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19-1518; Rev 0; 9/99
USB Current-Limited Switches
with Fault Blanking
General Description
The MAX1693/MAX1694 are current-limited, 60mΩ
switches with built-in fault blanking. Their accurate pre-
set current limit of 0.7A to 1.0A makes them ideally suit-
ed for USB applications. Their low quiescent supply
current (14µA) and shutdown current (1µA) conserve
battery power in portable applications. The MAX1693/
MAX1694 operate with inputs from +2.7V to +5.5V,
making them ideal for both +3V and +5V systems.
A fault signal notifies the microprocessor that the inter-
nal current limit has been reached. A 10ms fault-blank-
ing 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 MAX1693, an output overcurrent condition caus-
es the switch to current limit at 0.7A to 1.0A and
FAULT
to go low after the 10ms blanking period. When the
overcurrent condition is removed,
FAULT
returns to its
high-impedance state. In the MAX1694, any overcur-
rent longer than 10ms will latch the switch open and set
FAULT
low. The latch is cleared by cycling the
ON
input or by powering up the device again. This feature
saves power by preventing the device from thermally
cycling on and off in case of a persistent short-circuit
condition.
The MAX1693/MAX1694 have several safety features to
ensure that the USB port is protected. Built-in thermal-
overload protection limits power dissipation and junc-
tion temperatures. Both devices have accurate internal
current-limiting circuitry to protect the input supply
against overload. They are available in space-saving
10-pin µMAX packages.
Features
o
Accurate Current Limit (0.7A min, 1.0A max)
o
Guaranteed 0.75A Short-Circuit Protection
o
10ms Internal Fault-Blanking Timeout
o
No Fault Signal During Power-Up
o
Latched
FAULT
Output Turns Off Power Switch
(MAX1694)
o
Thermal Shutdown Protection
o
+2.7V to +5.5V Supply Range
o
14µA Supply Current
o
Small 10-Pin µMAX Package
o
UL Recognition Pending
MAX1693/MAX1694
Applications
USB Ports and Hubs
Notebook Computers
Portable Equipment
Docking Stations
Hot Plug-In Power Supplies
Battery-Charger Circuits
Ordering Information
PART
MAX1693EUB
MAX1694EUB
TEMP. RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
10 µMAX
10 µMAX
Typical Operating Circuit
Pin Configuration
INPUT
+2.7V TO +5.5V
IN
OUT
OUTPUT
TOP VIEW
IN
1
OUT
IN
OUT
ON
2
3
4
5
10
OUT
9
IN
OUT
FAULT
GND
ON
OFF
ON
GND
FAULT
MAX1693
MAX1694
MAX1693
MAX1694
8
7
6
µMAX
________________________________________________________________
Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
USB Current-Limited Switches
with Fault Blanking
MAX1693/MAX1694
ABSOLUTE MAXIMUM RATINGS
IN,
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
MAX1693EUB/MAX1694EUB ..........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10sec) .............................+300°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.
ELECTRICAL CHARACTERISTICS
(V
IN
= +5V,
T
A
= 0°C to +85°C,
unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
Operating Voltage
Quiescent Current
Off-Supply Current
Undervoltage Lockout
Off-Switch Leakage
UVLO
SYMBOL
V
IN
I
Q
V
ON
= GND, I
OUT
= 0
Timer not running
Timer running
2.0
0.01
CONDITIONS
MIN
2.7
14
35
0.001
1
2.6
2
µA
T
A
= 0°C to +85°C
V
IN
= 4.4V to 5.5V
V
IN
= 4.4V to 5.5V
V
IN
= 3V
700
72
850
500
60
15
90
125
150
1000
700
0.8
2
2.4
±1
0.4
1
7
10
1
80
3
6
165
200
20
13
mA
mA
V
V
µA
V
µA
ms
ms
µs
µs
°C
mΩ
TYP
MAX
5.5
25
UNITS
V
µA
µA
V
V
ON
= V
IN
= V
OUT
= 5.5V
Rising edge, 100mV hysteresis
V
ON
= V
IN
,
V
IN
= 5.5V,
V
OUT
= GND
T
A
= +25°C
R
ON
I
LIMIT
I
SC
V
IL
V
IH
T
A
= +25°C
On-Resistance
Current Limit
Continuous Short-Circuit
Current Limit
ON
Input Logic Low Voltage
ON
Input Logic High Voltage
ON
Input Leakage
FAULT
Output Logic Low
Voltage
FAULT
Output High Leakage
Current
Fault-Blanking Timeout Period
Start-Up Time
Switch Turn-On Time
Switch Turn-Off Time
Thermal Shutdown Threshold
T
A
= 0°C to +85°C
(Note 1)
OUT shorted to GND, MAX1693 only (Note 2)
V
IN
= 2.7V to 5.5V
V
IN
= 2.7V to 3.6V
V
IN
= 3.7V to 5.5V
V
ON
= V
IN
or GND
V
OL
I
SINK
= 1mA, V
IN
= 3V
V
IN
= V
FAULT
= 5.5V
t
FB
From overcurrent condition to
FAULT
assertion
V
IN
= 5V, C
OUT
= 150µF, R
L
= 15Ω,
from
ON
driven low to 50% full V
OUT
t
ON
t
OFF
I
LOAD
= 400mA
I
LOAD
= 400mA
2
_______________________________________________________________________________________
USB Current-Limited Switches
with Fault Blanking
ELECTRICAL CHARACTERISTICS
(V
IN
= +5V,
T
A
= -40°C to +85°C,
unless otherwise noted.) (Note 3)
PARAMETER
Operating Voltage
Quiescent Current
Off-Supply Current
Undervoltage Lockout
Off-Switch Leakage
On-Resistance
Current Limit
Continuous Short-Circuit
Current Limit
ON
Input Logic Low Voltage
ON
Input Logic High Voltage
ON
Input Leakage
FAULT
Output Logic Low
Voltage
FAULT
Output High Leakage
Current
Fault-Blanking Timeout Period
Switch Turn-On Time
Switch Turn-Off Time
t
FB
t
ON
t
OFF
V
OL
V
IL
V
IH
R
ON
I
LIMIT
UVLO
SYMBOL
V
IN
I
Q
V
ON
= GND, I
OUT
= 0, timer not running
V
ON
= V
IN
= V
OUT
= 5.5V
Rising edge, 100mV hysteresis
V
ON
= V
IN
= 5.5V, V
OUT
= GND
V
IN
= 4.4V to 5.5V
V
IN
= 3V
(Note 1)
OUT shorted to GND, MAX1693 only (Note 2)
V
IN
= 3V to 5.5V
V
IN
= 3V to 3.6V
V
IN
= 3.7V to 5.5V
V
ON
= V
IN
or GND
I
SINK
= 1mA, V
IN
= 3V
V
IN
= V
FAULT
= 5.5V
From overcurrent condition to
FAULT
assertion
I
LOAD
= 400mA
I
LOAD
= 400mA
1
6
2
2.4
±1
0.4
1
14
200
20
640
2.0
CONDITIONS
MIN
3
TYP
MAX
5.5
25
2
2.9
15
125
150
1060
750
0.8
UNITS
V
µA
µA
V
µA
mΩ
mA
mA
V
V
µA
V
µA
ms
µs
µs
MAX1693/MAX1694
3
Note 1:
MAX1693’s current limit is tested by forcing V
OUT
to 4.5V. The MAX1694’s current limit is tested by increasing the output cur-
rent until the switch is latched off.
Note 2:
This specification applies to the MAX1693 only. The MAX1694 latches the switch off under a sustained (>10ms) short-
circuit condition.
Note 3:
Specifications to -40°C are guaranteed by design, not production tested.
_______________________________________________________________________________________
USB Current-Limited Switches
with Fault Blanking
MAX1693/MAX1694
Typical Operating Characteristics
(V
IN
= +5V, T
A
= +25°C, unless otherwise noted.)
OFF-SUPPLY CURRENT
vs. TEMPERATURE
V
ON
= V
IN
OFF-SUPPLY CURRENT (nA)
10
MAX1693/4 toc03
QUIESCENT CURRENT vs. INPUT VOLTAGE
MAX1693/4 toc01
QUIESCENT CURRENT vs. TEMPERATURE
V
IN
= 5V
15
QUIESCENT CURRENT (µA)
14
13
12
11
10
9
0.01
-40
-20
0
20
40
60
80
100
-40
-20
TEMPERATURE (°C)
V
IN
= 3V
MAX1693/4 toc02
16
14
QUIESCENT CURRENT (µA)
12
10
8
6
4
2
0
0
1
2
3
4
5
6
INPUT VOLTAGE (V)
V
ON
= GND
I
OUT
= O
16
100
1
0.1
0
20
40
60
TEMPERATURE (°C)
80
100
OFF-SWITCH CURRENT vs. TEMPERATURE
MAX1693/4 toc04
NORMALIZED ON-RESISTANCE
vs. TEMPERATURE
MAX1693/4 toc05
NORMALIZED OUTPUT CURRENT
vs. OUTPUT VOLTAGE
I
LIMIT
MAX1693/4 toc06
1000
V
0N
= V
IN
OFF-SWITCH CURRENT (nA)
100
1.4
I
OUT
= 425mA
1.2
NORMALIZED R
ON
1.0
0.8
0.6
0.4
1.2
NORMALIZED OUTPUT CURRENT
1.0
0.8
SHORT-CIRCUIT CURRENT
0.6
0.4
0.2
0
10
1
0.1
0.2
0.01
-40
-20
0
20
40
60
80
100
TEMPERATURE (°C)
0
-40
-20
0
20
40
60
80
100
TEMPERATURE (°C)
0
1
2
3
4
5
6
OUTPUT VOLTAGE (V)
TURN-ON TIME vs. TEMPERATURE
MAX1693/4 toc07
TURN-OFF TIME vs. TEMPERATURE
I
LOAD
= 425mA
V
IN
= 5V
MAX1693/4 toc08
FAULT-BLANKING TIMEOUT
vs. TEMPERATURE
MAX1693/4 toc09
160
I
LOAD
= 425mA
140
120
100
t
ON
(µs)
80
60
40
20
0
-40
-20
0
20
40
60
80
V
IN
= 5V
V
IN
= 3V
7
6
5
t
OFF
(µs)
4
3
2
1
0
12
FAULT-BLANKING TIMEOUT (ms)
10
8
6
4
2
0
I
OUT
= 850mA
V
IN
= 3V OR 5V
-40
-20
0
20
40
60
80
V
IN
= 3V
100
-40
-20
0
20
40
60
80
100
100
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
4
_______________________________________________________________________________________
USB Current-Limited Switches
with Fault Blanking
Typical Operating Characteristics (continued)
(V
IN
= +5V, T
A
= +25°C, unless otherwise noted.)
MAX1693
CURRENT-LIMIT AND FAULT RESPONSE
MAX1693/4 toc10
MAX1693/MAX1694
MAX1693
CURRENT-LIMIT RESPONSE
1
MAX1693/4 toc11
1
2
2
3
3
4
2ms/div
CH1 = V
IN
, 200mV/div, AC-COUPLED; CH2 = V
OUT
,
5V/div; CH3 = V
FAULT
, 5V/div; CH4 = I
OUT
, 500mA/div
4
10µs/div
CH1 = V
IN
, 200mV/div, AC-COUPLED; CH2 = V
OUT
,
5V/div; CH3 = V
FAULT
, 5V/div; CH4 = I
OUT
, 1A/div
MAX1693
SWITCH TURN-ON TIME
MAX1693/4 toc13
MAX1693
SWITCH TURN-OFF TIME
MAX1693/4 toc14
1
2
1
2
3
3
4
20µs/div
CH1 = V
OUT
, 5V/div; CH2 = V
ON
, 5V/div;
CH3 = V
FAULT
, 5V/div; CH4 = I
OUT
, 200mA/div
4
1µs/div
CH1 = V
OUT
, 5V/div; CH2 = V
ON
, 5V/div;
CH3 = V
FAULT
, 5V/div; CH4 = I
OUT
, 200mA/div
MAX1694
OVERCURRENT TO FAULT
AND SWITCH LATCHED OFF
MAX1693/4 toc15
MAX1693
START-UP TIME
(TYPICAL USB APPLICATION)
1
MAX1693/4 toc16
1
C
L
= 150µF
R
L
= 15Ω
FULL-CURRENT LIMIT CHARGES CAPACITOR
RESISTOR
LOAD
CURRENT
2
2
3
3
4
2ms/div
CH1 = V
FAULT
, 5V/div; CH2 = I
OUT
, 5V/div;
CH3 = I
OUT
, 1A/div
FOLDBACK-
CURRENT LIMIT
1ms/div
CH1 = V
OUT
, 5V/div; CH2 = V
ON
, 5V/div;
CH3 = I
OUT
, 500mA/div; CH4 = V
FAULT
, 5V/div
_______________________________________________________________________________________
5

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