Analog Devices ADN2845 Datasheet

a

10.709 Gbps High Speed Data Switch
ADN2845

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
Automatic Laser Shutdown, ALS
CML Data Inputs
50  Internal Data Terminations

3.3 V Single-Supply Operation
Driver Supplied in Die Format Only

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

FUNCTIONAL BLOCK DIAGRAM

ADN2845

DATAP

50

DATAN

50

GENERAL DESCRIPTION

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.

The ADN2845 may be used in conjunction with the ADN2844
control chip. This chipset (ADN2843) offers a unique control
algorithm to control both average power and extinction ratio of
the laser diode.

For transmission line applications, contact the HSN Applications
Group at [e-mail]

V

CC

LD

IMODP

IBIAS

ALS

IMOD_CTRL

IBIAS_CTRL

REV. 0

Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties that
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective companies.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] www.analog.com
Fax: [phone] © 2003 Analog Devices, Inc. All rights reserved.

ADN2845-SPECIFICATIONS

(V

= 3.0 V to 3.6 V. All specifications T

ELECTRICAL CHARACTERISTICS

CC

as specified at 25ⴗC.)

Parameter Min Typ Max Unit Conditions

LASER BIAS (BIAS)

Output Current I

BIAS

380mA

Compliance Voltage 1.2 V

during ALS 10 ASee Note 1

I

BIAS

ALS Shutdown Response Time 10 s

MODULATION CURRENT (LMODP, IMODN) See Note 2

Output Current I

MOD

580mA

Compliance Voltage 1.2 V

during ALS 10 A

I

MOD

Rise Time 25 ps
Fall Time 23 ps
Random Jitter 170 fs rms See Note 3
Total Jitter 7.41 ps p-p See Note 4

DATA INPUTS (DATAP, DATAN)

V p-p(Single-Ended Peak-to-Peak) 300 800 mV
Input Impedance 50 

LOGIC INPUTS (ALS)

V

IH

V

IL

2.4 V

0.8 V

IMOD_CTRL Input See Note 5

Gain (IMOD_CTRL to I

)1015.5 A/A

MOD

Input Voltage 1.5 V

IBIAS_CTRL Input See Note 5

Gain (IBIAS_CTRL to I

)912A/A

BIAS

Input Voltage 1.5 V

SUPPLY

V

CC

I

CC

NOTES

1

In ALS mode, approximately 15 mA is sourced to the laser from the IBIAS pin, which reverse biases the laser.

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 2

5

It is recommended to decouple these pins to VCC rather than GND.

6

IBIAS = 0, IMOD = 0 (when ALS is asserted). See Power Dissipation section on page 4 for calculation of complete power dissipation.

Specifications subject to change without notice.

13

– 1 PRBS pattern with 80 CIDs input pattern at 10.7 Gbps rate.

3.0 3.3 3.6 V
75 mA See Note 6

to T

MIN

–1.0 V

CC

CC

, unless otherwise noted. Typical values

MAX

V

ABSOLUTE MAXIMUM RATINGS*

(TA = 25°C, unless otherwise noted.)

VCC to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 V

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

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

ALS to GND . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to 4.2 V

IMOD_CONTROL to GND . . . . . . . . . . . . . –0.5 V to 4.2 V

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

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

+1.2 V

CC

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 indicated in the operational
section of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability.

max) . . . . . . . . . . . . . . . . . . . 150°C

J

ORDERING GUIDE

Temperature Package Qty.

Model Range Description Min.

ADN2845ACHIPS –40ºC to +85ºC Die Form 100

REV. 0–2–

ADN2845

PIN CONFIGURATION

DATAN

GND

GND

DATAP

CC

V

1

PAD PITCH: 200␮m

NC

DIE SIZE: 1140␮m ( 20␮m)
ⴛ 1340␮m (
DIE THICKNESS: 0.25mm
SINGLE PAD SIZE: 92␮m ⴛ 92␮m
DOUBLE PAD SIZE: 151␮m ⴛ 92␮m

ALS

VCCV

ADN2845

20␮m)

IMOD_CTRL

CC

GND

GND

IBIAS_CTRL

V

CC

(IMODN TERM)

NC

IMODP

IBIAS

NC

PIN FUNCTION DESCRIPTIONS

Pin
No. Mnemonic Function

1 DATAN AC-Coupled CML Data, Negative

Differential Terminal

2GND Negative Supply

3NCNo Connect. Leave floating.

4GND Negative Supply

5 DATAP AC-Coupled CML Data, Positive

Differential Terminal

6 ALS Automatic Laser Shutdown Logic Input

7IMOD_CTRL Modulation Current Control Input

(Control circuit sinks IMOD/10 from
pin to GND.)

8IBIAS_CTRL BIAS Current Control Input (Control

circuit sinks IBIAS/10 from pin to GND.)

9GND Negative Supply

10 NC No Connect. Leave floating.

11 IBIAS BIAS Current

12 IMODP Modulation Current

13 NC No Connect. Leave floating.

14 V

CC

VCC Connection for IMODN
Termination Resistor

15 GND Negative Supply

16 V

17 V

18 V

CC

CC

CC

Positive Supply

Positive Supply

Positive Supply

METALLIZATION PHOTOGRAPH

GNDV

V

CC

V

CC

(IMODN TERM)

NC

IMODP

IBIAS

NC

GNDIBIAS_CTRLALS IMOD_CTRL

1

DATAN

1340␮m

(ⴞ20␮m)

DATAP

GND

NC

GND

V

CC

CC

1140␮m

(ⴞ20␮m)

DIE PAD COORDINATES

Pad No. Pad Name X (␮m) Y (␮m)

1 DATAN –500.00 400.00
2 GND
3NC –500.00 0.00
4 GND

2

2

–500.00 222.00

–500.00 –222.00
5 DATAP –500.00 –400.00
6 ALS –300.00 –600.00
7IMOD_CTRL –100.00 –600.00
8IBIAS_CTRL 100.00 –600.00
9 GND
10 NC
11 IBIAS 500.00 –200.00
12 IMODP
13 NC
14 V
15 GND
16 V
17 V
18 V

NOTES

1

The reference point with x = 0, y = 0 is the center of the die.

2

Denotes double bond pad.

2

2

2

2

(IMODN TERM)2500.00 378.00

CC

2

2

CC

2

CC

2

CC

300.00 –600.00

500.00 –400.00

500.00 –30.00

500.00 178.00

300.00 600.00

100.00 600.00

–100.00 600.00

–300.00 600.00

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
ADN2845 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.

REV. 0

–3–