MAXIM MAX3840 Technical data

General Description

The MAX3840 is a dual 2 ✕2 asynchronous crosspoint
switch for SDH/SONET DWDM and other high-speed
data switching applications where serial data stream
loop-through and protection channel switching are
required. It is ideal for OC-48 systems with forward
error correction. A high-bandwidth, fully differential sig­nal path minimizes jitter accumulation, crosstalk, and
signal skew. Each 2 ✕2 crosspoint switch can fan out
and/or multiplex up to 2.7Gbps data and 2.7GHz clock
signals. All inputs and outputs are current mode logic
(CML) compatible and easily adaptable to interface
with an AC-coupled LVPECL signal. When not used,
each CML output stage can be powered down with an
enable control to conserve power. The typical power
consumption is 460mW with all outputs enabled.

The MAX3840 is compatible with the MAX3876

2.5Gbps clock and data recovery (CDR) circuit.

The MAX3840 is available in a 32-pin exposed-pad
QFN package (5mm ✕5mm footprint) and operates
from a +3.3V supply over a temperature range of -40°C
to +85°C.

________________________Applications

SDH/SONET and DWDM Transport Systems

Add-Drop Multiplexers

ATM Switch Cores

WDM Cross-Connects

High-Speed Backplanes

Features

♦ Single +3.3V Supply
♦ 460mW Power Consumption
♦ 2ps

RMS

Random Jitter

♦ 7ps

P-P

Deterministic Jitter

♦ Power-Down Feature for Deselected Outputs
♦ CML Inputs/Outputs
♦ 6ps Channel-to-Channel Skew
♦ 100ps Output Edge Speed
♦ 5mm

✕

5mm 32 QFN or Thin QFN Package

MAX3840

+3.3V, 2.7Gbps Dual 2 ✕2 Crosspoint Switch

________________________________________________________________ Maxim Integrated Products 1

MAX3866

TIA AND LA

MAX3876

CDR

MAX3840

CROSSPOINT

SWITCH

ZO = 50Ω TRANSMISSION LINE

DATA

CLOCK

MAX3866

TIA AND LA

MAX3876

CDR

DATA

CLOCK

MAX3869

MAX3869

LASER

DRIVER

LASER

DRIVER

VCC = +3.3V

Typical Application Circuit

19-1854; Rev 5; 9/07

Ordering Information

PART

TEMP RANGE

PIN -

PK G
C O D E

MAX3840ETJ+

32 TQFN T3255-3

MAX3840EGJ

32 QFN G3255-1

Pin Configurations appear at end of data sheet.

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.

+Denotes a lead-free package.

PA C K A G E

-40°C to +85°C

-40°C to +85°C

MAX3840

+3.3V, 2.7Gbps Dual 2 ✕2 Crosspoint Switch

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS

(VCC= +3.0V to +3.6V, TA= -40°C to +85°C. Typical values are at VCC= +3.3V, TA= +25°C, unless otherwise noted.)

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

Supply Voltage, VCC.............................................-0.5V to +5.0V

Input Voltage (CML) .........................(VCC - 1.0) to (V

CC

+ 0.5V)

TTL Control Input Voltage...........................-0.5V to (V

CC

+ 0.5V)

Output Currents (CML) .......................................................22mA

Continuous Power Dissipation (T

A

= +85°C)
32-Pin TQFN

(derate 21.3mW/°C above +85°C).................................1.38W

32-Pin QFN

(derate 21.3mW/°C above +85°C).................................1.38W

Operating Temperature Range ...........................-40°C to +85°C

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

Storage Temperature Range .............................-65°C to +160°C

Lead Temperature (soldering, 10s) .................................+300°C

PARAMETER

CONDITIONS

UNITS

Supply Current I

CC

All outputs enabled

mA

CML INPUT AND OUTPUT SPECIFICATIONS

CML Differential Output Swing RL = 50Ω to V

CC

(Figure 2)

mV

P-P

Differential Output Impedance

Ω

CML Output Common-Mode
Voltage

R

L

= 50Ω to V

CC

V

CC

- 0.2 V

CML Single-Ended Input
Voltage Range

V

IS

V

CML Differential Input Voltage
Swing

mV

P-P

CML Single-Ended Input
Impedance

42.5 50 57.5 Ω

TTL SPECIFICATIONS

TTL Input High Voltage V

IH

V

TTL Input Low Voltage V

IL

0.8 V

TTL Input High Current I

IH

µA

TTL Input Low Current I

IL

-10 +10 µA

SYMBOL

MIN TYP MAX

140 190

640 800 1000

85 100 115

VCC - 0.8 VCC + 0.5

300 2000

2.0

-10 +10

MAX3840

+3.3V, 2.7Gbps Dual 2 ✕2 Crosspoint Switch

_______________________________________________________________________________________ 3

AC ELECTRICAL CHARACTERISTICS

(VCC= +3.0V to +3.6V, TA= -40°C to +85°C. Typical values are at VCC= +3.3V, TA= +25°C, unless otherwise noted.) (Note 1)

PARAMETER

CONDITIONS

CML Input and Output Data
Rate

2.7

CML Input and Output Clock
Rate

2.7

CML Output Rise and Fall Time tr, t

f

20% to 80% 100 136 ps

CML Output Random Jitter RJ (Note 2) 2

CML Output Deterministic Jitter DJ (Note 3)

CML Output Differential Skew t

skew1

Any differential pair

ps

CML Output Channel-to­Channel Skew

t

skew2

Any two outputs

ps

Propagation Delay from Input­to-Output

t

d

ps

CML Differential Output Swing
for 2.7Gbps Input Data

RL = 50Ω to V

CC

(Note 4)

CML Differential Output Swing
for 2.7GHz Input Clock

RL = 50Ω to V

CC

(Note 5)

Note 1: AC characteristics are guaranteed by design and characterization.
Note 2: Measured with 100mV

P-P

noise (f ≤ 2MHz) on the power supply.

Note 3: Deterministic jitter (DJ) is the arithmetic sum of pattern-dependent jitter and pulse-width distortion.
Note 4: Measured with 300mV

P-P

differential 1010... data pattern driving the inputs.

Note 5: Measured with 300mV

P-P

differential clock at 2.7GHz driving the inputs.

SYMBOL

MIN TYP MAX

720ps

725

15 40

185

600 mV

520 mV

UNITS

Gbps

GHz

ps

RMS

-

P-P

P-P