Overview
The ONET4201LD, produced by Texas Instruments, is a high-performance laser driver designed for multiple fiber optic applications. This device operates at data rates ranging from 155 Mbps to 4.25 Gbps, making it suitable for various high-speed optical communication systems. The ONET4201LD accepts CML (Current Mode Logic) input data and provides both bias and modulation currents necessary for driving a laser diode. It features automatic power control (APC), temperature compensation of modulation current, and fault detection mechanisms. The device is packaged in a small-footprint, 4-mm × 4-mm, 24-lead QFN package and operates on a single 3.3-V supply, ensuring power efficiency and compact design.
Key Specifications
| Parameter | Description |
|---|---|
| Data Rate | 155 Mbps to 4.25 Gbps |
| Bias Current | Programmable from 1 mA to 100 mA |
| Modulation Current | Programmable from 5 mA to 85 mA |
| Supply Voltage | Single 3.3 V ±10% |
| Operating Temperature | –40°C to 85°C |
| Package | 4-mm × 4-mm, 24-lead QFN |
| Input Data | CML compatible differential signals |
| Back-Termination | Active 20-Ω back-termination at the output |
| ESD Rating | 2 kV (HBM) at all pins except MOD+, MOD– (1 kV) |
| Maximum Junction Temperature | 150°C |
Key Features
- Automatic Power Control (APC): Maintains constant optical output power by compensating for changes in laser threshold current over temperature and lifetime.
- Temperature Compensation of Modulation Current: Ensures stable modulation current across a wide temperature range.
- Fault Detection and Mode Selection: Includes hard-fault and soft-fault modes to handle different fault conditions, with the ability to disable or indicate faults accordingly.
- Bias and Photodiode Current Monitors: Provides monitoring outputs for bias and photodiode currents.
- CML Data Inputs: Accepts CML compatible differential input signals with on-chip 50-Ω termination.
- Active Back-Termination: Minimizes jitter caused by reflections with active 20-Ω back-termination at the output.
Applications
- SONET/SDH Transmission Systems: Supports high-speed data transmission in synchronous optical networking and synchronous digital hierarchy systems.
- Fibre Channel Optical Modules: Suitable for fibre channel applications requiring high-speed data transfer.
- Fiber Optic Data Links: Used in various fiber optic data link applications where high data rates are necessary.
- Digital Cross-Connects: Employed in digital cross-connect systems for efficient data routing.
- Optical Transmitters: Ideal for driving laser diodes in optical transmitter modules.
Q & A
- What is the data rate range of the ONET4201LD?
The ONET4201LD operates at data rates from 155 Mbps to 4.25 Gbps.
- What type of input data does the ONET4201LD accept?
The device accepts CML (Current Mode Logic) compatible differential input signals.
- What is the purpose of the automatic power control (APC) feature?
The APC feature maintains constant optical output power by compensating for changes in laser threshold current over temperature and lifetime.
- How is the modulation current temperature-compensated?
The modulation current is temperature-compensated to ensure stable modulation current across a wide temperature range.
- What are the fault detection modes available in the ONET4201LD?
The device includes hard-fault and soft-fault modes to handle different fault conditions.
- What is the package type and size of the ONET4201LD?
The device is packaged in a 4-mm × 4-mm, 24-lead QFN package.
- What is the operating temperature range of the ONET4201LD?
The device operates from –40°C to 85°C.
- What is the supply voltage requirement for the ONET4201LD?
The device requires a single 3.3-V supply voltage ±10%.
- What applications is the ONET4201LD suitable for?
The device is suitable for SONET/SDH transmission systems, fibre channel optical modules, fiber optic data links, digital cross-connects, and optical transmitters.
- Is the ONET4201LD still in production?
No, the ONET4201LD is being discontinued by Texas Instruments.
