19-1988; Rev 0; 3/01
+72V SOT23 Simple Swapper Hot-Swap
Controllers
MAX5902/MAX5903
General Description
The MAX5902/MAX5903 are SOT23 hot-swap con-
trollers that allow a circuit card to be safely hot plugged
into a live backplane without causing a glitch on the
power-supply rail. These devices operate from +9V to
+72V and provide the simplest hot-swap solution by
eliminating all external components except the external
P-channel MOSFET.
The MAX5902/MAX5903 limit the inrush current to the
load and provide a circuit breaker function for overcur-
rent protection. During startup the circuit breaker func-
tion is disabled and the MAX5902/MAX5903 limit the
inrush current by gradually turning on the external
MOSFET. Once the external MOSFET is fully enhanced,
the circuit breaker function is enabled and the
MAX5902/MAX5903 provide overcurrent protection by
monitoring the voltage drop across the external MOS-
FET’s on-resistance.
The MAX5902/MAX5903 include an undervoltage lock-
out (UVLO) function, ON/OFF control input and a
power-good status output,
PGOOD
(MAX5902) or
PGOOD (MAX5903). A built in thermal shutdown fea-
ture is also included to protect the external MOSFET in
case of overheating.
The MAX5902/MAX5903 offer latched or auto-retry fault
management and are available with 300mV, 400mV or
500mV circuit breaker thresholds. Both the MAX5902
and MAX5903 are available in a small SOT23 package,
and are specified for the extended -40°C to +85°C tem-
perature range. For specific ordering information refer
to the selector guide at the end of the data sheet.
o
Wide +9V to +72V Operation
o
Requires No External Sense Resistor
o
Drives External P-Channel MOSFET
o
Limits Inrush Current
o
Circuit Breaker Function
o
Less than 2mA Quiescent Current
o
ON/OFF Input Permits Load Power-Supply
Control and Sequencing
o
Adjustable Undervoltage Lockout
o
Power-Good Output with +72V Rating
o
Latching or Automatic Retry Fault Management
o
Thermal Shutdown Helps Protect the External
MOSFET
o
Space-Saving SOT23-6 Package
Features
Ordering Information
PART
MAX5902_
_EUT*
MAX5903_
_EUT*
TEMP. RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
6-SOT23
6-SOT23
*For specific part numbers see Selector Guide at end of data
sheet.
Applications
Network Routers
Network Switches
Base Station Line
Cards
Servers
RAID
Industrial Systems
Typical Operating Circuits
BACKPLANE CIRCUIT CARD
+48V
IRFR5410
HOT SWAP CONTROLLER
V
IN
(+)
LUCENT
JW050A1
50W ISOLATED
POWER SUPPLY
Pin Configuration
V
S
MAX5902
GATE
DRAIN
PGOOD
TOP VIEW
V
S
1
6
ON/OFF
GND
ON/OFF
GND
ON/OFF
V
IN
(-)
DRAIN
2
MAX5902
MAX5903
5
PGOOD (PGOOD)
GATE
3
4
GND
Typical Operating Circuits continued at end of data sheet.
Simple Swapper is a trademark of Maxim Integrated Products Inc.
SOT23-6
( ) ARE FOR MAX5903 ONLY.
________________________________________________________________
Maxim Integrated Products
1
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.
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
