The LTC®4284 negative voltage hot swap controller drivesexternal N-channel MOSFETs to allow a board to be safelyinserted and removed from a live backplane. The dual-gate,multi-mode drivers optimize the MOSFET safe operatingarea (SOA) for a variety of power levels. The SOAtimer limits MOSFET temperature rise for reliable protectionagainst overstresses.
An I2C interface and onboard gear-shift ADC allow monitoringof board current, voltage, power, energy, and faultstatus. An available single-wire broadcast mode simplifiesthe interface by eliminating two isolators. The includedEEPROM provides black-box capturing and nonvolatileconfiguration of fault behavior.
Additional features respond to input UV/OV, interrupt thehost when a fault has occurred, notify when output poweris good, detect insertion of a board, turn off the MOSFETsif an external supply monitor fails to indicate power goodwithin a timeout period, and auto-reboot after a programmabledelay following a host commanded turn-off.
Feature
- Drives Two Gates for High Power Applications
- Configurable Parallel, Staged Start or Single Modes
- Protects MOSFET with SOA Timer
- Programmable 15mV to 30mV Current Limit Sense Voltage with 2% Accuracy and Adjustable Foldback
- 8-Bit to 16-Bit Gear-Shift ADC with 0.5% Accuracy
- Monitors Voltages, Currents, Power and Energy
- Nonvolatile Configuration and Fault Recording
- Floating Topology for Rugged High Voltage Operation
- Selectable Inrush Control: dV/dt or Current Limit
- I2C/SMBus or Single-Wire Broadcast Interfaces
- Min/Max ADC Measurement Logging with Alerts
- Reboots on I2C Command with Programmable Delay
- Adjustable Input UV/OV Thresholds and Hysteresis
- 44-Pin 5mm × 8mm QFN Package
Applications
- Telecom Infrastructure
- −48V Distributed Power Systems
- Servers and Data Centers
- Power Monitors
