General Description

The MAX5927/MAX5929 +1V to +13.2V quad hot-swap

controllers provide complete protection for multisupply

systems. They allow the safe insertion and removal of cir-

cuit cards into live backplanes. These devices hot swap

multiple supplies ranging from +1V to +13.2V, provided

one supply is at or above +2.7V and only one supply is

above +11.0V. The input voltage rails (channels) can be

configured to sequentially turn-on/off, track each other,

or have completely independent operation.

The discharged filter capacitors of the circuit card pro-

vide low impedance to the live backplane. High inrush

currents 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 MAX5927/MAX5929 hot-swap controllers prevent

such problems by gradually ramping up the output volt-

age and regulating the current to a preset limit when the

board is plugged in, allowing the system to stabilize

safely. After the startup cycle is complete, on-chip com-

parators 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 condition. The

MAX5929A automatically restarts after a fault condition,

while the MAX5929L must be unlatched. The MAX5927

fault management mode is selectable.

The MAX5927/MAX5929 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 cur-

rent regulation and current glitch protection to eliminate

external timing resistors and capacitors. The

MAX5929_L provides an open-drain active-low status

output for each channel, the MAX5929_H provides an

open-drain active-high status output for each channel,

and the MAX5927 status output polarity is selectable.

The MAX5927 is available in a 32-pin thin QFN package

and the MAX5929 is available in a 24-pin QSOP pack-

age. All devices are specified over the extended tem-

perature range, -40°C to +85°C.

Applications

Features

♦ Safe Hot Swap for +1V to +13.2V Power Supplies

♦ Adjustable Circuit Breaker/Current-Limit

Threshold from 25mV to 100mV

♦ Configurable Tracking, Sequencing, or

Independent Operation Modes

♦ VariableSpeed/BiLevel Circuit-Breaker Response

♦ Internal Charge Pumps Generate N-Channel

MOSFET Gate Drives

♦ Inrush Current Regulated at Startup

♦ Autoretry or Latched Fault Management

♦ Programmable Undervoltage Lockout

♦ Status Outputs Indicate Fault/Safe Condition

Low-Voltage, Quad, Hot-Swap

Controllers/Power Sequencers

________________________________________________________________ Maxim Integrated Products

1

17

18

19

20

21

22

23

GATE3

SENSE3

IN3

N.C.

LIM3

GATE2

SENSE2

8

7

6

5

4

3

2

STAT1

GATE4

SENSE4

IN4

LIM4

GATE1

SENSE1

MAX5927

THIN QFN

1

IN1

24

IN2

TOP VIEW

Pin Configurations

Ordering Information

19-2945; Rev 1; 1/04

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

EVALUATION

KIT

AVAILABLE

PART

TEMP RANGE

PIN-PACKAGE

MAX5927ETJ

-40°C to +85°C

32 Thin QFN-EP

MAX5929LHEEG

-40°C to +85°C

24 QSOP

MAX5929LLEEG

-40°C to +85°C

24 QSOP

MAX5929AHEEG

-40°C to +85°C

24 QSOP

MAX5929ALEEG

-40°C to +85°C

24 QSOP

VariableSpeed/BiLevel is a trademark of Maxim Integrated

Products, Inc.

PCI Express Hot Plug

Hot Plug-In Daughter Cards

RAID

Power-Supply

Sequencing/Tracking

Basestation Line Cards

Portable Computer Device

Bays (Docking Stations)

Network Switches, Routers,

Hubs

Selector Guide and Typical Operating Circuit appear at end

of data sheet.

EP = Exposed paddle.

Pin Configurations continued at end of data sheet.