IEEE 802.3af PD Power over Ethernet Interface Controller with Dual Current Limit The LTC4257IS8-1#PBF is a Hot Swap controller manufactured by Linear Technology (now part of Analog Devices). Below are its key specifications, descriptions, and features:
### **Specifications:**
- **Manufacturer:** LINEAR (Linear Technology)
- **Package:** SOIC-8
- **Operating Voltage Range:** 9V to 80V
- **Operating Temperature Range:** -40°C to +85°C
- **Current Limit Accuracy:** ±5%
- **Fault Timer Accuracy:** ±15%
- **Quiescent Current:** 300µA (typical)
- **Gate Drive Voltage:** 10V (typical)
- **Power Good Output:** Yes
- **Adjustable Current Limit:** Yes
- **Adjustable Fault Timer:** Yes
### **Descriptions:**
The LTC4257IS8-1#PBF is a negative voltage Hot Swap controller designed to safely insert and remove boards from live -48V backplanes. It provides inrush current control, short-circuit protection, and power-good monitoring. The device features an adjustable current limit and fault timer for precise control over power-up conditions.
### **Features:**
- **Wide Operating Voltage Range (9V to 80V):** Suitable for -48V systems.
- **Adjustable Current Limit:** Allows precise control of inrush current.
- **Programmable Fault Timer:** Prevents prolonged overcurrent conditions.
- **Power Good (PWRGD) Output:** Indicates when the output is within regulation.
- **Under-Voltage Lockout (UVLO):** Ensures proper startup conditions.
- **Overcurrent Protection:** Safeguards against short circuits.
- **Low Quiescent Current:** Minimizes power consumption.
- **SOIC-8 Package:** Compact and industry-standard footprint.
This device is commonly used in telecom, networking, and industrial applications where reliable hot-swapping of negative voltage supplies is required.
