High-Speed Laser Driver Augments LiDAR Accuracy
According to Texas Instruments, its LMH13000 integrated laser driver is the first to deliver an ultra-fast 800-ps rise time and 50-mA to 5-A adjustable output current with only 2% variation across temperature. As a result, LiDAR modules in vehicles and autonomous mobile robots are able to measure objects more accurately.
The LMH13000 doesn't require an external FET (Fig. 1) nor a large capacitor, and it can drive lasers with rise and fall times of <800 ps with less than 2% variation across temperature. These shorter laser pulses and current control enable up to 30% longer distance measurements than today’s LiDAR systems.
The LMH13000 can accurately provide 50 mA to 5 A to a laser while maintaining eye safety (Class 1 FDA) standards (Fig. 2).
In addition, TI’s proprietary HotRod package eliminates the internal bond-wires that help achieve very low inductance in the high-current path, enabling the design to achieve faster current rise and fall times. With integrated low-voltage differential signaling (LVDS), complementary metal-oxide semiconductor (CMOS) and transistor-transistor-logic (TTL) control signals, and 3.3-V support, designers can reduce solution size by 4X compared to discrete solutions.
Features
- Voltage-controlled current driver (current sink)
- Supports continuous and pulsed operation: Continuous current is 50 mA to 1 A; pulsed current is 50 mA to 5 A
- Rise time (tr): 1-ns rise time
- Pulsed train: Up to 250 MHz
- Low- and high-current modes
- 18-V tolerance on IOUT
- Supports LVDS, TTL, CMOS logic
- Wide power supply voltage: 3 to 5.5 V
- Integrated thermal shutdown and power-down
Applications
- Automobiles with autonomous features
- Autonomous mobile robots
- Time-of-flight (ToF) range finders
- 3D scanning and mapping
- Gesture recognition
- Medical in-vitro diagnostics
- Flow cytometry
- Industrial optical sensors used in systems such as drones.
The LMH13000 can be ordered from distributors for about $4 in 1k quantities. An eval board, LMH13000RQEEVM, is also available, at the time of this writing, for about $200.
For Electronic Design readers' convenience, the LMH13000 datasheet is provided below, though it would be wise to obtain the latest revision and other LMH13000 design resources from TI before starting a design.
