General Description

The MAX5957/MAX5958 triple hot-plug controllers are

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

o PCIe Compliant

o Hot Swap 12V, 3.3V, and 3.3V Auxiliary for 3

PCIe Slots

o Integrated Power MOSFETs for Auxiliary Supply

Rails

o Controls di/dt and dV/dt

o Active Current Limiting Protects Against

Overcurrent/Short-Circuit Conditions

o Programmable Current-Limit Timeout

o PWRGD Signal Outputs with Programmable

Power-On Reset (POR) (160ms Default)

o Latched FAULT Signal Output After Overcurrent

or Overtemperature Fault

o Attention Switch Inputs/Outputs with 4ms

Debounce

o Present-Detect Inputs

o Force-On Inputs Facilitate Testing/Debug

o Thermal Shutdown

o Allow Control Through SMBus with an I/O

Expander

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.