1. Overview
The NCP81295 and NCP81296 are 50A electronic resettable pass-through fuses designed for 12V high-current applications such as servers, storage systems, and base stations. These fuses integrate low-resistance MOSFETs and high-precision current sensors for monitoring and overload protection.
2. Features
Power Features:
- Integrated power switch, hot-swap controller, and current sensor
- Peak current output up to 60A, continuous current output at 50A
- Input voltage range: 4.5V to 18V
- Internal MOSFET with resistance as low as 0.65mΩ
Control Features:
- Enable input
- Optional output pull-down when disabled
- Programmable soft start
- Programmable multi-level current limiting
Reporting Features:
- Accurate analog load current monitoring
- Programmable overcurrent alert output
- Analog temperature output
- Status fault OK output
Other Features:
- 5mm x 5mm QFN32 package
- Operating temperature range: -40°C to 125°C
- Supports parallel operation for higher current applications
- Built-in insertion delay
- NCP81295: Latches after protection
- NCP81296: Auto-retries after protection
3. Applications
The document provides various application circuit diagrams, including single fuse applications, parallel fuse applications, and applications with controllers.
4. Internal Architecture Diagram
5. Relationship Between Number of Parallel Units, Soft Start Time, and Maximum Allowable Capacitive Load
6. Protection Features
Overcurrent Protection: When the current exceeds the set value, the fuse limits the current and shuts down if necessary.
Short-Circuit Protection: Rapid response to prevent damage from short circuits.
Overtemperature Protection: The fuse shuts down when the temperature exceeds the set value to prevent overheating damage.
7. Relationship Between Off-State Leakage Current and Temperature and Power Loss vs. Load Current
8. Summary
The NCP81295 and NCP81296 are high-performance hot-swap intelligent fuses designed for high-current protection applications with input voltages ranging from 4.4V to 18V. They support parallel operation to meet customer requirements for high-current applications such as various servers and storage switching systems. They feature overcurrent, short-circuit detection, overtemperature protection, extended soft-start duration, and gate leakage protection, contributing to overall input protection. Their 5mm x 5mm LQFN32 package is relatively compact and widely used for 50A-rated applications, particularly in 12V input environments. Additionally, the NCP81295 latches after protection, while the NCP81296 auto-retries after protection, allowing users to choose the appropriate functionality based on design requirements.