MPPC readout electoronics

M.Taguchi(kyoto)

MPPC readout with DAQ board

DAQ boardOUT_P

OUT_N

-+

OPAMP

Trip-t

+5V

-5V

4m flat cable

Labview

control signal

trig

gain=1MPPC

LED

LabviewDAQ board

trig

Trip-t

MUX_CLK MUX_CLK

timingを合わせる

MUX_CLK from DAQ board

MUX_CLK from Labview

A_OUT from Trip-t (test charge)

Trip-t

OPAMPDAQ cable

ADC distribution(test charge)

ADC count

Trip-t A_OUT gain

pipeline

1pF

3pF

preamp gain x1 or x4

pipeline gain x2,x4,x8…

preamp

charge

A_OUT of MPPC

preamp gain=x4 pipeline gain=x1

ADC distribution

preamp gain=x4

pipeline gain=x1

not same

400pixel V=70.0V

A_OUT Linearity

preamp gain=x4, pipeline gain=x1

preamp gain=x4, pipeline gain=x2

•low signal linearity problem associates with this version of chip

preamp gain=x1, pipeline gain=x4

MPPC 10p.e. (G=7.5x105)

A_OUT of MPPCpreamp gain=x1,

pipeline gain=x4

ADC distribution(2)

preamp gain=x1

pipeline gain=x4

same

400pixel V=70.0V

MPPC gain measured by Trip-t and CAMAC

by CAMACby Trip-t

•400pixel

•100pixel

1x106

3x106

4x105

1x106

crosstalk of A_OUT

0.4%

• 1.4pC to ch15 (Dynamic range of Trip-t with this gain setting)

• crosstalk~0.4%

ch

•preamp gain=x1,

pipeline gain=x4

• 70.0V

readout 4MPPCs simultaneously

100pix 400pix

400pix 400pix

Problem?

• LED trig

PRE_RST

MPPC signal after preamp

LED trig

V=69.8VV=71.4V

•Strange pedestal structure due to charge up on coupling capacitor when bias V up

Problem?V=71.4V

Trip-t

signal

charge on capacitor

V=69.8V

Problem?V=71.4V

•at the bias V we see strange pedestal, raw signal is also strange

no problem

backup

• There is no special change if we change the values of registers

- preamp feedback control - preamp drive current - etc…• now design the board of 32ch MPPC

inputs

A_OUT gain

• preamp gain = x1 pipeline gain= x4• variation ~4%

ch Gain (ADC count/pC)

15 730

16 710

31 735

32 732

T_OUT

charge

Disc_OUT

PIPE_CLK

time difference

voltage

T_OUT linearity

time(ns) time(ns)

•input charge=0.65pC

T_OUT gain

• variation~25%ch Gain (count/ns)

15 8.52

16 8.60

31 8.00

32 9.97

Disc. threshold curve

• propability of discri firing

5Vth unit = 2.5fC ~ 0.02p.e.

threshold uncertainty

•input charge =0.13pC

Time walk

• T_OUT ADC count vs injected charge

• time walk

position dependence of PIPE_CLK

preamp out

PIPE_CLK

time(ns)