原标题：ADI LTC4238大功率热插拔控制器解决方案

　　ADI公司的LTC4238是高压大电流热插拔控制器,能允许板能在带电底板上安全插入和拔出.双12V栅极驱动器很适合于大功率应用,安全工作在并行MOSFET或支持2级起动,以改变负载电容,接着增加低开态电阻通路到负载中.器件工作电压范围宽,从6.5V到80V,驱动两个栅极以便大功率应用.可配置并行,起动或单个MOSFET模式,可调精密电流设限,从6mV到20mV, 折返电流限制MOSFET功率,SOA计时器优化了MOSFET功能.监测VGS和VDS以保证MOSFET安全,12V栅极驱动可用于更低的MOSFET RDS(ON),并行控制器可用于非常高电流水平,24引脚窄体SSOP封装和24引脚4x5mm QFN封装.主要用在12V,24V和48V系统的带电板插入,工业高边开关/电路中断器,计算机和服务器以及电动汽车系统.本文介绍了LTC4238主要特性,框图和多种应用电路,以及演示板DC2914A主要指标,电路图和演示板DC2914A应用图.

　　The LTCR4238 is a high voltage high current Hot Swap controller that allows a board to be safely inserted and removed from a live backplane. Dual 12V gate drive is well suited for high power applications to either share safe operating area across parallel MOSFETs or support a 2-stage start-up that first charges the load capacitance followed by enabling a low on-resistance path to the load.

　　The device features active current limiting (ACL) with two foldback options as VDS increases. The constant power profile limits the power dissipation to be no higher than a fixed value, while the high power profile allows the part to ride through large input steps during operation.

　　The LTC4238 notifies when output power is good. In addition, it has protection features that respond to input undervoltage, overvoltage; and generate a fault when there is an overcurrent or FET bad condition.

　　LTC4238主要特性:

　　n Allows Safe Board Insertion into Live Backplane

　　n Wide Operating Voltage Range: 6.5V to 80V

　　n Drives Two Gates for High Power Applications

　　n Configurable Parallel, Staged Start or Single MOSFET Modes

　　n Adjustable Precision Current Limit: 6mV to 20mV

　　n Current Foldback Limits MOSFET Power

　　n SOA Timer Optimizes MOSFET Capability

　　n Monitors VGS and VDS for MOSFET Health

　　n 12V Gate Drive for Lower MOSFET RDS(ON)

　　n Parallelable Controllers for Very High Current Levels

　　n Available in 24-Lead Narrow SSOP and 24-Pin 4mm × 5mm QFN Packages

　　LTC4238应用:

　　n Live Board Insertion in 12V, 24V and 48V Systems

　　n Industrial High Side Switch/Circuit Breaker

　　n Computers, Servers

　　n Vehicle Electrical Systems

　　图1.LTC4238框图

　　图2.LTC4238应用电路:并行模式SOA计时器的48V/40A热插拔控制器

　　图3.LTC4238应用电路: 48V/60A,环境温度65度C

　　图4.LTC4238应用电路: 48V/63A

　　图5.LTC4238应用电路: 48V/16A,单个MOSFET实现HSSS模式

　　演示板DC2914A

　　DC2914A showcases the LTC®4238, high power, Hot Swap controller. LTC4238 is suited for 12V, 24V and 48V systems and comes loaded with advanced features including SOA timer, COMM pin for scalability, and various operating modes. The board has three variants to showcase the three different staged start topologies of LTC4238. The DC2914A-A showcases the parallel mode of operation for a 48V, 1.5kW application. The DC2914A-B demonstrates the low stress staged start mode for a 48V, 2.5 kW regulated input application. The DC2914A-C showcases the high stress staged start mode with SOA timer for 48V, 2.5kW application with large input steps.

　　Onboard LEDs indicate the presence of input, output as well as power good signaling and any fault if present.

　　High voltage layout rules are followed for best long-term product reliability.

　　演示板DC2914A主要指标:

　　图6. 演示板DC2914A外形图