基于LTC4280设计的热插拔控制技术

Linear 公司的LTC4280是带I2C兼容监视的热插拔控制器,从而允许板能安全插入和拔出带电的背板. LTC4280的I2C接口和板上8位ADC能监视负载电流,电压和故障状态.工作电压从2.9V到15V,可调过流滤波器时间,具有用于外接N-MOSFET的高边驱动,输入过压/欠压保护,主要用于带电板的插入,电路断路器,计算机和服务器以及平台管理.本文介绍LTC4280主要特性, 方框图, 带5A断路器的12V应用电路以及在背板中的典型应用电路.

LTC4280: Hot Swap Controller with I2C CompaTIble Monitoring

The LTC4280 Hot Swap™ controller allows a board to be safely inserted and removed from a live backplane. Using an external N-channel pass transistor, board supply voltage
and inrush current are ramped up at an adjustable rate. An I2C interface and onboard ADC allow for monitoring of load current, voltage and fault status.

The device features adjustable analog foldback current limit and a FILTER pin which confi gures the TIme spent in overcurrent before declaring a fault. An I2C interface may confi gure the part to latch off or automaTIcally restart after the LTC4280 detects a current limit fault.

The controller has addiTIonal features to interrupt the host when a fault has occurred, notify when output power is good, detect insertion of a load card, and power-up either
automatically upon insertion or wait for an I2C command to turn on.

LTC4280主要特性:

Allows Safe Insertion into Live Backplane

8-Bit ADC Monitors Current and Voltage

I2C/SMBus Interface

Wide Operating Voltage Range: 2.9V to 15V

Adjustable Overcurrent Filter Time

High Side Drive for External N-Channel MOSFET

No External Gate Capacitor Required

Input Overvoltage/Undervoltage Protection

Optional Latchoff or Auto-Retry After Faults

Alerts Host After Faults

Inrush Current Limit with Foldback

Available in 24-Pin 4mmx 5mm QFN Package

LTC4280应用:

Live Board Insertion

Electronic Circuit Breakers

Computers, Servers

Platform Management

图1.LTC4280方框图

图2.带5A断路器的12V应用电路

图3.LTC4280典型应用电路图

图4.LTC4280 5V背板典型应用:插入激活接通和5A断路器