The LTC4282 ensures safe insertion and removal of 2.9V to 33V backplanes (common rails in distributed power systems) by controlling external N-channel MOSFETs to gradually turn on capacitors, preventing sparking, connector damage, and system failures. High-current, hot-plug boards use parallel MOSFETs to reduce voltage drop, but all such MOSFETs require a safe operating area (SOA) to withstand potential overcurrent damage. Further cost savings can be achieved with a gradual-start configuration that employs a low-SOA MOSFET on one trace and a low-RDS(ON) MOSFET on the other. The LTC4282 provides a compact and rugged solution for monitoring and hot-plugging, especially on high-power circuit boards used in servers, network routers, switches, and enterprise data systems.
Located at the power supply gate, the ±0.7% accurate analog-to-digital converter (ADC) reports board voltage, current, power consumption, and energy consumption via an I2C/SMBus digital interface. Under overcurrent conditions, the LTC4282 progressively reduces its precise 2% current limit to maintain constant MOSFET power dissipation for an adjustable period. The current limit can be configured digitally, allowing dynamic adaptation to load changes and facilitating the selection of low-value resistors. Maximum and minimum electrical parameter values are recorded, with alerts triggering when thresholds are exceeded (8 bits). An internal EEPROM provides non-volatile storage for register configuration and fault log data. To prevent critical board damage, the MOSFETs are constantly monitored for undesirable conditions such as low input voltage, drain-to-source short circuits, or large voltage drops.
Suitable for commercial temperatures between 0°C and 70°C and industrial temperatures between -40°C and 85°C, the LTC4282 is offered in 32-pin 5mm x 5mm QFN packages. Its starting price is $6.31 per unit for orders of 1,000 units.
Caption: Dual MOSFET Hot Swap Controller for kilowatts and range from 2.9V to 33V with ADC, I2C/SMBus interface and EEPROM
Summary of features: LTC4282
• Enables safe insertion into active backplanes
• 12/16-bit ADC with unadjusted total error of ±0.7%
• I2C/SMBus interface for reading board voltage, current, power, and energy usage
• Internal EEPROM for configuration storage and fault logging
• Wide operating voltage range: 2.9V to 33V
• Features for high-current applications
: o Dual MOSFET gate control and current sensing
o 12V gate control to minimize MOSFET RDS(ON)
o Power limiting for MOSFETs with current reduction
• Digital features:
o Digitally adjustable current limit and undervoltage, overvoltage, and power good thresholds
o Stores minimum and maximum measurements
o Alerts when programmed thresholds are reached
o Three GPIO (General Purpose Input/Output) pins
• Continuous MOSFET health monitoring
• Undervoltage and overvoltage protection
• 5mm x 5mm QFN package 32-pin
