Iowa LED system for CMS HCAL

By M. Miller

Y. Onel

University of Iowa, Iowa City, IA

CMS Meeting, CERN

December 1-8, 2001

Pulser Characteristics

• Pulser located at LED • Pulser operates from +5.5 Volts and ground• Output pulse of 5.5 Volts• Circuit utilizes all bipolar devices• Rise and fall times less than 6 nanoseconds• Electrical pulse duration from 10 nanoseconds to 1

microsecond• Circuit may be easily modified to drive multiple LED’s to

achieve greater optical signal• Signal amplitude is adjusted by varying LED cathode

potential

Dual Pulser Circuit Card

1. Mounting of Circuit Card a.    Card is mounted against metal plate to increase strengthb. Existing 8-32 machine screw mounting is insufficient to support card

2. Potentiometer voltage adjustment is being used in place of analog to digital converter for testing purposes

3. Digital pulse input is two Lemo connectors rather than edge connector

4. Filtered output for reverse biasing the pin diodes @ 5 VDC is provided

5. Complete list of edge connector pins has not been provided, but +5 VDC and ground are connected

6. Circuit is being mounted as specified in “newcalibramodule” drawing

Photodiode Pulse Area vs. LED Voltage284.98

26.04

Area aveledpulsei

Area minledpulsei

Area maxledpulsei

5.21.8 V pulsei

1.8 2 2.2 2.4 2.6 2.8 3 3.2 3.4 3.6 3.8 4 4.2 4.4 4.6 4.8 5 5.220

40

60

80

100

120

140

160

180

200

220

240

260

280

300Photodiode Pulse Area vs. LED Voltage

Volts

Are

a (p

V-s

ec)

Dual Pulser Card with Filtered Output for PIN Diode

LEDOUT

Vcc

LEDOUT

Vcc

LEDCOM

POT

Bipolar Pulser with NE46134 & NE46134 Pulldown

LEDCOM

665

ZC2800

E

C

C

E

E

B

B

E

MC10EL16

NC D D̀ Vbb

Vcc Q Q` Vee

10

. 001 uF

. 001 uF

10

0

402

402 665

1 K

150

150

. 01

499

402

1000

. 001 uF

49. 9 K

4. 99 K

49. 9 . 0011049. 9

B C

E

CNEC 46134

. 001 uFZC2800

4.99

K

1 K

. 01

B C

E

CNEC 46134

FMM

T491

1 K

.001.001

10 KFM

MT491

.001

1 K

7. 68 K

49. 9

MRF

5583

665

49.9

MRF

5583

E

C

C

E

E

B

B

E

MC10EL16

NC D D̀ Vbb

Vcc Q Q` Vee

10

. 001 uF

. 001 uF

10

0

402

402

1 K

150

150

. 01

499

49. 9

402

665

1000

. 001 uF

49. 9 K

4. 99 K

49. 9 . 00110

49. 9

49. 9

B C

E

CNEC 46134

. 001 uF

4.99

K

1 K

B C

E

CNEC 46134

FMM

T491

1 K

.001.001

FMM

T491

. 001

1 K

7. 68 K

. 01

10 K

A3

A5

A7

A1

0 0

10 K

. 001

0

Pulser in Calibration Unit

Pulser in Calibration Unit

Waveform of Pulser Output

Waveform of Pulser Output (green trace) and Photodiode Signal (Blue trace)

Pulse Amplitude is 5.2 Volts.

Pulser Cards