Linear Technology LTC1647-3IGN Hot Swap Controller

The LTC1647-3IGN is a sophisticated hot swap controller designed by Linear Technology, now part of Analog Devices, to ensure safe board insertion and removal from live backplanes. This controller is specifically engineered to manage the inrush current that occurs when a board connects to a live power supply, thereby preventing damage to connectors, components, and the power supply itself.

Featuring a wide operating voltage range, the LTC1647-3IGN is versatile and can be used in various applications. It is particularly suited for systems with supply voltages from 2.7V to 16.5V, making it an ideal choice for both low voltage and intermediate bus voltage hot swap applications. The product comes in a robust 16-pin narrow SSOP package, which is designed for space-constrained environments.

One of the key features of the LTC1647-3IGN is its adjustable current limit, which allows users to set the maximum inrush current to a level that their specific application can handle. This is achieved through an external sense resistor. Moreover, the controller offers a programmable timer that sets the duration of the overcurrent condition before the fault is declared, ensuring flexibility and protection tailored to the user's needs.

The LTC1647-3IGN also includes a foldback current limit feature which reduces the current limit as the load voltage drops. This helps to protect the board in the event of a short circuit. Additionally, the device provides a soft start capability that limits the voltage slew rate at the output, further safeguarding against excessive inrush current.

For diagnostic and control purposes, the LTC1647-3IGN offers a range of useful signals. It provides a PWRGD (Power Good) output to indicate when the output voltage is within nominal operating range, and a FAULT output that signals when an overcurrent or overtemperature condition occurs. To ensure reliable operation, the device also features an overtemperature protection that shuts down the external MOSFET during excessive heat conditions.

In summary, the LTC1647-3IGN from Linear Technology is a comprehensive solution for hot swap applications, offering precise control and robust protection mechanisms. Its adjustable settings and diagnostic outputs make it a flexible and reliable choice for managing power distribution in high-availability systems.