MAXIM MAX1931 User Manual
General Description
The MAX1931 is a current-limited, 60mΩ switch with
built-in fault blanking. Its accurate preset current limit of
0.64A to 1.06A makes it ideally suited for USB applications. The device’s low quiescent supply current (14µA)
and shutdown current (1µA) conserve battery power in
portable applications. The MAX1931 operates with
inputs from 2.7V to 5.5V, making it ideal for both 3V and
5V systems.
A fault signal notifies the microprocessor that the internal current limit has been reached. A 10ms fault-blanking feature allows momentary faults (such as those
caused when hot-swapping into a capacitive load) to be
ignored, thus preventing false alarms to the host system.
This fault blanking also prevents a fault signal from
being issued when the device is powering up.
In the MAX1931, an output overcurrent condition causes
the switch to current limit at 0.64A to 1.06A and FAULT
to go low after the 10ms blanking period. When the
overcurrent condition is removed, FAULT returns to its
high-impedance state.
The MAX1931 has several safety features to ensure that
the USB port is protected. Built-in thermal overload
protection limits power dissipation and junction temperatures. The device has an accurate internal current-limiting circuitry to protect the input supply against overload.
The MAX1931 is available in a space-saving 10-pin
µMAX package.
Applications
USB Ports and Hubs
Notebook Computers
Portable Equipment
Docking Stations
Hot Plug-In Power Supplies
Battery-Charger Circuits
Features
♦ 0.5A Guaranteed Output Current
♦ Guaranteed 0.75A Short-Circuit Protection
♦ 10ms Internal Fault-Blanking Timeout
♦ No Fault Signal During Power-Up
♦ Thermal Shutdown Protection
♦ 2.7V to 5.5V Supply Range
♦ 14µA Supply Current
♦ Small 10-Pin µMAX Package
MAX1931
Current-Limited Switch for Single USB Port
_______________________________________________________________ Maxim Integrated Products 1
Typical Operating Circuit
19-2357; Rev 0; 4/02
Pin Configuration
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.
Ordering Information
PART TEMP RANGE PIN-PACKAGE
MAX1931EUB -40°C to +85°C 10µMAX
TOP VIEW
OUT
1
IN
2
MAX1931
3
IN
4
5
MAX
µ
10
OUT
9
IN
8
OUT
7
FAULTOUT
GNDON
6
INPUT
2.7V TO 5.5V
IN
OUT
OUTPUT
MAX1931
FAULT
OFF
ON
ON
GND
MAX1931
Current-Limited Switch for Single USB Port
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VIN= 5V, TA= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
IN, ON (ON), FAULT to GND....................................-0.3V to +6V
OUT to GND ................................................-0.3V to (V
IN
+ 0.3V)
Maximum Continuous Switch Current .....1.2A (internally limited)
OUT Short Circuit to GND ..........................................Continuous
Continuous Power Dissipation (T
A
= +70°C)
10-Pin µMAX (derate 5.6mW/°C above +70°C) ............444mW
Operating Temperature Range ............................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
VON= GND, I
OUT
= 0
I
SINK
= 1mA, VIN= 3V
VON= VINor GND
V
OUT
= 4.5V
VIN= 2.7V to 3.6V
VIN= 2.7V to 5.5V
TA= +25°C
VON= VIN= V
OUT
= 5.5V
Rising edge, 100mV hysteresis
VON= V
IN
V
IN
= 5.5V,
V
OUT
= GND
OUT shorted to GND
CONDITIONS
V0.4V
OL
FAULT Output Logic
Low Voltage
µA±1
ON Input Leakage
V
2
V
IH
ON Input Logic High Voltage
V0.8V
IL
ON Input Logic Low Voltage
mA500 700I
SC
Continuous Short-Circuit
Current Limit
µA
35
I
Q
14 35
V2.7 5.5V
IN
Operating Voltage
Quiescent Current
mA640 850 1060I
LIMIT
Current Limit
mΩ
72 180
R
ON
On-Resistance
150
60 110
µA0.001 1Off Supply Current
V2.0 2.6UVLOUndervoltage Lockout
0.01 4
µA
20
Off Switch Leakage
UNITSMIN TYP MAXSYMBOLPARAMETER
Timer not running
Timer running
TA= +25°C
TA= 0°C to +85°C
VIN= 4.4V to 5.5V
VIN= 4.4V to 5.5V
VIN= 3V
VIN= V
FAULT
= 5.5V µA1
FAULT Output High
Leakage Current
From overcurrent condition to FAULT assertion
ms61013t
FB
Fault-Blanking Timeout Period
VIN= 5V, C
OUT
= 150µF, RL= 15Ω,
from ON driven low to 50% full V
OUT
ms1Startup Time
I
LOAD
= 400mA µs3620t
OFF
Switch Turn-Off Time
I
LOAD
= 400mA µs80 200t
ON
Switch Turn-On Time
°C165Thermal Shutdown Threshold
TA= 0°C to +85°C
VIN= 3.7V to 5.5V 2.4
MAX1931
Current-Limited Switch for Single USB Port
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS
(VIN= 5V, TA= -40°C to +85°C, unless otherwise noted.) (Note 1)
VIN= V
FAULT
= 5.5V µA1
VIN= 4.4V to 5.5V
FAULT Output High
Leakage Current
VON= GND, I
OUT
= 0, timer not running
From overcurrent condition to FAULT assertion
I
SINK
= 1mA, VIN= 3V
VON= VINor GND
V
OUT
= 4.5V
VIN= 3V to 3.6V
VIN= 3V to 5.5V
ms
VON= VIN= V
OUT
= 5.5V
Rising edge, 100mV hysteresis
VIN= 3V
VON= V
IN
= 5.5V, V
OUT
= GND
OUT shorted to GND
CONDITIONS
614t
FB
Fault-Blanking Timeout Period
I
LOAD
= 400mA µs120t
OFF
Switch Turn-Off Time
I
LOAD
= 400mA µs200t
ON
Switch Turn-On Time
V0.4V
OL
FAULT Output Logic
Low Voltage
µA±1
ON Input Leakage
V
2
V
IH
ON Input Logic High Voltage
V0.8V
IL
ON Input Logic Low Voltage
mA750
Continuous Short-Circuit
Current Limit
µAI
Q
35
V3 5.5V
IN
Operating Voltage
Quiescent Current
mA600 1100I
LIMIT
Current Limit
180
150
µA2Off Supply Current
V2.0 2.9UVLOUndervoltage Lockout
µA20Off Switch Leakage
UNITSMIN TYP MAXSYMBOLPARAMETER
R
ON
On-Resistance mΩ
Note 1: Specifications to -40°C are guaranteed by design, not production tested.
VIN= 3.7V to 5.5V 2.4
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