The MAX5900/MAX5901 are SOT23/TDFN hot-swap controllers that allow a circuit card to be safely hot-plugged into a live backplane without causing a glitch on the power-supply rail. These devices operate from -9V to -100V and provide the simplest hot-swap solution by eliminating all external components except an external n-channel MOSFET. The MAX5900/MAX5901 limit the inrush current to the load and provide a circuit-breaker function for overcurrent protection. During startup, the circuit-breaker function is disabled and the MAX5900/MAX5901 limit the inrush current by gradually turning on the external MOSFET. Once the external MOSFET is fully enhanced, the circuit-breaker function is enabled and the MAX5900/MAX5901 provide overcurrent protection by monitoring the voltage drop across the external MOSFET's on-resistance. The MAX5900/MAX5901 include an undervoltage lockout (UVLO) function, ON/active-low OFF control input, and a powergood status output, active-low PGOOD (MAX5900) or PGOOD (MAX5901). A built-in thermal shutdown feature is also included to protect the external MOSFET in case of overheating. The MAX5900/MAX5901 offer latched or autoretry fault management and are available with 200mV, 300mV, or 400mV circuit-breaker thresholds. Both the MAX5900 and MAX5901 are available in small SOT23 and TDFN packages, and are specified for the extended -40°C to +85°C temperature range. For specific ordering information see the Selector Guide at the end of the data sheet. Applications * Base-Station Line Cards * Network Hubs, Switches, Routers * Servers * Telecom Line Cards * Wide -9V to -100V Operation * Requires No External Sense Resistor * Drives External N-Channel MOSFET * Limits Inrush Current * Circuit-Breaker Function * Less than 1mA Quiescent Current * ON/Active-Low OFF Input Permits Load Power-Supply Control and Sequencing * Adjustable Undervoltage Lockout * Power-Good Output with 100V Rating * Latching or Automatic Retry Fault Management * Thermal Shutdown Helps Protect the External MOSFET * Space-Saving 6-Pin SOT23 and TDFN Packages