Rainbow Electronics MAX5958 - Manual

General Description
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-chan-
nel 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 aux-
iliary 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-sup-
ply inrush current.
The MAX5957/MAX5958 actively limit the current to pro-
tect all outputs at all times and shut down if an overcur-
rent 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 auto-
restart versions (see the
Selector Guide ).
The MAX5957/MAX5958 are available in a 56-pin TQFN
package and operate over the -40°C to +85°C temper-
ature range.
Applications
Servers
Desktop Mobile Server Platforms
Workstations
Embedded Devices
Features
♦ 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
♦ PWRGD Signal Outputs with Programmable
Power-On Reset (POR) (160ms Default)
♦ Latched FAULT Signal Output After Overcurrent
or Overtemperature Fault
♦ Attention Switch Inputs/Outputs with 4ms
Debounce
♦ Present-Detect Inputs
♦ Force-On Inputs Facilitate Testing/Debug
♦ Thermal Shutdown
♦ Allow Control Through SMBus with an I/O
Expander
MAX5957/MAX5958
Triple PCI Express, Hot-Plug Controllers
________________________________________________________________ Maxim Integrated Products 1
PART TEMP RANGE
PIN-
PACKAGE PKG
CODE
MAX5957AETN+ -40°C to +85°C 56 Thin QFN T5677-1
MAX5957LETN+ -40°C to +85°C 56 Thin QFN T5677-1
MAX5958AETN+ -40°C to +85°C 56 Thin QFN T5677-1
MAX5958LETN+ -40°C to +85°C 56 Thin QFN T5677-1
PART LATCH OFF AUTORESTART GUARANTEED AUX CURRENT (mA)
MAX5957AETN+ √ 375
MAX5957LETN+ √ 375
MAX5958AETN+ √ 550
MAX5958LETN+ √ 550
Selector Guide
Ordering Information
19-0884; Rev 0; 7/07
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
+ Denotes a lead-free package.
Pin Configuration and Typical Application Circuit appear at
end of data sheet.
PCI Express is a registered trademark of PCI-SIG Corp.
SMBus is a trademark of Intel Corp.