MAXIM MAX1812 Technical data
For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
General Description
The MAX1812 is a dual current-limited switch specifically made for USB applications. Each channel is guaranteed to supply 500mA and meets USB specifications.
The MAX1812’s low quiescent supply current (45µA)
and shutdown current (3µA) conserve battery power in
portable applications.
The MAX1812 has multiple 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 both
overload and short-circuit conditions. Independent fault
signals (FAULTA and FAULTB) notify the microprocessor when a thermal-overload, current limit, undervoltage
lockout, or short-circuit fault occurs. A 20ms fault-blanking feature enables the circuit to ignore momentary
faults, such as those caused when hot-swapping a
capacitive load, thereby preventing false alarms to the
host system.
The MAX1812 is available in a space-saving 10-pin
µMAX package. For single versions of this device, refer
to the MAX1693, MAX1694, and MAX1607 data sheets.
________________________Applications
USB Ports
USB Hubs
Notebook Computers
Desktop Computers
PDAs and Palmtop Computers
Docking Stations
Features
♦ Dual USB Switch in Tiny 10-Pin µMAX Package
♦ Guaranteed 500mA Load per Channel
♦ Built-In 20ms Fault Blanking
♦ Compliant to USB Specifications
♦ +4.0V to +5.5V Input Voltage Range
♦ 45µA Quiescent Current
♦ 3µA Shutdown Current
♦ Independent Shutdown Control
♦ Independent FAULT Indicator Outputs
♦ Thermal-Overload Protection
♦ UL Listing Pending
MAX1812
Dual USB Switch with Fault Blanking
________________________________________________________________ Maxim Integrated Products 1
Pin Configuration
ONBONB
ONAONA
GND
MAX1812
FAULTB
FAULTA
IN
INA
INB
USB
PORT A
OUTA
USB
PORT B
OUTB
INPUT
4.0V TO 5.5V
Typical Operating Circuit
19-1865; Rev 0; 11/00
1
2
3
4
5
10
9
8
7
6
OUTA
GND
OUTBINB
IN
INA
MAX1812
µMAX
TOP VIEW
ONA
ONB FAULTB
FAULTA
Ordering Information
PART TEMP. RANGE PIN-PACKAGE
MAX1812EUB -40°C to +85°C 10 µMAX
MAX1812
Dual USB Switch with Fault Blanking
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VIN= V
INA
= V
INB
= 5V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C) (Note 1)
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, INA, INB, ONA, ONB, OUTA, OUTB to GND......-0.3V to +6V
FAULTA, FAULTB to GND .........................-0.3V to (V
IN
_ + 0.3V)
INA, IN to OUTA; INB, IN to OUTB..........................-0.3V to +6V
OUTA, OUTB Maximum Continuous Switch Current
(per channel, internally limited) .........................................1.2A
FAULTA, FAULTB Current .................................................20mA
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
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Supply Voltage Range 4.0 5.5 V
Switch On-Resistance R
Standby Supply Current Both switches disabled 3 10 µA
Quiescent Supply Current Both switches enabled, I
OUT_ Leakage Current
U nd er vol tag e Lockout Thr eshol d UVLO Rising edge, 3% hysteresis 3.0 3.4 3.8 V
Continuous Load Current 500 mA
Continuous Current Limit ILIM VIN_ - V
Short-Circuit Current Limit ISHORT V
Short-Circuit Detect Threshold (Note 2) 1 V
Continuous Current-Limit
Blanking Timeout Period
Short-Circuit Blanking Timeout
Period
Turn-On Delay
Output Rise Time
Turn-Off Delay from ON
Output Fall Time
Thermal Shutdown Threshold 15°C hysteresis 160 °C
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
ON
TA = +25°C, each switch 75 105
TA = -40°C to +85°C, each switch 135
Switches disabled, V
T
= +25°C
A
Switches disabled, V
T
= -40°C to 85°C
A
_ = 0.5V 0.6 0.9 1.2 A
OUT
OUT
_ = 0 (I
OUT
pulsing)
OUTA
OUTA
OUTA
= V
= V
= I
OUTB
OUTB
= 0 45 100 µA
OUTB
= 0,
= 0,
From continuous current-limit condition to
FAULT_ assertion
From short-circuit current-limit condition to
FAULT_ assertion
R
= 10Ω, C
OUT
rise time (from ON_ to 10% of V
R
= 10Ω, C
OUT
90% of V
R
OUT
OUT
= 10Ω, C
fall time (from ON_ to 90% of V
C
= 1µF, R
OUT
of V
OUT
= 1µF does not include
OUT
OUT
= 1µF, from 10% to
OUT
= 1µF does not include
OUT
OUT
= 10Ω, from 90% to 10%
OUT
)
)
0.002 1
10
0.8 1.2 1.6 A( peak)
0.35 A
10 20 35 ms
7.5 18 35 ms
0.5 1.2 4.0 ms
2.5 ms
0.8 3 ms
2.5 ms
mΩ
µA
RMS
MAX1812
Dual USB Switch with Fault Blanking
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(VIN= V
INA
= V
INB
= 5V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.) (Note 1)
Note 1: Specifications to -40°C are guaranteed by design, not production tested.
Note 2: The output voltage at which the device transitions from short-circuit current limit to continuous current limit.
Typical Operating Characteristics
(VIN= V
INA
= V
INB
= 5V, Circuit of Figure 2, TA = +25°C, unless otherwise noted.)
100
75
50
25
0
0312 456
QUIESCENT CURRENT
vs. INPUT VOLTAGE
MAX1812 toc01
INPUT VOLTAGE (V)
QUIESCENT CURRENT (µA)
V
ONA
= V
ONB
= 0V
40
45
50
55
-40 10-15 35 60 85
QUIESCENT CURRENT
vs. TEMPERATURE
MAX1812 toc02
TEMPERATURE (°C)
QUIESCENT CURRENT (µA)
VIN = 4.5V
VIN = 5V
VIN = 5.5V
0
1
2
3
4
5
-40 10-15 35 60 85
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
MAX1812 toc03
TEMPERATURE (°C)
SHUTDOWN SUPPLY CURRENT (µA)
V
ONA
= V
ONB
= V
IN
Logic Input High Voltage V
Logic Input Low Voltage V
Logic Input Current V
FAULT_ Output Low Voltage I
FAULT_ Output High Leakage
Current
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
= +4V to +5.5V 2 V
IN_
= +4V to +5.5V 0.8 V
IN_
SINK
V
ON_
IN_
= 0 or V
= 1mA, V
= V
FAULT_
IN_
= 4V 0.4 V
IN_
= 5.5V 1 µA
-1 1 µA
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