VITESSE VSC7939W, VSC7939RP Datasheet

VITESSE

SEMICONDUCTOR CORPORATION

Preliminary Data Sheet

VSC7939

Laser Diode Driver with Automatic Power Control

SONET/SDH 3.125Gb/s

Features Applications

• Power Supply: 3.3V or 5V ±5%

• AC-Coupled to Laser Diode

• Programmable Modulation Current: 5mA to 60mA

• Programmable Bias Current: 1mA to 100mA

• Enable /Disable Control

• Typical Rise/Fall Times of 60ps

• Automatic Optical Average Power Control

• Supply Current of 33mA at 3.3V

• SONET/SDH at 622Mb/s, 1.244Gb/s,

2.488Gb/s, 3.125Gb/s

• Full-Speed Fibre Channel (1.062Gb/s)

General Description

The VSC7939 is a single 3.3V or 5V supply l aser diode driv er special ly desig ned for S ONET/SDH appli cations up to 3.125Gb/s. External resistors set a wide range of bias and modulation currents for driving the laser. Data and clock inputs accept differential PECL signals. The autom atic power control (APC) loop maintains a constant average optical power over temperature and lifetime. The dominant pole of the APC loop can be controlled with an external capacitor. Other features include enable/disable control, short-circuit protection for the modulation and bias inputs, short rise and fall times, programmable slow-start circuit to set laser turn-on delay, and failure-monitor output to indicate when the APC loop is unable to maintain the average optical power. The VSC7939 is available in die form or in a 32-pin TQFP package.

Block Diagram

V

P

L

C

D

P

L

V

CC

BIASMON

CC

C

F

R

F

V

CC

1nF

3.3V Operation

LATCH

IOUT+ IOUT-

MUX

DATA+

DATA-

CLK+

CLK-

ENABLE

DISABLE

G52350-0, Rev 3.2 Page 1 02/26/01

SET

D

Q

CLR

APC

MODSET

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BIASMAX

Internet: www.vitesse.com

CAPC

APCSET

V

MODMON

MD

FAIL

BIAS

CC

VITESSE

SEMICONDUCTOR CORPORATION

SONET/SDH 3.125Gb/s

Preliminary Data Sheet

Laser Diode Driver with Automatic Power Control

Electrical Characteristics

Table 1: AC Specifications

AC specifications are guaranteed by design an d characterization. Typical values are for 3.3V.

Symbol Parameter Min Typ Max Units Conditions

t

SU

t

H

t

R

t

F

PWD Pulse Width Distortion 10 50 ps See Notes 1, 2 CID

t

J

NOTES: (1) Measured with 622Mb/s 0-1 pattern , LATCH=high. (2) P WD = (wi der pulse - narrower pulse) / 2).

Input Latch Setup Time 100 ps LATCH=high Input Latch Hold Time 100 ps LATCH=high Enable/Start-up Delay 250 ns Output Rise Time 60 80 ps 20% to 80% Output Fall Time 60 80 ps 20% to 80%

Maximum Consecu tive Identical D igits 80 bits

MAX

Jitter Generation 7 20 ps

p-p

Jitter BW=12kHz to 20MHz, 0-1 pattern.

VSC7939

Table 2: DC Specifications

Symbol Parameter Min Typ Max Units Conditions

I

CC

I

BIAS

I

BIAS-OFF

S

BIAS

VR

MD

I

MD

I

MOD

I

MOD-OFF

R

Supply Current TBD 45 mA

Bias Current Range 1 100 mA Voltage at BIAS pin=(VCC-1.6)

Bias Off Current 100 µA

Bias Current Stability

Bias Current Absolute Accuracy ±15 % Refers to part-to-part variation Monitor Diode Reverse Bias Voltage 1.5 V Monitor Diode Reverse Current Range 18 1000 µA

Monitor Diode Bias Setpoint Stability

Monitor Diode Bias Absolute Accuracy -15 15 % Refers to part-to-part variation Modulation Curren t Rang e 5 60 mA

Modulation Off Cu rr ent 200 µA

-480 -50 480

230 900 APC open loop. I

90 IMD=18µA

ppm/°C

R I

BIAS

V

ENABLE=low or DISABLE=high

APC open loop. I

I

MD

ENABLE=low or DISABLE=high

MODSET BIASMAX

and I

=5V

CC

=1mA

=7.3kΩ

=4.8kΩ

MOD

(2)

excluded

(1)

BIAS BIAS

(1)

=100mA =1mA

Page 2 G52350-0, Rev 3.2

Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: prodinfo@vitesse.com

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02/26/01

VITESSE

SEMICONDUCTOR CORPORATION

Preliminary Data Sheet

VSC7939

Laser Diode Driver with Automatic Power Control

SONET/SDH 3.125Gb/s

Symbol Parameter Min Typ Max Units Conditions

Modulation Current Absolute Accuracy ±15 % See Note 2

Modulation Current Stability

A

BIAS

A

MOD

NOTES: (1) Both I

BIASMON to I MODMON to I

tion does not change with temperature.

BIAS

and I

-480 -50 480 250 I

Gain 37 A/A I

BIAS

Gain 29 A/A I

MON

will turn off if any of the current set pins are grounded. (2) Assume s l ase r di ode t o monitor diode transfer func-

MOD

ppm/°C

I

=60mA

MOD

=5mA

MOD BIAS/IBIASMON MOD/IMODMON

Table 3: PECL and TTL/CMOS Inputs and Outputs Specifications

Symbol Parameter Min Typ Max Units Conditions

V

ID

V

ICM

I

IN

V

IH

V

IL

Differential Input Voltage 100 1600 mV

-

V

Common-Mode Input V oltage

Clock and Data Input Current -1 10 µA TTL Input High Voltage

(ENABLE, LATCH) TTL Input Low Voltage

(ENABLE, LATCH)

TTL Output High Voltage (FAIL

TTL Output Low Vo ltage (FAIL

)2.4

) 0.1 0.44 V Sinking 100µA

CC

1.49

2.0 V

VCC -

1.32

V

0.3

CC

-

VCC V

/4

ID

0.8 V

V

CC

V PECL-compatible

V Sourcin g 50µA

(DATA+)-(DATA-)

p-p

G52350-0, Rev 3.2 Page 3 02/26/01

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Internet: www.vitesse.com

VITESSE

SEMICONDUCTOR CORPORATION

SONET/SDH 3.125Gb/s Laser Diode Driver with Automatic Power Control

Absolute Maximum Ratings

Power Supply Voltage (VCC).............................................................................................................-0.5V to +7V

Current into BIAS.....................................................................................................................-20mA to +150mA

Current into OUT+, OUT-...............................................................................................................................TBD

Current into MD.............................................................................................................................-5mA to +5mA

Current into FAIL

Voltage at DATA+, DATA-, CLK+, CLK-, ENABLE, LATCH.........................................-0.5V to (V

Voltage at APCFILT, MODSET, BIASMAX, APCSET, MD, FAIL

Voltage at OUT+, OUT-..................................................................................................... -0.5V to (V

Voltage at BIAS..................................................................................................................-0.5V to (V

Continouous Power Dissipation (T

Operating Junction Temperature Range...................................................................................... -55°C to +150°C

Storage Temperature Range ........................................................................................................ -65 °C to +165°C

NOTE: (1) CAUTION: Stresses listed under “Absolute Maximum Ratings” may be applied to devices one at a time without caus-

ing permanent damage. Functionality at or above the values listed is not implied. Exposure to these values for extended periods may affect device reliability.

......................................................................................................................... -10mA to 30mA

= +85°C, TQFP derate 20.8mW/°C above +85°C) .......................1350mW

A

(1)

.............................................-0.5V to +3.0V

Preliminary Data Sheet

VSC7939

CC

CC CC

+ 0.5V)

+ 1.5V) + 0.5V)

Recommended Operating Conditions

Positive Voltage Rail (VCC).....................................................................................................+3.135V to +5.25V

Negative Voltage Rail (GND) ............................................................................................................................0V

Modulation Current (I Ambient Temperature Range (T

NOTE: (1) VCC = 3.3V, I

MOD

BIAS

(1)

)

.......................................................................................................................30mA

).................................................................................................-40°C to +85°C

A

= 60mA.

Page 4 G52350-0, Rev 3.2

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Internet: www.vitesse.com

02/26/01

VITESSE

SEMICONDUCTOR CORPORATION

Preliminary Data Sheet

VSC7939

Bare Die Pad Descriptions

Pad 10

Pad 12

GND1

Pad 13 LATCH

Pad 14 ENABLE

Pad 15

DISABLE

Pad 16

GND1

Pad 17

BIASMON

Pad 11

VCC1

(Pin 7)

(Pin 8)

(Pin 9)

(Pin 10)

(Pin 11)

CLK-

Laser Diode Driver with Automatic Power Control

Figure 1: Pad Assignments

1773

µm (0.0698")

Pad 9 CLK+

Pad 8 VCC1

Pad 7 GND1

Pad 6 VCC1

Pad 5 DATA-

Pad 4

DATA+

SONET/SDH 3.125Gb/s

Pad 3

VCC1

(Pin 1)(Pin 2)(Pin 3)(Pin 4)(Pin 5)(Pin 6)

Pad 2

GND1

(Pin 32)

(Pin 31)

(Pin 30)

(Pin 29)

Pad 1 GND2

Pad 48

VCC2

Pad 47

BIASMAX

Pad 46

MODSET

Pad 45

GND2

Pad 44

APCSET

20

µm

(0.0008")

2233

µm

(0.0879")

Pad 18

(Pin 12)

MODMON

Pad 19

FAIL

Pad 20

GND4

Pad 21

PB_GND

Pad 22

APCFILT

Pad 23

GND4

Pad 24

VCC4

Pad 25

BIAS

(Pin 13)

(Pin 14)

(Pin 15)

(Pin 16)

(Pin 17)

Pad 26

PB_GND1

(Pin 18) (Pin 19) (Pin 20) (Pin 21) (Pin 22) (Pin 23) (Pin 24)

Pad 27

VCC4

Pad 28

DB_OUT+

Pad 29

OUT+

VSC7939

Pad 30

OUT-

Pad 31

DB_OUT-

Die Size: 1773µm x 2233µm (0.0698" x 0.0879") Die Thickness: 625

µm (0.0246")

Pad Pitch: 115µm (0.0045") Pad Size: 95µm x 95µm (0.0037" x 0.0037")

Pad to Pad Clearance: 20µm (0.0008

") Pad Passivation Opening: 95µm x 95µm (0.0037" x 0.0037") Scribe Size: 75µm (0.0030")

Pad 32

VCC4

Pad 33 GND4

Pad 34

GND3

(Pin 28)

(Pin 27)

(Pin 26)

(Pin 25)

Pad 35

MD

Pad 43

RESERVED

Pad 42

GND3

Pad 41

PB_GND

Pad 40

GND3

Pad 39

PB_GND

Pad 38

CAPC

Pad 37

VCC3

Pad 36

GND3

75

(0.0030")

µm

G52350-0, Rev 3.2 Page 5 02/26/01

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Internet: www.vitesse.com

VITESSE

SEMICONDUCTOR CORPORATION

SONET/SDH 3.125Gb/s Laser Diode Driver with Automatic Power Control

Table 4: Pad Coordinates

Signal Name

GND2 1 1613.55 1863.475 BIAS 25 (Pin 17) 159.45 368.475 GND1 2 1414.525 2073.55 PB_GND 26 369.525 159.45 VCC1 3 (Pin 1) 1289.525 2073.55 VCC4 27 (Pin 18) 484.525 159.45 DATA+ 4 (Pin 2) 1174.525 2073.55 DB_OUT+ 28 599.525 159.45 DATA- 5 (Pin 3) 1059.525 2073.55 OUT+ 29 (Pin 19 ) 714.525 159.45 VCC1 6 (Pin 4) 944.525 2073.55 OUT– 30 (Pin 20) 829.525 159.45 GND1 7 829.525 2073.55 DB_OUT– 31 944.525 159.45 VCC1 8 714.525 2073.55 VCC4 32 (Pin 21) 1059.525 159.45 CLK+ 9 (Pin 5) 599.525 2073.55 GND4 33 (Pin 22) 1174.525 159.45 CLK- 10 (Pin 6) 484.525 2073.55 GND3 34 (Pin 23) 1289.525 159.45 VCC1 11 (Pin 7) 369.525 2073.55 MD 35 (Pin 24) 1404.525 159.45 GND1 12 159.45 1863.475 GND3 36 1613.55 368.475 LATCH 13 (Pin 8) 159.45 1748.475 VCC3 37 (Pin 25) 1613.55 483.475 ENABLE 14 (Pin 9) 159.45 1633.475 CAPC 38 (Pin 26 ) 1613.55 598.475 DISABLE 15 (Pin 10) 159.45 1518.475 PB_GND 39 1613.55 713 .475 GND 16 159.45 1403.4 GND3 40 (Pin 27) 1613.55 828.475 BIASMON 17 ( Pin 11) 159.45 1288.475 PB_GND 41 1613.55 943.475 MODMON 18 (Pin 12) 159.45 1058.475 GND3 42 1613.55 1058.475 FAIL GND4 20 159.45 943.475 APCSET 44 (Pin 29) 1613.55 1288.475 PB_GND 21 159.45 828.475 GND2 45 1613.55 1403.475 APCFILT 22 (Pin 14) 159.45 713.475 MODSET 46 (Pin 30) 1613.55 1518.475 GND4 23 (Pin 15) 159.45 598.475 BIASMAX 47 (Pin 31) 1613.55 1633.475 VCC4 24 (Pin 16) 159.45 483.475 VCC2 48 (Pin 32) 1613.55 1748.475

Pad

No.

19 (Pin 13) 159.45 1058.475 RESERVED 43 (Pin 28) 1613.55 1173.475

Coordinates (µm)

X Y X Y

Signal

Name

Preliminary Data Sheet

VSC7939

Pad No.

Coordinates (µm)

Page 6 G52350-0, Rev 3.2

Tel: (800) VITESSE • FAX: (805) 987-5896 • Email: prodinfo@vitesse.com

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02/26/01