[m

W]

Nominal Operating PointNominal Operating Point

for Zfor ZININ=50=50

DC Measurements 2: DC Measurements 2:

0 5 10 15 200

50

100

150

200

250

B 12.593mV/V

A 1.2 mV

VT

HR

Ch

ip[m

V]

VTHR-EXT

[V]

PADI2 #1, #2Test PCB

Linear Fit:

-0.7

-0.6

-0.5

-0.4

-0.3

-0.2

-0.1

0.0

P2#1-1P2#1-2P2#1-3P2#1-4P2#2-1P2#2-2P2#2-3P2#2-4

Line

arF

itS

lope

[V/V

]

IDC

26mA 36mA 46mA 56mA -8

-7

-6

-5

-4

-3

-2

-1

0

1

2

3

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7

Lin

ea

rF

itIn

terc

ep

t[m

V]

P2#1-1P2#1-2P2#1-3P2#1-4P2#2-1P2#2-2P2#2-3P2#2-4

IDC

26mA 36mA 46mA 56mA

0 50 100 150 200 250

-120

-100

-80

-60

-40

-20

0

VT

HR-E

OU

T[m

V]

VTHR

-Chip [mV]

26mA36mA46mA56mA

Linearity: Pulse MeasurementLinearity: Pulse Measurement

-30 -20 -10 0 10 20 30-400

-300

-200

-100

0

100

200

300

400

56mA

46mA26mA

36mA

Eo

ut_D

iff[m

Vpk

]

Uinp [mVpk]

Ch1Ch2Ch3Ch4

IDC-chip

26mA

-10mV Linear Fit 10mV

PADI2#1

0

5

10

15 Ch1Ch2Ch3Ch4

Lin

ea

rF

itS

lop

e[V

/V]

56mA46mA36mA26mA

IDC-chip

0.0

0.5

1.0

1.5

2.0 Ch1Ch2Ch3Ch4

Lin

ear

Fit

Offs

et[m

V]

56mA46mA36mA26mA

IDC-chip

Time over Threshold behaviorTime over Threshold behavior

1 10 100 1000

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

6.5

7.0

Ch1Ch2Ch3Ch4

Pu

lse

wid

th[n

s]

Uinp [mV]

VTHR

-chip [mV]

26 52 102 152 202 253

PADI2#1; AC Transmission MeasurementPADI2#1; AC Transmission Measurement

1E7 1E8 1E90

5

10

15

20

25

30

IDC-chip=66mA

Eo

ut-

Gai

n[d

B]

Frequency [Hz]

1P (Disc. to Q. Buffer)1N (Disc. to Q. Buffer)2P2N3P3N4P4N

-3dB

fH=72MHz

PADI2#1 Ch.1-4

Gain=27dB

1E7 1E8 1E9-20

-10

0

10

20

30

fH=20MHz f

H=72MHz

-3dB

PADI2#1-Ch.1

Gain~28dB

Eo

ut-

Gai

n[d

B]

Frequency [Hz]

26mA36mA46mA56mA66mA

IDC-chip

(Disc. to Q. Buffer)

1E7 1E8 1E9

-60

-55

-50

-45

-40

-35

-30

-25

-20

-15

-10

-5

0PADI1#9-Ch1

fL=14MHz f

H=190MHz

Gain=(60-20)dB=40dB

Eo

ut-

Ga

in[d

B]

Frequency [Hz]

40dB50dB60dB70dB80dB

The nominal working point of the PADI2-PA: The nominal working point of the PADI2-PA:

GGPAPA=38.8dB, f=38.8dB, fLL=2.8MHz, f=2.8MHz, fHH=288MHz=288MHz

with par.:with par.: GGPAPAP=37.8dBP=37.8dB fL=2.4MHz, fL=2.4MHz,

fH=215MHzfH=215MHz

at EOut: at EOut: GGEOEO=34.5dB=34.5dB ffLL=2.8MHz, f=2.8MHz, fHH=230MHz=230MHz

with par.:with par.: GGEOEOP=31.8dBP=31.8dB ffLL=2.4MHz, f=2.4MHz, fHH=203MHz=203MHz

ffHH is about 4 times less then PADI1 case! For is about 4 times less then PADI1 case! For

what?what?

PADI1PADI1

PADI2PADI2

PA-Out Simulations: CornersPA-Out Simulations: Corners

0.0 500.0M 1.0G10

15

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40

1234567891011121314151617181920

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37383940414243444546 47 48 49 50

5152

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ABCDEFGHIJKLMNOPQRSTU

V

W

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AB

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AD

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AF

AG

AH

AI

AJ

AKALAMANAOAPAQARASAT AU AV AW

AXAY

AZ

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BC

BD

BE

BF

BG

BH

abcdefghijklmnopqrst

u

v

w

x

y

z

aa

ab

ac

ad

ae

af

ag

ah

ai

aj

akalamanaoapaqaras at au av aw

axay

az

ba

bb

bc

bd

be

bf

bg

bh

EffEfnspEsnfpEssEttEresminEresmaxEmcminEmcmaxE1V6M20E1V630E1V680E1V8M20E1V830E1V880E2V0M20

1 E2V030A E2V080a E09

E11

Ga

in[d

B]

Frequency [Hz]1k 10k 100k 1M 10M 100M 1G

10

15

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35

40

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 1819

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A B C D E F G H I J K L M N O P Q RS

T

U

V

W

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Z

AA

AB

AC

AD

AE

AF

AG

AH

AI

AJ

AKAL

AMAN AO AP AQ AR AS AT AU AV AW

AXAY

AZ

BA

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BC

BD

BE

BF

BG

BH

a b c d e f g h i j k l m n o p q rs

t

u

v

w

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aa

ab

ac

ad

ae

af

ag

ah

ai

aj

akal

am an ao ap aq ar as at au av awax

ayaz

ba

bb

bc

bd

be

bf

bg

bh

Ga

in[d

B]

Frequency [Hz]

EffEfnspEsnfpEssEttEresminEresmaxEmcminEmcmaxE1V6M20E1V630E1V680E1V8M20E1V830E1V880E2V0M20

1 E2V030A E2V080a E09

E11

260.0M 280.0M 300.0M65

70

75

80

85

90

95

100

105

PA

-Ou

tGai

n[A

.U.]

Frequency [Hz]

ttfffnspsnfpssc-minc-maxr-minr-max

240.0M 260.0M18

20

22

24

26

ttfffnspsnfpssc-minc-maxr-minr-max

EO

utG

ain

[A.U

.]

Frequency [Hz]

Nominal working pointNominal working point

GGPAPA=87=87

BW=288MHzBW=288MHz

GGEOEO=23=23

BW=255MHzBW=255MHz

EOut Simulations:EOut Simulations:Parasitic, CornersParasitic, Corners

and nonlinear Loadand nonlinear Load

0.0 2.0p 4.0p 6.0p 8.0p 10.0p

12

14

16

18

20

200600100014001800

EO

utG

ain

[A.U

.]

CL

[F]

0.0 2.0p 4.0p 6.0p 8.0p 10.0p120.0M

140.0M

160.0M

180.0M

200.0M

220.0M

EO

utB

and

wid

th[H

z]

CL[F]

200600100014001800

240.0M 260.0M18

20

22

24

26

ttfffnspsnfpssc-minc-maxr-minr-max

EO

utG

ain

[A.U

.]

Frequency [Hz]

RL is nonlinear : The input impedance of the RL is nonlinear : The input impedance of the PCB Q-Buffer is strong nonlinear (1KPCB Q-Buffer is strong nonlinear (1K--100 100 ) and depends of frequency ) and depends of frequency

CL is significant: 4-6pF for PCB traces and 1-CL is significant: 4-6pF for PCB traces and 1-3pF for bonding wires.3pF for bonding wires.

RLRL

RLRL

Nom.Op.PointNom.Op.Point

GPA=23GPA=23

BW=255MHzBW=255MHz

Noise evaluationsNoise evaluations

From PADI2 Noise simulations:From PADI2 Noise simulations:

GainGain Noise at outputNoise at output Noise at inputNoise at input Noise equiv.Noise equiv.

PAPA 86.986.9 2.14mV2.14mVRMSRMS 24.6µV24.6µVRMSRMS3400 e3400 e

PA with Parasitic PA with Parasitic 78.278.2 2.07mV2.07mVRMSRMS 26.5µV26.5µVRMSRMS3780 e3780 e

4

5

6

7

8

9

10

11

SD 0.605Mean 10.09

SD 0.623Mean 9.315

SD 0.628Mean 7.441

PADI2#2Ch1 Ch2 Ch3 Ch4

No

ise

atQ

Ou

t[m

VR

MS]

26mA36mA46mA56mA

Ch1 Ch2 Ch3 Ch4

PADI2#1

SD 0.375Mean 4.485

IDC-chip

Time resolution for different threshold Time resolution for different threshold voltagesvoltages

(tests with pulses having 1.7ns at HM)(tests with pulses having 1.7ns at HM)

1 10 100 10001

10

100

PADI - 2, #1, Ch1

t[p

s]

Uinp [mV]

14 mV27 mV51 mV77 mV102 mV127 mV

0.1 1 10 100 10001

10

100

PADI - 2, #2, Ch1, Pasive Probe

t[p

s]

Uinp [mV]

7mV14mV26mV52mV102mV152mV202mV253mV

Channel EOut Offset = +2mVChannel EOut Offset = +2mVChannel EOut Offset = -3.2mVChannel EOut Offset = -3.2mV

Comparison: Comparison: PADI2 and TACQUILA3 versus PADI1 and TACQUILA3PADI2 and TACQUILA3 versus PADI1 and TACQUILA3

@ 02.2009@ 02.2009

(pulse width(pulse width - 4ns!)- 4ns!)

@ 02.2007@ 02.2007

1 10 100 10001

10

100

PADI #1 ,#2 and TACQUILA3, at differents VthrOne channel Timing Resolution

Sig

ma

[p

s]

Uinp [mV]

#1;198 mV 98 mV 66 mV #2;198 mV 98 mV 66 mV

1 10 1001

10

100

#1, 30mV60mV120mV240mV355mV

#2, 30mV60mV120mV240mV362mV

PADI2#1,#2, Ch1-Ch2, IDC=46mA

One Channel Timing resolution

T[p

s]

Uinp [mV]

VTHR

-chip

Input Reflections: Short Pulse Method Input Reflections: Short Pulse Method

Uinp=10mV,Uinp=10mV,

Refl=+/-3%Refl=+/-3%

-30dB-30dB -6dB-6dB

-6dB-6dB

YY

SyncSync

TDSTDS

71047104

AttenuatorAttenuatorDirectionalDirectional

BridgeBridge

HP8721AHP8721AD.U.TD.U.T

-6dB-6dB

PulsePulse

Gen.Gen.

HP8082AHP8082ASplitterSplitter

ZZii=47=47- 53- 53

Cal: Open, 7.48mVCal: Open, 7.48mVIIDCDC=26mA, 3.1mV=26mA, 3.1mV

36mA, 2.2mV36mA, 2.2mV

46mA, 1.1mV46mA, 1.1mV

56mA, 0.25mV56mA, 0.25mV

25 30 35 40 45 50 55 60 65

40

50

60

70

80

90

100

110

120

130

ZIN

[]

IDC

[mA]

Y = A + B1*X + B2*X^2

A 229.41912B1 -5.01354B2 0.03237

50

56mA

Polinomial Fit

PADI2#1-Ch.1

Crosstalk:Crosstalk: Short Pulse Short Pulse

Measurement Measurementat Qoutputat Qoutput

0.0

0.1

0.2

0.3

0.4

0.5

121314212324313234414243

Lin

ea

rF

itS

lop

e[V

/V]

0.1 1 10 100 10001

10

100

1000CTRR

nmmax=20logG

nn/G

nm=20log(138.8/0.06)=67.3dB

CTRRnm

min=20logGnn

/Gnm

=20log(138.8/0.52)=48.5dB

Qo

ut[m

V]

Uinp [mV]

11121314212223243132333441424344

PADI2#1, VTHR

-chip=50mV, IDC

=46mA

0

10

20

30

40

50

60

70

Lin

ea

rF

itIn

terc

ep

t[m

V]

121314212324313234414243

CMRR: Short Pulse MeasurementCMRR: Short Pulse Measurement

1 10 100

10

100

1000

Qou

t[m

Vpk

-pk]

Uinp [mVpk]

Ch1Ch2Ch3Ch4

-88.9 -59.2 -57.3 -114.74.37 4.95 6.56 10.06

AB

Linear Fit (x>5mV)

CMRR=20log(GD/G

CM) [dB]

GD=138.8

GCM

=4.37 - 10.06

CMRR=22.3 - 30 dBPADI2#1

1 10 100

10

100

1000

Qou

t[m

Vpk

-pk]

Uinp [mVpk]

Ch1Ch2Ch3Ch4

-86.4 5.8 7.3 2.55.3 1.0 0.9 0.3

AB

Linear Fit (x>5mV)

CMRR=20log(GD/G

CM) [dB]

GD=138.8

GCM

=0.3 - 5.3

CMRR=28.3 - 53.3 dBPADI2#1

-6dB-6dB

-6dB-6dB

PulsePulse

Gen.Gen.

HP8082AHP8082A-30dB-30dB

AttenuatorAttenuator

Power SplitterPower Splitter

To Ch.+INTo Ch.+IN

To Ch.-INTo Ch.-IN

2ns Lemo cables:2ns Lemo cables:

l ~ 220mml ~ 220mm non equals length non equals length

Lemo cables:Lemo cables:

l ~ 3.5mm matchedl ~ 3.5mm matched

for for max. CMRR-Ch4max. CMRR-Ch4

SummarySummary

- The PADI2 design was successful - The PADI2 design was successful tested. alltested. all channelschannels are operationalare operational..

-- PADI2 in connection of with our TAQUILA3 Data Acquisition systemworks properly.

- The first results indicate:

Time res.(@10mV) [ps] < 10 Gain ~ 80 ? Bandwidth [MHz] ~ 220 ? Linear range [mV] ~ -10 to

10 CTRR [dB] > 40 CMRR [dB] > 28 Input impedance [] ~ 47 - 53 Power [mW/Ch] ~ 25

OutlookOutlook

The DC measurements showsThe DC measurements shows a big dispersion of the DC offsets at the output of the PA for different channels(+/-7mV). Probably is due to the low open loop gain of the feedback loop and of the non good match of the involved stages. Can be corrected?

In crosstalk measurements was pointed out a influence of the digital part to the analog one; the ground connections inside the chip must be reevaluated.

Tests of PADI1-2 with different RPC

detectors must be done. . The analog outputs are more The analog outputs are more

needed?needed? Connection with the GSI event-driven

TDC GET4 prototype must evaluated.

We acknowledge the support of the European We acknowledge the support of the European Community- Community-

Research Infrastructure Activity under the FP6 Research Infrastructure Activity under the FP6

"Structuring the European "Structuring the European Research Area" programme Research Area" programme (HadronPhysics, contract number RII3-CT-2004-506078).(HadronPhysics, contract number RII3-CT-2004-506078).

Q CalibrationQ Calibration

1E7 1E8 1E9

-60

-55

-50

-45

-40

-35

-30

-25

-20

-15

-10

-5

0

-80dB

-70dB

-60dB

-50dB

Q calibration

Qou

t[d

B]

Frequency [Hz]

IDC-chip=61mA

PADI2#1 Ch.1-4

Gain=(70-26)dB=44dB

fH=93MHz

-3dB

1E7 1E8 1E9-65

-60

-55

-50

-45

-40

-35

-30

-25

-20

-15

-10

-5

0

Gain=(40-23)dB=17dB

-50dB

-40dB

Qou

t[d

B]

Frequency [Hz]

Gain=(40-19)dB=21dB

E to Q Test Buffer calibration

-30dB

IDC-chip=61mA

PADI2#1 Ch.1-4

Crosstalk: Short PulseCrosstalk: Short Pulse Measurement Measurement

at Eoutputat Eoutput

1 10 100 1000

1

10

100

Eo

ut[

mV

]

Uinp [mV]

Ch1Ch2Ch3Ch4

-0.178mV 15.75V/V

Linear Fit 1-10mV

PADI2#1

1 10 100 1000

1

10

Eo

ut[

mV

]Uinp [mV]

121314212324313234414243

MAX. SLOPE=0.061 [V/V]

CTRRnm

=20logGnn

/Gnm

=20log(15.75/0.061)=48.2dB

?

PADI2#1

0

1

2

3

4

5

6

7

8

9

121314212324313234414243

Lin

ea

rF

itIn

terc

ep

t[m

V]

0.00

0.01

0.02

0.03

0.04

0.05

0.06

121314212324313234414243

Lin

ea

rF

itS

lop

e[V

/V]

Comparison: The time resolution of all designsComparison: The time resolution of all designs

1 10 100 10001

10

100

FEE-NINO#4, Ch9

Sig

ma

[p

s]

Uinp [mV]

42 mV 101 mV 200 mV 275 mV

1 10 100 10001

10

100

FEE5 #10, Ch2

Sig

ma

[p

s]

Uinp [mV]

40mV 80mV 120mV 185mV

1 10 100 10001

10

100

FEE1 #30, Ch4, GAIN~100

Sig

ma

[ps]

Uinp [mV]

-19mV -36mV -55mV -98mV

1 10 100 10001

10

100

PADI #2, Ch3

Sig

ma

[ps]

Uinp [mV]

58 mV 86 mV 113 mV 141 mV 196 mV 251 mV