General Description
The MAX5930A/MAX5931A/MAX5931B +1V to +15V
triple hot-swap controllers provide complete protection
for multisupply systems. They allow the safe insertion
and removal of circuit cards into live backplanes. These
devices hot swap multiple supplies ranging from +1V to
+15V, provided one supply is at or above +2.7V. The
input voltage rails (channels) can be configured to
sequentially turn-on/off, track each other, or have com-
pletely independent operation.
The discharged filter capacitors of the circuit card provide
low impedance to the live backplane. High inrush cur-
rents 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
MAX5930A/MAX5931A/MAX5931B hot-swap controllers
prevent such problems by gradually ramping up the out-
put voltage and regulating the current to a preset limit
when the board is plugged in, allowing the system to sta-
bilize safely. After the startup cycle is complete, on-chip
comparators provide VariableSpeed/BiLevel™ protection
against short-circuit and overcurrent faults, and provide
immunity against system noise and load transients.
The load is disconnected in the event of a fault condi-
tion. The MAX5930A/MAX5931A/MAX5931B fault-man-
agement mode is selectable, allowing latched fault or
autoretry after a fault condition.
The MAX5930A/MAX5931A/MAX5931B offer a variety of
options to reduce external component count and
design time. All devices integrate an on-board charge
pump to drive the gates of low-cost, external n-channel
MOSFETs, an adjustable startup timer, and an
adjustable current limit. The devices offer integrated
features like startup current regulation and current
glitch protection to eliminate external timing resistors
and capacitors. The MAX5931A provides an open-
drain, active-low status output for each channel, the
MAX5931B provides an open-drain, active-high status
output for each channel, and the MAX5930A status out-
put polarity is selectable.
The MAX5930A is available in a 24-pin QSOP package,
and the MAX5931A/MAX5931B are available in a 20-pin
QSOP package. All devices are specified over the
extended -40°C to +85°C temperature range.
Applications
Features
o Safe Hot Swap for +1V to +15V Power Supplies
with Any Input Voltage (V
IN_
) ≥ 2.7V
o Adjustable Circuit-Breaker/Current-Limit
Threshold from 25mV to 100mV
o Configurable Tracking, Sequencing, or
Independent Operation Modes
o VariableSpeed/BiLevel Circuit-Breaker Response
o Internal Charge Pumps Generate n-Channel
MOSFET Gate Drives
o Inrush Current Regulated at Startup
o Autoretry or Latched Fault Management
o Programmable Undervoltage Lockout
o Status Outputs Indicate Fault/Safe Condition
MAX5930A/MAX5931A/MAX5931B
Low-Voltage, Triple, Hot-Swap Controllers/
Power Sequencers/Voltage Trackers
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Maxim Integrated Products
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