Analog Devices ADN2843 Datasheet

10.709 Gbps Laser Diode

a

FEATURES
Data Rates from 9.952 Gbps to 10.709 Gbps
Typical Rise/Fall Time 25 ps/23 ps
Bias Current Range 3 mA to 80 mA
Modulation Current Range 5 mA to 80 mA
Monitor Photodiode Current 50 A to 1200 A
Closed-Loop Control of Both Average Optical Power

and Extinction Ratio
Laser Fail and Laser Degrade Alarms
Automatic Laser Shutdown, ALS
Dual MPD Functionality for Wavelength Control
CML Data Inputs
50  Internal Data Terminations

3.3 V Single-Supply Operation
Driver Supplied in Dice Format

APPLICATIONS
SONET OC-192, SDH STM-64
Supports 10.667 Gbps and 10.709 Gbps FEC Rates
10 Gb Ethernet IEEE802.3ae

Driver Chipset

ADN2843

GENERAL DESCRIPTION

The ADN2943 chipset consists of two components, the ADN2845
and the ADN2844. The ADN2845 is a 10.709 Gbps laser diode
driver. The ADN2845 eliminates the need to ac couple since it
can deliver 80 mA of modulation while dc coupled to the laser
diode. It is intended to be copackaged with the laser to minimize
bond lengths, which improves performance of the optical
transmitter. For transmission line applications, contact HSN
Application Group at [e-mail].

The ADN2844 offers a unique control loop algorithm and pro­vides dual loop control of both average power and extinction ratio.

Programmable alarms are provided for laser fail (end of life) and
laser degrade (impending fail).

Both the ADN2844 and the ADN2845 are available as bare die.
The ADN2844 is also available in 5 mm ¥ 5 mm 32-lead LFCSP.

FUNCTIONAL BLOCK DIAGRAM

CC

IMPD

*

*

V

CC

GND

IMPDMON2

IMMON

IMPDMON

CONTROL

ERCAP PAVCAP

IDTONE

IBMON

V

MPD

IMPD2

GND

MODE

ALS

PSET

GND

ERSET

GND

*ADN2850 OR ADN2860 OPTICAL SUPERVISOR

FAIL

ADN2844

DEGRADE

ADN2843

D_IMOD

GND

IMOD_CTRL

IBIAS_CTRL

ASET

IMODN

V

V

CC

ALS

V

CC

ADN2845

GND

GND

CC

LD

IMODP

DATAP

DATAN

IBIAS

REV. 0

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ADN2843–SPECIFICATIONS

(VCC = 3.0 V to 3.6 V, All specifications T
values as specified at 25C.)

MIN

to T

, unless otherwise noted. Typical

MAX

Parameter Min Typ Max Unit Conditions

LASER BIAS (BIAS)

Output Current I
Compliance Voltage 1.2 V
I

during ALS 10 A See Note 1

BIAS

ALS Shutdown Response Time 10 s

BIAS

380mA

– 1.0 V

CC

MODULATION CURRENT (IMODP, IMODN) See Note 2

Output Current I
Compliance Voltage 1.2 V
I

during ALS 10 A

MOD

Rise Time 25 ps

MOD

580mA

CC

V

Fall Time 23 ps
Random Jitter 170 fs rms See Note 3
Total Jitter 7.41 ps p-p See Note 4

POWER SET INPUT (PSET)

External Capacitance 80 pF See Note 5
Voltage 1.15 1.35 V

EXTINCTION RATIO SET INPUT (ERSET)

Allowable Resistance Range 1.5 25 k
Voltage 1.15 1.35 V

ALARM SET (ASET)

Allowable Resistance Range 1.2 13.2 k
Voltage 1.15 1.35 V
Hysteresis 5 %

CONTROL LOOP

Time Constant 0.22 s

DATA INPUTS (DATAP, DATAN)

V p-p (Single-Ended Peak-to-Peak) 300 800 mV

Input Impedance

(Single-Ended)

50



LOGIC INPUTS (ALS, MODE)

V

IH

V

IL

2.4 V

0.8 V

ALARM OUTPUTS (Internal 30 k to VCC)

V

OH

V

OL

2.4 V

0.4 V

IDTONE

f

IN

Input Current Range 50 4000 A

10 1000 kHz

Voltage on IDTONE VCC – 2 V

MONITOR PD (MPD, MPD2)

Current 50 1200 A
Input Voltage 1.65 V

IBMON, IMMON, IMPDMON, IMPDMON2

IBMON, IMMON Division Ratio 100 A/A
IMPDMON, IMPDMON2 1 A/A
IMPDMON to IMPDMON2 Matching 2 %

Measured at 1200 A

Compliance Voltage 0 VCC – 1.5 V

SUPPLY

V

CC

I

(ADN2844) 36 mA See Note 6

CC

I

(ADN2845) 75 mA See Note 6

CC

NOTES

1

In ALS mode current is sourced to the laser from the I

2

The ADN2845 high speed specifications are measured into a 5  load.

3

RMS jitter measured with a 0000 0000 1111 1111 repeating pattern at 10.7 Gbps rate.

4

Peak-to-peak total jitter measured with a 213 – 1 PRBS with 80 CIDs pattern at 10.7 Gbps rate.

5

Max capacitance refers to capacitance of photodiode and other parasitic capacitance.

6

I

= 0, I

BIAS

Specifications subject to change without notice.

= 0 (when ALS is asserted). See Power Dissipation section on page 7 for calculation of complete power dissipation.

MOD

pin, which reverse biases the laser.

BIAS

3.0 3.3 3.6 V

REV. 0–2–

ADN2843

ABSOLUTE MAXIMUM RATINGS*

(TA = 25°C, unless otherwise noted.)

VCC to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2 V

Digital Inputs (ALS, MODE) . . . . . . . . –0.5 V to V

IMODN, IMODP . . . . . . . . . . . . . . . . . . . . . . . . . V

+ 0.3 V

CC

+ 1.2 V

CC

MOD_CONTROL to GND . . . . . . . . . . . . . . –0.5 V to 4.2 V

IBIAS_CONTROL to GND . . . . . . . . . . . . . . –0.5 V to 4.2 V

D_MOD to GND . . . . . . . . . . . . . . . . . . . . . . –0.5 V to 4.2 V

DATAP to GND . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to 4.2 V

DATAN to GND . . . . . . . . . . . . . . . . . . . . . . –0.5 V to 4.2 V

Operating Temperature Range

Industrial . . . . . . . . . . . . . . . . . . . . . . . . . . .–40°C to +85°C

Storage Temperature Range . . . . . . . . . . . . . –65°C to +150°C

Junction Temperature (T

*Stresses above those listed under Absolute Maximum Ratings may cause perma-

nent damage to the device. This is a stress rating only; functional operation of the
device at these or any other conditions above those listed in the operational
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.

Max) . . . . . . . . . . . . . . . . . . 150°C

J

ADN2844 METALLIZATION PHOTOGRAPH

IBMON

IMMON

ALS

IDTONE

GND

ORDERING GUIDE

Temperature Package

Model Range Option

ADN2843CHIPSET –40°C to +85°C ADN2844 Control

Loop: 32-Lead LFCSP
ADN2845 Data
Switch: Dice

ADN2843CHIPSET-B –40°C to +85°C ADN2844 Control

Loop: Dice
ADN2845 Data
Switch: Dice

EVAL-ADN2843 Evaluation Board

GND

DEGRADE

GND

FAIL

V

IBIAS_CTRL

GND

IMOD_CTRL

D_IMOD

GND

GND

CC

ASET

ERSET

PSET

GND

3000␮m

IMPD

IMPDMON

IMPD2

IMPDMON2

GND

GND

GND

MODE

PAV CAP

ERCAP

V

CC

GND

CAUTION

ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection. Although the
ADN2843 features proprietary ESD protection circuitry, permanent damage may occur on devices
subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended
to avoid performance degradation or loss of functionality.

2390␮m

REV. 0

–3–

ADN2843

ADN2845 METALLIZATION PHOTOGRAPH

DATAN

1340m

(20m)

DATAP

GND

NC

GND

V

CC

V

CC

GNDV

CC

GNDIBIAS_CTRLALS IMOD_CTRL

1140m

(20m)

PIN CONFIGURATIONS

V

CC

(IMODN TERM)

NC

IMODP

IBIAS

NC

ASET

ERSET

PSET

GND

IMPD

IMPDMON

IMPDMON2

IMPD2

D_IMOD

GND

GND

32 31 30 29

1

2

3

4

5

6

7

8

ADN2844

BOND PAD SIZE: >115m
BOND PAD PITCH: >104m
DIE SIZE: 3000m  2390m

9101112

CC

V

GND

ERCAP

GND

IMOD_CTRL

28 27 26

13 14 15

GND

MODE

PAVCAP

VCCIBIAS_CTRL

GND

25

16

GND

GND

24

IDTONE

23

IBMON

22

IMMON

21

ALS

20

FAIL

19

DEGRADE

18

GND

17

GND

DATAN

GND

NC

GND

DATAP

CC

V

VCCV

1

ADN2845

PAD PITCH: 200m
MAXIMUM DIE SIZE: 1.16mm 

1.36mm
DIE THICKNESS: 0.25mm
SINGLE PAD SIZE: 92m  92m
DOUBLE PAD SIZE: 151m  92m

ALS

IMOD_CTRL

CC

GND

GND

IBIAS_CTRL

V

CC

(IMODN TERM)

NC

IMODP

IBIAS

NC

REV. 0–4–