155Mbps to 622Mbps SFF/SFP Laser Driver with Extinction Ratio Control
Low-Cost 155Mbps Laser Driver with Extinction Ratio Control
DescriptionThe MAX3646 is a +3.3V laser driver designed for multirate 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 compensation, and built-in thermal compensation. The APC loop maintains constant average optical power. Modulation compensation increases the modulation current in proportion to the bias current. These control loops, combined 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) modulation 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 photocurrent 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.
- 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
- 125Mbps Ethernet SFP, GBIC, and 1 x 9 Transceivers
- Multirate OC-3 to OC-12 FEC Transceivers
|Part Number||Target Oper. Range|
MAX3646EVKIT: Evaluation Kit for the MAX3646
Technical DocumentsApp Note 4227 HFAN-02.7.0 Reducing Laser Driver Output Noise When No Input Signal Is Applied
App Note 3725 HFAN-02.6.0: Reducing Noise and Wander in Low-Speed (<622Mbps) Optical Transmitters
|Device||Fab Process||Technology||Sample size||Rejects||FIT at 25°C||FIT at 55°C||Material Composition|
|App Note||4227||HFAN-02.7.0 Reducing Laser Driver Output Noise When No Input Signal Is Applied|
|App Note||3725||HFAN-02.6.0: Reducing Noise and Wander in Low-Speed (<622Mbps) Optical Transmitters|