MAXIM MAX3738 155Mbps to 2.7Gbps SFF SFP Laser Driver with Extinction Ratio Control
Summary
The MAX3738 is a high-precision laser driver designed for multi-rate fiber optic transceivers across data rates from 155Mbps to 2.7Gbps. This component is essential for engineers developing complex SFP/GBIC modules, providing superior control necessary for demanding applications like OC-3 to OC-48 FEC. The manual details the driver's advanced features, including Automatic Power Control (APC), Extinction Ratio Control (ERC), and built-in temperature compensation. These technologies ensure constant optical power and stable performance over long operating periods and wide temperature ranges. It also provides critical monitoring outputs for enhanced system reliability.
Page 1 Text Content
19-3162; Rev 1; 7/05
155Mbps to 2.7Gbps SFF/SFP Laser Driver with
Extinction Ratio Control
General Description Features
The MAX3738 is a +3.3V laser driver designed for mul- Single +3.3V Power Supply irate transceiver modules with data rates from
47m A Power-Supply Current
155Mbps to 2.7Gbps. Lasers can be DC-coupled to the MAX3738 for reduced component count and ease of
85m A Modulation Current
multirate operation.
100m A Bias Current
Laser extinction ratio control (ERC) combines the features
of automatic power control (APC), modulation compensa- Automatic Power Control (APC)
tion, and built-in thermal compensation. The APC loop
Modulation Compensation
maintains constant average optical power. Modulation compensation increases the modulation current in pro- On-Chip Temperature Compensation portion to the bias current. These control loops, com-
Self-Biased Inputs for AC-Coupling
bined with thermal compensation, maintain a constant optical extinction ratio over temperature and lifetime. Ground-Referenced Current Monitors The MAX3738 accepts differential data input signals.
Laser Shutdown and Alarm Outputs
The wide 5m A to 60m A (up to 85m A AC-coupled) mod-
Enable Control and Laser Safety Feature
ulation current range and up to 100m A bias current range, make the MAX3738 ideal for driving FP/DFB
Ordering Information
lasers in fiber optic modules. External resistors set the required laser current levels. The MAX3738 provides
TEMP PIN- PKG
transmit disable control (TX_DISABLE), single-point PART
RANGE PACKAGE CODE
fault tolerance, bias-current monitoring, and photocur-
MAX3738ETG -40°C to 85°C 24 Thin QFN T2444-3
rent monitoring. The device also offers a latched failure
output (TX_FAULT) to indicate faults, such as when the MAX3738ETG+ -40°C to 85°C 24 Thin QFN T2444-3
APC loop is no longer able to maintain the average +Denotes lead-free package.
PC _M ON TH _T EM
optical power at the required level. The MAX3738 is
BC _M ON OD BC OM
compliant with the SFF-8472 transmitter diagnostic and Typical Application Circuit appears at end of data sheet.
SFP MSA timing requirements. SH UT DO OD SE The MAX3738 is offered in a 4mm x 4mm, 24-pin thin GN AP CS ET
QFN package and operates over the extended -40°C to Pin Configuration
TX _F AU LT AP CF ILT
+85°C temperature range.
GN AP CF ILT
TOP VIEW
Applications
Multirate OC-3 to OC-48 FEC Transceivers
MODTCOMP MD
Gigabit Ethernet SFF/SFP and GBIC
VCC VCC
Transceivers
IN+ OUT+
1Gbps/2Gbps Fibre Channel SFF/SFP and GBIC
MAX3738
Transceivers IN- OUT- VCC VCC TX_DISABLE BIAS
THE EXPOSED PADDLE MUST BE SOLDERED TO SUPPLY GROUND ON THE CIRCUIT BOARD. PIN1 INDICATED BY + ON LEAD-FREE PACKAGE.
Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
Page Summary Contents For MAXIM MAX3738 155Mbps to 2.7Gbps SFF SFP Laser Driver with Extinction Ratio Control
Manual Details
| Brand | Laser |
|---|---|
| Pages | 14 |
| File Size | 370.45 KB |
| Published | May 29, 2026 |
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Frequently Asked Questions
How does the MAX3738 maintain stable optical power?
It utilizes a combination of Automatic Power Control (APC), Modulation Compensation, and built-in thermal compensation to ensure a constant optical extinction ratio.
What must happen regarding the package during installation?
The exposed paddle MUST be soldered directly to supply ground on the circuit board.
What feature indicates that the laser driver has experienced an operational fault?
A latched failure output (TX_FAULT) signals faults, such as when the APC loop cannot maintain average optical power.
What is the operating temperature range for this laser driver?
The device operates over an extended temperature range of -40°C to 85°C.