The MAX5957/MAX5958 triple hot-plug controllers are
designed for PCI Express (PCIe)® applications. These
devices provide hot-plug control for 12V, 3.3V, and 3.3V
auxiliary supplies of three PCIe slots. The MAX5957/MAX5958s' logic inputs/outputs allow interfacing directly
with the system hot-plug management controller or
through an SMBus™ with an external I/O expander such
as the MAX7313. An integrated debounced attention
switch and present-detect signals simplify system design.
The MAX5957/MAX5958 drive six external n-channel
MOSFETs to control the 12V and 3.3V main outputs. The
3.3V auxiliary outputs are controlled through 0.2Ω n-channel
MOSFETs. Internal charge pumps provide the gate
drive for the 12V outputs while the gate drive of the 3.3V
output is driven by the 12V input supply clamped to 5.5V
above the respective 3.3V main supply rail. The 3.3V auxiliary
outputs are completely independent from the main
outputs with their own charge pumps.
At power-up, the MAX5957/MAX5958 keep all the
MOSFETs (internal and external) off until the supplies rise
above their respective undervoltage lockout (UVLO)
thresholds. Upon a turn-on command, the MAX5957/MAX5958 enhance the external and internal MOSFETs slowly with a constant gate current to limit the power-supply
inrush current.
The MAX5957/MAX5958 actively limit the current to protect
all outputs at all times and shut down if an overcurrent
condition occurs. After an overcurrent fault condition,
the MAX5957L/MAX5958L latch off while the MAX5957A/MAX5958A automatically restart after a restart time delay.
The MAX5957/MAX5958 are offered in latch-off or autorestart
versions (see the Selector Guide located in the full data sheet).
The MAX5957/MAX5958 are available in a 56-pin TQFN
package and operate over the -40°C to +85°C temperature
range.
Key Features
Applications/Uses
PCIe Compliant
Hot Swap 12V, 3.3V, and 3.3V Auxiliary for 3 PCIe Slots
Integrated Power MOSFETs for Auxiliary Supply Rails
Controls di/dt and dV/dt
Active Current Limiting Protects Against Overcurrent/Short-Circuit Conditions
Programmable Current-Limit Timeout
Active-Low PWRGD Signal Outputs with Programmable Power-On Reset (POR) (160ms Default)
Latched Active-Low FAULT Signal Output After Overcurrent or Overtemperature Fault
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