Status
Not Recommended for New Designs
Description
The MAX5918 and MAX5919 are +1V to +13.2V dual
hot-swap controllers with independent on/off control for
complete protection of dual-supply systems. They allow
the safe insertion and removal of circuit cards into live
backplanes. The MAX5918 and MAX5919 operate
down to 1V provided one of the inputs is above 2.7V.
The discharged filter capacitors of the circuit card provide
low impedance to the live backplane. High inrush
currents from the backplane to the circuit card can burn
up connectors and components, or momentarily collapse
the backplane power supply leading to a system reset.
The MAX5918 and MAX5919 hot-swap controllers prevent
such problems by gradually ramping up the output
voltage and regulating the current to a preset limit when
the board is plugged in, allowing the system to stabilize
safely. After the startup cycle is completed, two on-chip
comparators provide VariableSpeed/BiLevel™ protection
against short-circuit and overcurrent faults, as well as
immunity against system noise and load transients. In the
event of a fault condition, the load is disconnected. The
MAX5918L and MAX5919L must be unlatched after a
fault and the MAX5918A and MAX5919A automatically
restart after a fault.
The MAX5918 and MAX5919 integrate an on-board
charge pump to drive the gates of low-cost, external N-channel
MOSFETs. The devices offer integrated features
like startup current regulation and current glitch
protection to eliminate external timing resistors and
capacitors. These devices provide open-drain status
outputs, an adjustable startup timer and adjustable current
limits. The MAX5918 provides output undervoltage/
overvoltage protection for each channel, while the
MAX5919 provides undervoltage/overvoltage monitoring
for each channel.
The MAX5918 and MAX5919 are available in a space-saving
16-pin QSOP package and are specified over
the extended -40°C to +85°C temperature range.
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