The MAX5959/MAX5960 quad hot-plug controllers are
designed for PCI Express® (PCIe) applications. These
devices provide hot-plug control for the main 12V, 3.3V,
and 3.3V auxiliary supplies of four PCIe slots. The
MAX5959/MAX5960s' 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 MAX5959/MAX5960 drive eight 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 MAX5959/MAX5960 keep all the
MOSFETs off until the supplies rise above their respective
undervoltage lockout (UVLO) thresholds. Upon a turn-on
command, the MAX5959/MAX5960 enhance the external
and internal MOSFETs slowly with a constant gate current
to limit the power-supply inrush current.
The MAX5959/MAX5960 actively limit the current to protect
all outputs at all times and shut down if an overcurrent
condition persists longer than the programmable
overcurrent timeout. After an overcurrent or overtemperature
fault condition, the MAX5959L/MAX5960L latch off
while the MAX5959A/MAX5960A automatically restart
after a restart time delay. The MAX5959/MAX5960 are
offered in latch-off or autorestart versions (see the
Selector Guide located in the full data sheet).
The MAX5959/MAX5960 are available in an 80-pin TQFP
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 4 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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