Linear Technology's LT4250HCN8: High Voltage Hot Swap Controller

The LT4250HCN8 is a robust high voltage Hot Swap™ controller designed by Linear Technology, now part of Analog Devices, to allow safe board insertion and removal from a live backplane. This component is engineered for controlling the power supply to electronic boards, ensuring that the system remains stable during both insertion and removal. The LT4250HCN8 is particularly well-suited for telecom and datacom applications where high availability is a critical requirement.

This Hot Swap controller operates over a wide range of input voltages, from 9V to 80V, making it versatile for various applications. It features a charge pump that eliminates the need for an external high voltage MOSFET driver, simplifying the design and reducing component count. The LT4250HCN8 provides adjustable current limit, which allows for precise control of the inrush current, thereby protecting both the board and the backplane from potentially damaging current spikes.

The device integrates several key protective features. It offers overcurrent protection with a foldback feature that reduces the current limit as the output voltage drops to manage power dissipation during a short-circuit condition. Additionally, the LT4250HCN8 includes an adjustable timer for circuit breaker functionality, which ensures that the device responds appropriately to both short-term overloads and persistent faults.

For enhanced functionality, the LT4250HCN8 provides status indicators through an ON pin, which signals when the output voltage is within nominal range, and a FAULT pin, which indicates overcurrent, overtemperature, or power bad conditions. These features enable easy monitoring and diagnostics of the power system's health.

The LT4250HCN8 comes in an 8-pin N package, offering a compact solution for space-constrained applications. Its rugged design and comprehensive feature set make it an ideal choice for managing power in high-availability systems where continuous operation and protection are paramount.

Overall, the LT4250HCN8 from Linear Technology is a reliable and efficient solution for Hot Swap applications that require precise control, robust protection, and high voltage capability.