Hot Swap Controller 4-CH 72V 44-Pin MQFP

The MAX5914 are quadruple hot-swap controllers. The MAX5914 independently control four external N-channel switches to hot-swap system loads from a single VCC supply line. The devices allow the safe insertion and removal of power devices from live network ports. Operating supply voltage range is between +35V and +72V. The devices are intended for applications in Power-Over-Media-Dependent Interface (MDI), but are not limited to such usage. The MAX5914 feature an internal undervoltage lockout (UVLO) function that prevents the FET from turning on, if VCC does not exceed the default value of +32V. The devices also feature a +12V relay driver with 100mA current drive capable of driving low-voltage +3.3V relays. The MAX5914 features an active-low relay driver that sinks current when the relay output is enabled. The MAX5914 features an active-high relay driver output that sources 1mA to drive an external FET relay driver when the relay output is enabled. Control circuitry ensures the relays and the FETs are off until VCC reaches the UVLO threshold. The MAX5914 use an external sense resistor to enable all the internal current-sense functions. The MAX5914 feature a programmable analog current-limit circuit. If the switch remains in current limit for more than a programmable time, the N-channel FET latches off and the supply can be restarted either by autoretry or by an external command after the preset off-time has elapsed. The MAX5914 are available in a 44-pin MQFP package and are specified for the extended -40°C to +85°C operating temperature range.

• Wide Operating Input Voltage Range +35V to +72V
• IEEE 802.3AF Compatible
• Four Independent Power Switch Controllers
• Open-Circuit Detector
• On-Board Charge Pumps to Drive External N-Channel FETs
• Current Sense with External Resistor
• Foldback Current Limiting
• +32V Input Undervoltage Lockout
• On-Chip +12V, 100mA Voltage Relay Drivers