MAX1930
Current-Limited Switch for Two USB Ports
________________________________________________________________ Maxim Integrated Products 1
OUT
1
2
87OUT
OUTIN
IN
GND
SO
TOP VIEW
3
4
6
5
MAX1930
OUTNC
EN
Typical Operating Circuit
19-2385; Rev 2; 11/02
Pin Configuration
Ordering Information
General Description
The MAX1930 current-limited 70mΩ switch with built-in
fault blanking provides an accurate, preset 1.2A to 2.3A
current limit, making it ideal for dual USB applications.
Its low quiescent supply current (16µA) and standby
current (1µA) conserve battery power in portable applications. The MAX1930 operates with inputs from 2.7V to
5.5V, making it ideal for both 3V and 5V systems.
The MAX1930 has several safety features to ensure that
the USB port is protected. Built-in thermal-overload
protection limits power dissipation and junction temperature. The device also has accurate internal current-limiting
circuitry to protect the input supply against overload.
The MAX1930 is offered in a space-saving 8-pin SO
package and operates over the extended (-40°C to
+85°C) temperature range.
Applications
Notebook Computers
USB Ports and Hubs
Docking Stations
Features
♦ Pin Compatible with TPS2010–TPS2013
♦ Accurate Current Limit (1.2A min, 2.3A max)
♦ 125mΩ (max) High-Side MOSFET
♦ Short-Circuit and Thermal Protection
♦ Undervoltage Lockout
♦ 16µA Quiescent Supply Current
♦ 1µA (max) Standby Supply Current
♦ 2.7V to 5.5V Supply Range
♦ UL Recognized: UL# E211395
PART TEMP RANGE PIN-PACKAGE
MAX1930ESA -40°C to +85°C 8 SO
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.
INPUT
2.7V TO 5.5V
OFF
ON
IN OUTPUTOUT
MAX1930
EN
GND
MAX1930
Current-Limited Switch for Two USB Ports
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, EN to GND ..........................................................-0.3V to +6V
OUT to GND ................................................-0.3V to (V
IN
+ 0.3V)
Maximum Switch Current.........................2.3A (internally limited)
OUT Short Circuit to GND ..........................................Continuous
Continuous Power Dissipation (T
A
= +70°C)
8-Pin SO (derate 5.88mW/°C above +70°C)................471mW
Operating Temperature Range (extended).........-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
OPERATING CONDITION
Input Voltage V
IN
2.7 5.5 V
POWER SWITCH
TA = +25°CV
IN
= 4.4V to 5.5V 70
VIN = 4.4V to 5.5V
Switch Static Drain-Source
On-Resistance
)
TA = 0°C to +85°C
V
IN
= 3V 72
mΩ
Switch Turn-On Time t
ON
I
LOAD
= 400mA 80
µs
Switch Turn-Off Time t
OFF
I
LOAD
= 400mA 3 6 20 µs
ENABLE INPUT (EN)
VIN = 2.7V to 3.6V 2.0
EN High-Level Input Voltage V
IH
VIN = 3.7V to 5.5V 2.4
V
EN Low-Level Input Voltage V
IL
VIN = 2.7V to 5.5V 0.8 V
EN Input Current V EN = VIN or GND -1 +1 µA
Startup Time
V
IN
= 5V, C
OUT
= 150µF from EN driven low
to 50% full V
OUT
1ms
CURRENT LIMIT
Overload Output Current I
LIMIT
Force V
OUT
to 4.5V 1.2
2.3 A
Short-Circuit Output Current I
SC
OUT shorted to GND 1 1.5 A
SUPPLY CURRENT
Supply Current, Low-Level Input
V EN = VIN = V
OUT
= 5.5V
1µA
Timer not running 16 25
Supply Current, High-Level Input
I
Q
V EN = 0, I
OUT
= 0
Timer running 35
µA
TA = +25°C
2
Supply Leakage Current
V
EN
= VIN = 5.5V,
V
OUT
= 0
T
A
= 0°C to +85°C15
µA
UNDERVOLTAGE LOCKOUT
Undervoltage Lockout UVLO Rising edge, 100mV hysteresis 2.0 2.4 2.6 V
THERMAL SHUTDOWN
Thermal-Shutdown Threshold
°C
100
R
DS(ON
125
150
200
1.75
0.002
0.01
165
MAX1930
Current-Limited Switch for Two USB Ports
_______________________________________________________________________________________ 3
Note 1: Specifications to -40°C are guaranteed by design, not production tested.
ELECTRICAL CHARACTERISTICS
(VIN= 5V, TA= -40°C to +85°C, unless otherwise noted.) (Note 1)
PARAMETER
CONDITIONS
OPERATING CONDITION
Input Voltage V
IN
3.0 5.5 V
POWER SWITCH
VIN = 4.4V to 5.5V
Switch Static Drain-Source
On-Resistance
)
VIN = 3V
mΩ
Switch Turn-On Time t
ON
I
LOAD
= 400mA
µs
Switch Turn-Off Time t
OFF
I
LOAD
= 400mA 1 20 µs
ENABLE INPUT (EN)
VIN = 3V to 3.6V 2.0
EN High-Level Input Voltage V
IH
VIN = 3.7V to 5.5V 2.4
V
EN Low-Level Input Voltage V
IL
VIN = 3V to 5.5V 0.8 V
EN Input Current V EN = VIN or GND -1 +1 µA
CURRENT LIMIT
Overload Output Current I
LIMIT
Force V
OUT
to 4.5V 1.2 2.3 A
Short-Circuit Output Current I
SC
OUT shorted to GND 1.5 A
SUPPLY CURRENT
Supply Current, Low-Level Input
V EN = VIN = V
OUT
= 5.5V 2 µA
Supply Current, High-Level Input
I
Q
V
EN
= GND, I
OUT
= 0, timer not running 25 µA
Supply Leakage Current V EN = VIN = 5.5V, V
OUT
= GND 15 µA
UNDERVOLTAGE LOCKOUT
Undervoltage Lockout UVLO Rising edge, 100mV hysteresis 2.0 2.9 V
Typical Operating Characteristics
(Circuit of Figure 2, VIN= 5V, TA = +25°C, unless otherwise noted.)
0
6
4
2
8
10
12
14
16
18
20
0 0.5 2.0 2.51.0 1.5 3.0 3.5 4.0 4.5 5.0 5.5
QUIESCENT CURRENT vs. INPUT VOLTAGE
MAX1930 toc01
INPUT VOLTAGE (V)
QUIESCENT CURRENT (µA)
I
OUT
= 0
VEN = 0
14.5
14.0
15.5
15.0
16.5
16.0
17.5
17.0
18.0
-40 -15 10 35 60 85
QUIESCENT CURRENT vs. TEMPERATURE
MAX1930 toc02
TEMPERATURE (°C)
QUIESCENT CURRENT (µA)
VIN = 5V
VIN = 3V
I
OUT
= 0
100
0.01
OFF SUPPLY CURRENT
vs. TEMPERATURE
0.1
1
10
MAX1930 toc03
TEMPERATURE (°C)
OFF SUPPLY CURRENT (nA)
-40 -15 10 35 60 85
EN = IN
OUT = OPEN
SYMBOL
R
DS(ON
MIN TYP MAX UNITS
125
150
200
0
0
0
20µs/div
MAX1930 toc10
SWITCH TURN-ON TIME
V
OUT
, 5V/div
I
OUT
,
500mA/div
V
EN
, 5V/div
0
0
0
1µs/div
MAX1930 toc11
SWITCH TURN-OFF TIME
V
OUT
, 5V/div
I
OUT
,
500mA/div
V
EN
, 5V/div
STARTUP TIME
(TYPICAL USB APPLICATION)
MAX1930 toc12
1ms/div
0
0
0
FULL CURRENT LIMIT CHARGES CAPACITOR
RESISTOR LOAD CURRENT
SHORT-CIRCUIT
CURRENT LIMIT
V
OUT
5V/div
V
EN
5V/div
IIN 1A/div
MAX1930
Current-Limited Switch for Two USB Ports
4 _______________________________________________________________________________________
0
40
20
80
60
140
120
100
160
-40 -15 10 35 60 85
TURN-ON TIME vs. TEMPERATURE
MAX1930 toc07
TEMPERATURE (°C)
TURN-ON TIME (µs)
I
OUT
= 850mA
C
OUT
= 0.1µF
VIN = 3V
VIN = 5V
4.0
5.5
6.0
5.0
4.5
7.5
7.0
6.5
8.5
8.0
9.0
-40 10-15 35 60 85
TURN-OFF TIME vs. TEMPERATURE
MAX1930 toc08
TEMPERATURE (°C)
TURN-OFF TIME (µs)
I
OUT
= 850mA
C
OUT
= 0.1µF
VIN = 3V
VIN = 5V
5V
0
0
4µs/div
MAX1930 toc09
CURRENT-LIMIT RESPONSE
VIN AC-COUPLED
500mV/div
V
OUT
, 5V/div
I
OUT
, 2A/div
100
1000
0.01
OFF SWITCH CURRENT
vs. TEMPERATURE
0.1
1
10
MAX1930 toc04
TEMPERATURE (°C)
OFF SWITCH CURRENT (nA)
-40 -15 10 35 60 85
EN = IN
V
OUT
= 0
-40 -15 35 85
NORMALIZED ON-RESISTANCE
vs. TEMPERATURE
MAX1930 toc05
TEMPERATURE (°C)
NORMALIZED R
ON
10 60
0.4
0.7
0.6
0.5
0.9
0.8
1.3
1.2
1.1
1.0
1.4
I
OUT
= 850mA
0
0.4
0.2
0.8
0.6
1.0
1.2
0 0.5 2.0 2.5 3.0 3.51.0 1.5 4.0 4.5 5.0
NORMALIZED OUTPUT CURRENT
vs. OUTPUT VOLTAGE
MAX1930 toc06
OUTPUT VOLTAGE (V)
NORMALIZED OUTPUT CURRENT
SHORT-CIRCUIT CURRENT
I
LIMIT
(1.75A)
Typical Operating Characteristics (continued)
(Circuit of Figure 2, VIN= 5V, TA = +25°C, unless otherwise noted.)
MAX1930
Current-Limited Switch for Two USB Ports
_______________________________________________________________________________________ 5
Detailed Description
The MAX1930 P-channel MOSFET power switch limits
output current to 1.2A (min) and 2.3A (max). When the
output current increases beyond the current limit
(I
LIMIT
), the current also increases through the replica
switch (I
OUT
/ 13,000). The current-limit error amplifier
compares the voltage to the internal 1.24V reference
and regulates the current back to the I
LIMIT
(Figure 1).
These switches are not bidirectional. As a result, the
input voltage must be higher than the output voltage.
Continuous Short-Circuit Protection
The MAX1930 is a short-circuit protected switch. In the
event of an output short-circuit condition, the current
through the switch is foldback-current-limited to 1A
continuous.
Thermal Shutdown
The MAX1930 has a thermal shutdown feature. The
switch turns off when the junction temperature exceeds
+165°C. When the MAX1930 cools 20°C, the switch
turns back on. If the fault short-circuit condition is not
removed, the switch cycles on and off, resulting in a
pulsed output.
Applications Information
Input Capacitor
To limit the input voltage drop during momentary output
short-circuit conditions, connect a capacitor from IN to
GND. A 1µF ceramic capacitor is adequate for most
applications; however, higher capacitor values further
reduce the voltage drop at the input (Figure 2).
Output Capacitor
Connect a 0.1µF capacitor from OUT to GND. This
capacitor helps to prevent inductive parasitics from
pulling OUT negative during turn-off.
Layout and Thermal Dissipation
It is important to optimize the switch response time to
output short-circuit conditions by keeping all traces as
short as possible to reduce the effect of undesirable
parasitic inductance. Place input and output capacitors
as close as possible to the device (no more than 5mm
away). All IN and OUT pins must be connected with
short traces to the power bus. Wide power-bus planes
provide superior heat dissipation through the
MAX1930’s IN and OUT pins.
Under normal operating conditions, the package can
dissipate and channel heat away. Calculate the maximum power dissipation as follows:
P = (I
LIMIT
)
2
✕
R
ON
where I
LIMIT
is the preset current limit (2.3A max) and
RONis the on-resistance of the switch (125mΩ max).
When the output is short circuited, foldback-current-limiting activates and the voltage drop across the switch
equals the input supply voltage. The power dissipated
across the switch increases, as does the die tempera-
Pin Description
MAX1930
P
P
P
OUT
GND
1.24V
ON
CURRENT-LIMIT
AMPLIFIER
REPLICA
AMPLIFIER
ON
EN
IN
Figure 1. Functional Diagram
PIN
NAME
FUNCTION
1 GND Ground
2, 3 IN Input. P-channel MOSFET source—connect all IN pins together and bypass with a 1µF capacitor to ground.
4 EN Active-Low Switch Enable Input. A logic low turns on the switch.
5
No Connection. This pin is not internally connected and can be connected to OUT.
6, 7, 8
OUT
Switch Output. P-channel MOSFET drain—connect all OUT pins together and bypass with a 0.1µF capacitor
to ground.
OUTNC
MAX1930
Current-Limited Switch for Two USB Ports
6 _______________________________________________________________________________________
ture. If the fault condition is not removed, the thermaloverload protection circuitry activates (see the Thermal
Shutdown section). Wide power-bus planes connected
to IN and OUT and a ground plane in contact with the
device help dissipate additional heat.
Driving Inductive Loads
A wide variety of devices (mice, keyboards, cameras,
and printers) can load the USB port. These devices commonly connect to the port with cables, which can add an
inductive component to the load. This inductance causes the output voltage at the USB port to ring during a
load step. The MAX1930 is capable of driving inductive
loads, but avoid exceeding the device’s absolute maximum ratings. Usually the load inductance is relatively
small, and the MAX1930’s input includes a substantial
bulk capacitance from an upstream regulator, as well as
local bypass capacitors, limiting overshoot. If severe
ringing occurs due to large load inductance, clamp the
MAX1930 output below 6V and above -0.3V.
Figure 2. Typical Application Circuit
MAX1930
IN
OUTPUT
OUT
INPUT
1µF
0.1µF
*
*
USB SPECIFICATIONS REQUIRE
A HIGHER VALUE CAPACITOR.
OVERCURRENT
OUTPUT
ON
OFF
GND
EN
Chip Information
TRANSISTOR COUNT: 715
PROCESS: BiCMOS
SOICN .EPS
PACKAGE OUTLINE, .150" SOIC
1
1
21-0041
B
REV.DOCUMENT CONTROL NO.APPROVAL
PROPRIETARY INFORMATION
TITLE:
TOP VIEW
FRONT VIEW
MAX
0.010
0.069
0.019
0.157
0.010
INCHES
0.150
0.007
E
C
DIM
0.014
0.004
B
A1
MIN
0.053A
0.19
3.80 4.00
0.25
MILLIMETERS
0.10
0.35
1.35
MIN
0.49
0.25
MAX
1.75
0.050
0.016L
0.40 1.27
0.3940.386D
D
MINDIM
D
INCHES
MAX
9.80 10.00
MILLIMETERS
MIN
MAX
16
AC
0.337 0.344 AB8.758.55 14
0.189 0.197 AA5.004.80 8
N MS012
N
SIDE VIEW
H 0.2440.228 5.80 6.20
e 0.050 BSC 1.27 BSC
C
HE
e
B
A1
A
D
0-8
L
1
VARIATIONS:
MAX1930
Current-Limited Switch for Two USB Ports
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 7
© 2002 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
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