MAX5912

 Provides Safe Hot Swap for -16V to -65V Power Supplies
 280mA Current Limit for MAX5911
 415mA Current Limit for MAX5912
 Zero-Current Load Disconnect
 Integrated Power FET
 Status Output Reports Fault Condition
 Internal Switch-Protection Circuitry
 Built-In Thermal Shutdown
 DGND Can Vary Up to ±5V with Respect to AGND

IP Phones Network Routers Network Switches Internet Appliances Power-Over-LAN

VIN ......................................................................................+0.3V to -70V
VOUT ........................................................................+0.3V to (VIN - 0.3V)
ENABLE to DGND .................................................................-0.3V to +11V
ENABLE to VIN ....................................................................-0.3V to +70V
FAULT to DGND....................................................................-0.3V to +11V
UVLO to VIN.........................................................................-0.3V to +11V
DGND........................................................................................-5V to +5V
DGND to VIN........................................................................-0.3V to +70V
FAULT Sink Current .........................................................................10mA
Voltages are with respect to AGND, unless otherwise noted.
Continuous Output Current ..........................................Internally Limited
Continuous Power Dissipation (TA = +70°C)
8-Pin SO (derate 5.9mW/°C above +70°C)..................................470mW
16-Pin SO (derate 12.9mW/°C above +70°C)............................1039mW
Operating Temperature Range .......................................-40°C to +85°C
Junction Temperature....................................................................+150°C
Storage Temperature Range ........................................-60°C to +150°C
Lead Temperature (soldering, 10s) ..............................................+300°C

The MAX5911/MAX5912 are fully integrated hot-swap switches for negative supply rails. These devices allow the safe insertion and removal of circuit cards into live backplanes or ports without causing problematic glitches on the negative power-supply rail. They also monitor various circuit parameters and disconnect the load if a fault condition occurs, alerting the host with a logic-level FAULT output. The MAX5911/MAX5912 operate over a voltage range of -16V to -65V and are designed to permit hot plugging of an IP phone into a hub, but are not limited to that operation.

During startup, an internal power FET regulates the current between the backplane power source and the load to 280mA for MAX5911 and 415mA for MAX5912. After startup, the FET is fully enhanced to reduce its on-resistance. To ensure robust operation, the MAX5911/ MAX5912 contain built-in safety features that prevent damage to the internal FET. They include an enable input, which responds to positive logic signals (+3.3V or +5V), allowing the host system to disconnect the load. ENABLE is also used to reset the device after a latching fault condition occurs.

The MAX5911/MAX5912 Simple Swapper™ hot-swap ICs monitor four parameters for these fault conditions: undervoltage lockout (UVLO), power-not-good, zerocurrent detection, and thermal shutdown. These devices are available in the extended temperature range, -40°C to +85°C. The MAX5911 and MAX5912 come in 8-pin and 16-pin SOIC packages, respectively.