MAX3646ETG+ Maxim Integrated Products, MAX3646ETG+ Datasheet

IC LSR DRVR 622MBPS 3.63V 24TQFN

MAX3646ETG+

Manufacturer Part Number
MAX3646ETG+
Description
IC LSR DRVR 622MBPS 3.63V 24TQFN
Manufacturer
Maxim Integrated Products
Type
Laser Diode Driver (Fiber Optic)r
Datasheet

Specifications of MAX3646ETG+

Data Rate
622Mbps
Number Of Channels
1
Voltage - Supply
2.97 V ~ 3.63 V
Current - Supply
47mA
Current - Modulation
85mA
Current - Bias
100mA
Operating Temperature
-40°C ~ 85°C
Package / Case
24-TQFN Exposed Pad
Mounting Type
Surface Mount
Operating Supply Voltage
3.3 V
Supply Current
47 mA
Maximum Operating Temperature
+ 85 C
Maximum Power Dissipation
1805 mW
Minimum Operating Temperature
- 40 C
Mounting Style
SMD/SMT
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
The MAX3646 is a +3.3V laser driver designed for mul-
tirate transceiver modules with data rates from
155Mbps to 622Mbps. Lasers can be DC-coupled to
the MAX3646 for reduced component count and ease
of multirate operation.
Laser extinction ratio control (ERC) combines the features
of automatic power control (APC), modulation compensa-
tion, and built-in thermal compensation. The APC loop
maintains constant average optical power. Modulation
compensation increases the modulation current in pro-
portion to the bias current. These control loops, com-
bined with thermal compensation, maintain a constant
optical extinction ratio over temperature and lifetime.
The MAX3646 accepts differential data input signals.
The wide 5mA to 60mA (up to 85mA AC-coupled) mod-
ulation current range and up to 100mA bias current
range, make the MAX3646 ideal for driving FP/DFB
lasers in fiber optic modules. External resistors set the
required laser current levels. The MAX3646 provides
transmit disable control (TX_DISABLE), single-point
fault tolerance, bias-current monitoring, and photocur-
rent monitoring. The device also offers a latched failure
output (TX_FAULT) to indicate faults, such as when the
APC loop is no longer able to maintain the average
optical power at the required level. The MAX3646 is
compliant with the SFF-8472 transmitter diagnostic and
SFP MSA timing requirements.
The MAX3646 is offered in a 4mm x 4mm, 24-pin thin
QFN package and operates over the extended -40°C to
+85°C temperature range.
19-3161; Rev 1; 7/04
Typical Application Circuit appears 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.
Multirate OC-3 to OC-12 FEC Transceivers
125Mbps Ethernet SFP, GBIC, and 1 x 9
Transceivers
Laser Driver with Extinction Ratio Control
________________________________________________________________ Maxim Integrated Products
General Description
Applications
155Mbps to 622Mbps SFF/SFP
♦ Single +3.3V Power Supply
♦ 47mA Power-Supply Current
♦ 85mA Modulation Current
♦ 100mA Bias Current
♦ Automatic Power Control (APC)
♦ Modulation Compensation
♦ On-Chip Temperature Compensation
♦ Self-Biased Inputs for AC-Coupling
♦ Ground-Referenced Current Monitors
♦ Laser Shutdown and Alarm Outputs
♦ Enable Control and Laser Safety Feature
+ Denotes a lead-free/RoHS-compliant package.
* EP = Exposed pad.
MAX3646ETG
MAX3646ETG+
PART
TOP VIEW
MODTCOMP
TX_DISABLE
*THE EXPOSED PADDLE MUST BE SOLDERED TO SUPPLY
GROUND ON THE CIRCUIT BOARD.
V
V
IN+
IN-
CC
CC
1
2
3
4
5
6
24
7
*EP
-40°C to +85°C
-40°C to +85°C
TEMP RANGE
Ordering Information
23
8
MAX3646
22
9
Pin Configuration
21
10
20
11
19
12
18
17
16
15
14
13
PIN-PACKAGE
24 Thin QFN-EP*
24 Thin QFN-EP*
MD
V
OUT+
OUT-
V
BIAS
CC
CC
Features
1

Related parts for MAX3646ETG+

MAX3646ETG+ Summary of contents

Page 1

... On-Chip Temperature Compensation ♦ Self-Biased Inputs for AC-Coupling ♦ Ground-Referenced Current Monitors ♦ Laser Shutdown and Alarm Outputs ♦ Enable Control and Laser Safety Feature PART MAX3646ETG MAX3646ETG+ + Denotes a lead-free/RoHS-compliant package Exposed pad. TOP VIEW Applications MODTCOMP TX_DISABLE *THE EXPOSED PADDLE MUST BE SOLDERED TO SUPPLY GROUND ON THE CIRCUIT BOARD ...

Page 2

SFF/SFP Laser Driver with Extinction Ratio Control ABSOLUTE MAXIMUM RATINGS Supply Voltage V ...............................................-0.5V to +6.0V CC IN+, IN-, TX_DISABLE, TX_FAULT, SHUTDOWN, BC_MON, PC_MON, APCFILT1, APCFILT2, MD, TH_TEMP, MODTCOMP, MODBCOMP, MODSET, and APCSET Voltage.............-0. Stresses ...

Page 3

Laser Driver with Extinction Ratio Control ELECTRICAL CHARACTERISTICS (continued +2.97V to +3.63V -40°C to +85°C. Typical values are otherwise noted.) (Notes 1, 2) PARAMETER SYMBOL APC Loop Time Constant APC Setting Stability ...

Page 4

SFF/SFP Laser Driver with Extinction Ratio Control (V = +3.3V 0.01µ 20mA APC BIAS OPTICAL EYE DIAGRAM 7 (622.08Mbps PRBS, 467MHz FILTER) MAX3646 toc01 1310nm FP LASER r ...

Page 5

Laser Driver with Extinction Ratio Control (V = +3.3V 0.01µ 20mA APC BIAS RANDOM JITTER vs. MODULATION CURRENT 2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0 ...

Page 6

SFF/SFP Laser Driver with Extinction Ratio Control PIN NAME Modulation-Current Compensation from Temperature. A resistor at this pin sets the temperature 1 MODTCOMP coefficient of the modulation current when above the threshold temperature. Leave open for zero ...

Page 7

Laser Driver with Extinction Ratio Control VOLTAGE SINGLE ENDED V IN+ V IN- DIFFERENTIAL ( IN+ IN- CURRENT I OUT+ TIME Figure 1. Required Input Signal and Output Polarity SOURCE NOISE VOLTAGE SUPPLY Figure 3. Supply ...

Page 8

SFF/SFP Laser Driver with Extinction Ratio Control INPUT BUFFER IN+ IN- SHUTDOWN SAFETY LOGIC TX_FAULT POWER DETECTOR TX_DISABLE R = 45kΩ PULL PC_MON R PC_MON I BIAS 82 T > ...

Page 9

Laser Driver with Extinction Ratio Control V CC POR AND COUNTER 60ms DELAY TX_DISABLE COUNTER 60ms DELAY PC_MON PC_MON I BIAS 82 BC_MON R BC_MON Figure 5. Simplified Safety Circuit Table 1. ...

Page 10

SFF/SFP Laser Driver with Extinction Ratio Control Table 2. Circuit Responses to Various Single-Point Faults CIRCUIT RESPONSE TO OVERVOLTATGE OR PIN SHORT TO V TX_FAULT Does not affect laser power. TX_DISABLE Modulation and bias currents are disabled. ...

Page 11

Laser Driver with Extinction Ratio Control Table 3. Optical Power Relations PARAMETER SYMBOL Average power P AVG Extinction ratio r e Optical power of a one Optical power of a zero P 0 Optical amplitude P ...

Page 12

SFF/SFP Laser Driver with Extinction Ratio Control of R that corresponds to the required current MODSET at +25° MOD MODS BIAS I = 268 MODS REF ...

Page 13

Laser Driver with Extinction Ratio Control Maxim Laser Drivers with Laser Diodes for more informa- tion on AC-coupling laser drivers to laser diodes. For compliance OUT+ CC MOD D The APC ...

Page 14

... Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 14 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2004 Maxim Integrated Products +3 ...

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