MAXIM MAX1693, MAX1693H, MAX1694 User Manual

General Description
The MAX1693/(MAX1693H)/MAX1694 are current-limit­ed, 60mswitches with built-in fault blanking. Their accurate preset current limit of 0.7A to 1.0A makes them ideally suited for USB applications. Their low quiescent supply current (14µA) and shutdown current (1µA) con­serve battery power in portable applications. The MAX1693/(MAX1693H)/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 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 MAX1693/(MAX1693H), an output overcurrent condition causes 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 overcurrent 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/(MAX1693H)/MAX1694 have several safety features to ensure that the USB port is protected. Built-in thermal-overload protection limits power dissi­pation and junction temperatures. All 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
Accurate Current Limit (0.7A min, 1.0A max)
Guaranteed 0.75A Short-Circuit Protection
10ms Internal Fault-Blanking Timeout
No Fault Signal During Power-UpLatched FAULT Output Turns Off Power Switch
(MAX1694)
Thermal Shutdown Protection
2.7V to 5.5V Supply Range
14µA Supply Current
Small 10-Pin µMAX Package
UL Recognized–#E211935
Applications
USB Ports and Hubs
Notebook Computers
Portable Equipment
Docking Stations
Hot Plug-In Power Supplies
Battery-Charger Circuits
MAX1693/(MAX1693H)/MAX1694
USB Current-Limited Switches
with Fault Blanking
_______________________________________________________________ Maxim Integrated Products 1
Typical Operating Circuit
19-1518; Rev 2; 9/01
PART
MAX1693EUB
MAX1693HEUB
-40°C to +85°C
-40°C to +85°C
TEMP RANGE PIN-PACKAGE
10 µMAX
10 µMAX
Pin Configuration
Ordering Information
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.
MAX1694EUB
-40°C to +85°C 10 µMAX
(ON) OFF
IN
FAULT
ON
(ON)
MAX1693
(MAX1693H)
MAX1694
GND
OUT
TOP VIEW
INPUT
2.7V TO 5.5V
1
IN
2
OUT
IN
MAX1693
3
(MAX1693H)
MAX1694
4
5
µMAX
10
OUT
9
IN
8
OUT
7
FAULTOUT
GND(ON) ON
6
ON (OFF)
OUTPUT
MAX1693/(MAX1693H)/MAX1694
USB Current-Limited Switches with Fault Blanking
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
MAX1693EUB/MAX1693HEUB/
MAX1694EUB ..................................................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
V
ON
(ON)
= GND (VIN)
I
OUT
= 0
I
SINK
= 1mA, VIN= 3V
V
ON
(ON)
= VINor GND
(Note 1)
VIN= 2.7V to 3.6V
VIN= 2.7V to 5.5V
TA= +25°C
V
ON
(ON)
= VIN= V
OUT
= 5.5V (VON= GND)
Rising edge, 100mV hysteresis
V
ON
(ON)
= VIN(GND)
V
IN
= 5.5V,
V
OUT
= GND
OUT shorted to GND, MAX1693/(MAX1693H) only (Note 2)
CONDITIONS
V0.4V
OL
FAULT Output Logic Low Voltage
µA±1
ON (ON) Input Leakage
V
2
V
IH
ON (ON) Input Logic High Voltage
V0.8V
IL
ON (ON) Input Logic Low Voltage
mA500 700I
SC
Continuous Short-Circuit Current Limit
µA
35
I
Q
14 25
V2.7 5.5V
IN
Operating Voltage
Quiescent Current
mA700 850 1000I
LIMIT
Current Limit
m
72 150
R
ON
On-Resistance
125
60 90
µA0.001 1Off-Supply Current
V2.0 2.6UVLOUndervoltage Lockout
0.01 2 µA
15
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
ms71013t
FB
Fault-Blanking Timeout Period
VIN= 5V, C
OUT
= 150µF, RL= 15,
from ON (ON) driven low (high) to 50% full V
OUT
ms1Start-Up 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
MAX1693/(MAX1693H)/MAX1694
USB Current-Limited Switches
with Fault Blanking
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS
(VIN= +5V, TA= -40°C to +85°C, unless otherwise noted.) (Note 3)
VIN= V
FAULT
= 5.5V µA1
VIN= 4.4V to 5.5V
FAULT Output High Leakage Current
V
ON
(ON)
= GND (GND), I
OUT
= 0, timer not
running
From overcurrent condition to FAULT assertion
I
SINK
= 1mA, VIN= 3V
V
ON
(ON)
= VINor GND
(Note 1)
VIN= 3V to 3.6V
VIN= 3V to 5.5V
ms
V
ON
(ON)
= VIN= V
OUT
= 5.5V (VON= GND)
Rising edge, 100mV hysteresis
VIN= 3V
V
ON
(ON)
= V
IN
= 5.5V, V
OUT
= GND
(V
ON
= GND)
OUT shorted to GND, MAX1693/(MAX1693H) only (Note 2)
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 (ON) Input Leakage
V
2
V
IH
ON (ON) Input Logic High Voltage
V0.8V
IL
ON (ON) Input Logic Low Voltage
mA750
Continuous Short-Circuit Current Limit
µAI
Q
25
V3 5.5V
IN
Operating Voltage
Quiescent Current
mA640 1060I
LIMIT
Current Limit
150
125
µA2Off-Supply Current
V2.0 2.9UVLOUndervoltage Lockout
µA15Off-Switch Leakage
UNITSMIN TYP MAXSYMBOLPARAMETER
R
ON
On-Resistance m
Note 1: MAX1693/(MAX1693H)’s current limit is tested by forcing V
OUT
to 4.5V. The MAX1694’s current limit is tested by increasing
the output current until the switch is latched off.
Note 2: This specification applies to the MAX1693/(MAX1693H) 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.
VIN= 3.7V to 5.5V 2.4
MAX1693/(MAX1693H)/MAX1694
USB Current-Limited Switches with Fault Blanking
4 _______________________________________________________________________________________
Typical Operating Characteristics
(VIN= +5V, TA= +25°C, unless otherwise noted.)
0
2
4
6
8
10
12
14
16
021 3456
QUIESCENT CURRENT vs. INPUT VOLTAGE
MAX1693/4 toc01
INPUT VOLTAGE (V)
QUIESCENT CURRENT (µA)
I
OUT
= O
V
ON (ON)
= GND (VIN)
9
11
10
13
12
15
14
16
-40 0 20-20 40 60 80 100
QUIESCENT CURRENT vs. TEMPERATURE
MAX1693/4 toc02
TEMPERATURE (°C)
QUIESCENT CURRENT (µA)
VIN = 5V
VIN = 3V
100
0.01
OFF-SUPPLY CURRENT
vs. TEMPERATURE
0.1
1
10
MAX1693/4 toc03
TEMPERATURE (°C)
OFF-SUPPLY CURRENT (nA)
-40 0-20 20406080100
VON (ON) = V
IN
(GND)
100
1000
0.01
-40 0-20 40 10080
OFF-SWITCH CURRENT vs. TEMPERATURE
0.1
1
10
MAX1693/4 toc04
TEMPERATURE (°C)
OFF-SWITCH CURRENT (nA)
20 60
V0N
(ON)
= V
IN
(GND)
-40 0-20 40 10080
NORMALIZED ON-RESISTANCE
vs. TEMPERATURE
MAX1693/4 toc05
TEMPERATURE (°C)
NORMALIZED R
ON
20 60
0
0.4
0.2
0.8
0.6
1.2
1.0
1.4 I
OUT
= 425mA
0
0.4
0.2
0.8
0.6
1.0
1.2
0231 456
NORMALIZED OUTPUT CURRENT
vs. OUTPUT VOLTAGE
MAX1693/4 toc06
OUTPUT VOLTAGE (V)
NORMALIZED OUTPUT CURRENT
SHORT-CIRCUIT CURRENT
I
LIMIT
0
40
20
80
60
140
120
100
160
-40 0-20 20406080100
TURN-ON TIME vs. TEMPERATURE
MAX1693/4 toc07
TEMPERATURE (°C)
t
ON
(µs)
I
LOAD
= 425mA
VIN = 3V
VIN = 5V
0
2
1
4
3
6
5
7
-40 0 20-20 40 60 80 100
TURN-OFF TIME vs. TEMPERATURE
MAX1693/4 toc08
TEMPERATURE (°C)
t
OFF
(µs)
I
LOAD
= 425mA
VIN = 3V
VIN = 5V
MAX1693/(MAX1693H)/MAX1694
USB Current-Limited Switches
with Fault Blanking
_______________________________________________________________________________________ 5
Typical Operating Characteristics (continued)
(VIN= +5V, TA= +25°C, unless otherwise noted.)
4
3
1
2
2ms/div
MAX1693/4 toc10
MAX1693
CURRENT-LIMIT AND FAULT RESPONSE
CH1 = VIN, 200mV/div, AC-COUPLED; CH2 = V
OUT
,
5V/div; CH3 = V
FAULT
, 5V/div; CH4 = I
OUT
, 500mA/div
4
10µs/div
3
1
2
MAX1693
CURRENT-LIMIT RESPONSE
MAX1693/4 toc11
CH1 = VIN, 200mV/div, AC-COUPLED; CH2 = V
OUT
,
5V/div; CH3 = V
FAULT
, 5V/div; CH4 = I
OUT
, 1A/div
4
3
2
1
MAX1693
SWITCH TURN-ON TIME
MAX1693/4 toc12
CH1 = V
OUT
, 5V/div; CH2 = VON, 5V/div;
CH3 = V
FAULT
, 5V/div; CH4 = I
OUT
, 200mA/div
20µs/div
0
2
6
4
10
8
12
-40 0 20-20 406080100
FAULT-BLANKING TIMEOUT
vs. TEMPERATURE
MAX1693/4 toc09
TEMPERATURE (°C)
FAULT-BLANKING TIMEOUT (ms)
I
OUT
= 850mA
VIN = 3V OR 5V
4
3
2
1
MAX1693
SWITCH TURN-OFF TIME
MAX1693/4 toc13
CH1 = V
OUT
, 5V/div; CH2 = VON, 5V/div;
CH3 = V
FAULT
, 5V/div; CH4 = I
OUT
, 200mA/div
1µs/div
4
3
2
1
MAX1693
STARTUP TIME
(TYPICAL USB APPLICATION)
MAX1693/4 toc14
CH1 = V
OUT
, 5V/div; CH2 = VON, 5V/div;
CH3 = I
OUT
, 500mA/div; CH4 = V
FAULT
, 5V/div
CL = 150µF R
L
= 15
1ms/div
FULL-CURRENT LIMIT CHARGES CAPACITOR
RESISTOR LOAD CURRENT
FOLDBACK­CURRENT LIMIT
MAX1693/(MAX1693H)/MAX1694
USB Current-Limited Switches with Fault Blanking
6 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(VIN= +5V, TA= +25°C, unless otherwise noted.)
4
3
2
1
MAX1693H
SWITCH TURN-ON TIME
MAX1693/4 toc16
CH1 = V
OUT
, 5V/div; CH2 = VON, 5V/div;
CH3 = V
FAULT
, 5V/div; CH4 = I
OUT
, 200mA/div
20ms/div
4
3
2
1
MAX1693H
SWITCH TURN-OFF TIME
MAX1693/4 toc17
CH1 = V
OUT
, 5V/div; CH2 = VON, 5V/div;
CH3 = V
FAULT
, 5V/div; CH4 = I
OUT
, 200mA/div
1ms/div
4
3
2
1
MAX1693H
STARTUP TIME
(TYPICAL USB APPLICATION)
MAX1693/4 toc18
CH1 = V
OUT
, 5V/div; CH2 = VON, 5V/div;
CH3 = I
OUT
, 500mA/div; CH4 = V
FAULT
, 5V/div
CL = 150µF R
L
= 15
1ms/div
FULL-CURRENT LIMIT CHARGES CAPACITOR
RESISTOR LOAD CURRENT
FOLDBACK­CURRENT LIMIT
3
2
1
MAX1693/4 toc15
MAX1694
OVERCURRENT TO FAULT
AND SWITCH LATCHED OFF
CH1 = V
FAULT
, 5V/div; CH2 = I
OUT
, 5V/div;
CH3 = I
OUT
, 1A/div
2ms/div
MAX1693/(MAX1693H)/MAX1694
USB Current-Limited Switches
with Fault Blanking
_______________________________________________________________________________________ 7
_______________Detailed Description
The MAX1693/(MAX1693H)/MAX1694 P-channel MOS­FET power switches limit output current to 0.7A min to
1.0A max. When the output current is increased beyond the current limit (I
LIMIT
), the current also
increases through the replica switch (I
OUT
/6500). The current-limit error amplifier compares the voltage to the internal 1.24V reference and regulates the current back to the I
LIMIT
.
These switches are not bidirectional; therefore, the input voltage must be higher than the output voltage.
Continuous Short-Circuit Protection
The MAX1693/(MAX1693H)/MAX1694 are foldback short circuit-protected switches. In the event of an out­put short-circuit or current-overload condition, the cur­rent through the switch is foldback-current limited to 500mA continuous for the MAX1693. For the MAX1694, if the short circuit lasts longer than 10ms, the switch is latched off.
Thermal Shutdown
The MAX1693/(MAX1693H)/MAX1694 feature thermal shutdown. The switch turns off and the FAULT output goes low immediately (no fault blanking) when the junc­tion temperature exceeds +165°C. The MAX1694 remains latched with the switch off and the FAULT out- put low. When the MAX1693/(MAX1693H) cools 20°C, the switch turns back on. If the fault short-circuit condi­tion is not removed, the switch will cycle on and off, resulting in a pulsed output.
FAULT
Indicator
The MAX1693/(MAX1693H)/MAX1694 provide a fault output (FAULT). A 100kpullup resistor from FAULT to IN provides a logic control signal. This open-drain out­put goes low when any of the following conditions occur:
The input voltage is below the undervoltage-lockout (UVLO) threshold.
The die temperature exceeds the thermal shutdown temperature limit of +165°C.
The device is in current limit and the 10ms fault­blanking period is exceeded.
Pin Description
NAME FUNCTION
1, 3, 9 IN
Input. P-channel MOSFET source. Connect all IN pins together and bypass with a 1µF ceramic capacitor to ground.
PIN
2, 4, 8, 10 OUT
Switch Output. P-channel MOSFET drain. Connect all OUT pins together and bypass with a
0.1µF capacitor to ground.
5
ON (ON)
Active-Low (High) Switch On Input. A logic low (high) turns the switch on.
6 GND Ground
7
FAULT
Fault-Indicator Output. This open-drain output goes low when the device is in thermal shut­down, undervoltage lockout, or on a sustained (>10ms) current-limit condition. For the MAX1694 only, this output latches low when asserted, and the power switch is turned off until the latch is reset.
Figure 1. MAX1693 Functional Diagram
IN
FAULT
N
P
P
REPLICA AMPLIFIER
OUT
MAX1693
(MAX1693H)
ON
P
ON
CURRENT-LIMIT AMPLIFIER
10ms TIMER
HOT
ON
(ON)
CONTROL
CIRCUITRY
1.24V
GND
MAX1693/(MAX1693H)/MAX1694
USB Current-Limited Switches with Fault Blanking
8 ________________________________________________________________________________________
Fault Blanking
The MAX1693/(MAX1693H)/MAX1694 feature 10ms fault blanking. Fault blanking allows current-limit faults, including momentary short-circuit faults that occur when hot-swapping a capacitive load, and also ensures that no fault is issued during power-up. When a load transient causes the device to enter current limit, an internal counter starts. If the load fault persists beyond the 10ms fault-blanking timeout, the FAULT output asserts low. Ensure that the MAX1693/(MAX1693H)/ MAX1694’s input is adequately bypassed to prevent input glitches from triggering spurious FAULT outputs. Input voltage glitches less than 150mV will not cause a spurious FAULT output. Load-transient faults less than 10ms (typ) will not cause a FAULT output assertion.
Only current-limit faults are blanked. Die overtempera­ture faults and input voltage droops below the UVLO threshold will cause an immediate fault output.
Fault Latching (MAX1694 Only)
The MAX1694 features a latched FAULT output. Whenever the FAULT output is activated, it latches the FAULT output low and also turns the switch off. To clear the latch, either cycle the ON input or cycle the input voltage below UVLO.
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 will be adequate for most applications; however, higher capacitor values will fur­ther reduce the voltage drop at the input (see Figure 2).
Output Capacitor
Connect a 0.1µF capacitor from OUT to GND. This cap­acitor helps prevent inductive parasitics from pulling OUT negative during turn-off.
Layout and Thermal Dissipation
To optimize the switch-response time to output short­circuit conditions, it is very important to keep all traces as short as possible to reduce the effect of undesirable parasitic inductance. Place input and output capacitors as close to the device as possible (no more than 5mm). All IN and all OUT pins must be connected with short traces to the power bus. Wide power bus planes will provide superior heat dissipation through the switch IN and OUT pins. Figure 3 shows suggested pin connec­tions for a single-layer board.
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 (1.0A max) and
RONis the on-resistance of the switch (125mmax).
When the output is short-circuited, foldback-current lim­iting activates and the voltage drop across the switch equals the input supply. The power dissipated across the switch increases, as does the die temperature. If the fault condition is not removed, the thermal-overload-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 will help dissipate additional heat.
Figure 3. IN and OUT Cross Connections for a Single-Layer Board
Figure 2. Typical Application Circuit
Chip Information
TRANSISTOR COUNT: 715
MAX1693
(MAX1693H)
MAX1694
IN OUTPUTOUT
INPUT
2.7V TO 5.5V
FAULT
ON (ON)
ON (OFF)
(ON) OFF
100k
1µF 0.1µF*
*USB SPECIFICATIONS REQUIRE A LARGER CAPACITOR
GND
MAX1693
(MAX1693H)
MAX1694
1
2
3
4
5
IN
OUT
IN
OUT
ON (ON)
OUT
OUT
FAULT
GND
10
IN
9
8
7
6
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 _____________________ 9
© 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
MAX1693/(MAX1693H)/MAX1694
USB Current-Limited Switches
with Fault Blanking
Package Information
Note: Neither the MAX1693/(MAX1693H) nor MAX1694 has an exposed pad.
10LUMAX.EPS
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