19-1450; Rev 0; 7/99
1.2A, Current-Limited, High-Side
P-Channel Switch with Thermal Shutdown
General Description
The MAX893L smart, low-voltage, P-channel, MOSFET
power switch is intended for high-side load-switching
applications. This switch operates with inputs from
+2.7V to +5.5V, making it ideal for both +3V and +5V
systems. Internal current-limiting circuitry protects the
input supply against overload. Thermal overload pro-
tection limits power dissipation and junction tempera-
ture.
The MAX893L’s maximum programmed current limit is
1.2A. The typical short-circuit current is 1.5 times the
programmed current; therefore, a 1.2A programmed
limit will result in a 1.8A short-circuit current limit. The
current limit through the switch is programmed with a
resistor from SET to ground. The quiescent supply cur-
rent is a low 13µA. When the switch is off, the supply
current decreases to 0.1µA.
The MAX893L is available in an 8-pin SO package.
____________________________Features
o
+2.7V to +5.5V Input Range
o
Programmable Current Limit
0.2A to 1.2A Range
±20% Accuracy
o
1.2A Continuous Load Current
o
1.8A Short-Circuit Current
o
Low Quiescent Current
13µA at V
IN
= 3.3V
0.1µA with Switch Off
o
Thermal Shutdown
o
FAULT
Indicator Output
o
0.07Ω On-Resistance
MAX893L
________________________Applications
USB Ports
USB Hubs
PCMCIA Slots
Access Bus Slots
Portable Equipment
PART
MAX893LESA
Ordering Information
TEMP. RANGE
-40°C to +85°C
PIN-PACKAGE
8 SO
Typical Operating Circuit
Pin Configuration
TOP VIEW
INPUT
IN
IN
100k
FAULT
1µF
GND
ON
SET
R
SET
ON/OFF
IN
2
ON
3
GND
4
OUT
OUTPUT
0.1µF
*
IN
1
8
FAULT
MAX893L
OUT
MAX893L
7
OUT
6
OUT
5
SET
SO
*
USB SPECIFICATIONS REQUIRE HIGHER CAPACITANCE.
________________________________________________________________
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.
1.2A, Current-Limited, High-Side
P-Channel Switch with Thermal Shutdown
MAX893L
ABSOLUTE MAXIMUM RATINGS
IN to GND ................................................................-0.3V to +6V
ON, FAULT
to GND .................................................-0.3V to +6V
SET, OUT to GND ...................................... -0.3V to (V
IN
+ 0.3V)
Maximum Continuous Short-Circuit Switch Current .............2.0A
Continuous Power Dissipation (T
A
= +70°C)
SO (derate 5.88mW/°C above +70°C) .........................471mW
Operating Temperature Range
MAX893LESA ...................................................-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
= 3V,
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
Off-Switch Current
Undervoltage Lockout
On-Resistance
Current-Limit-Amplifier Threshold
Maximum Programmable Continuous
Output Current Limit
Short-Circuit Current
I
OUT
to I
SET
Current Ratio
ON
Input Voltage Low
ON
Input Voltage High
ON
Input Leakage Current
I
SET
Bias Current
FAULT
Logic Output Voltage Low
FAULT
Logic Output High Leakage Current
Slow Current-Loop Response Time
Fast Current-Loop Response Time
Turn-On Time
Turn-Off Time
V
IN
= 5V, I
OUT
= 500mA
V
IN
= 3V, I
OUT
= 500mA
V
IN
= 5V, I
OUT
= 500mA
2
I
OUT
= 500mA, V
OUT
> 1.6V
V
IN
= 2.7V to 5.5V
V
IN
= 2.7V to 3.6V
V
IN
= 4.5V to 5.5V
V
ON
= 5.5V
V
SET
= 1.24V, I
OUT
= 0; V
IN
= V
OUT
I
SINK
= 1mA, V
SET
= 1.4V
V
FAULT
= 5.5V, V
SET
= 1V
20% current overdrive, V
IN
= 5V
0.05
5
2
80
115
4
200
2.0
2.4
0.01
0.5
1
3
0.4
1
920
V
IN
= 5V,
ON
= GND, I
OUT
= 0
ON
= IN, V
IN
= V
OUT
= 5.5V
ON
= IN, V
IN
= 5.5V, V
OUT
= 0
Rising edge, 1% hysteresis
V
IN
= 4.5V
V
IN
= 3.0V
V
SET
required to turn the switch off (Note 1)
1.178
2.0
CONDITIONS
MIN
2.7
13
0.03
0.04
2.4
70
88
1.240
1.2
1.8
1080
1250
0.8
TYP
MAX
5.5
20
1
15
2.6
125
160
1.302
UNITS
V
µA
µA
µA
V
mΩ
V
A
A
A/A
V
V
µA
µA
V
µA
µs
µs
µs
µs
2
_______________________________________________________________________________________
1.2A, Current-Limited, High-Side
P-Channel Switch with Thermal Shutdown
ELECTRICAL CHARACTERISTICS
(V
IN
= 3V,
T
A
= -40°C to +85°C,
unless otherwise noted.) (Note 2)
PARAMETER
Operating Voltage
Quiescent Current
Off-Supply Current
Off-Switch Current
Undervoltage Lockout
On-Resistance
Current-Limit-Amplifier Threshold
I
OUT
to I
SET
Current Ratio
FAULT
Logic Output Voltage Low
Turn-On Time
Turn-Off Time
V
IN
= 5V,
ON
= GND, I
OUT
= 0
ON
= IN, V
IN
= V
OUT
= 5.5V
ON
= IN, V
IN
= 5.5V, V
OUT
= 0
Rising edge, 1% hysteresis
V
IN
= 4.5V
V
IN
= 3.0V
V
SET
required to turn the switch off (Note 1)
I
OUT
= 500mA, V
OUT
> 1.6V
I
SINK
= 1mA, V
SET
= 1.4V
V
IN
= 5V, I
OUT
= 500mA
V
IN
= 5V, I
OUT
= 500mA
1
1.14
865
2.0
CONDITIONS
MIN
3.0
TYP
MAX
5.5
30
2.2
15
2.9
125
160
1.34
1300
0.4
200
20
UNITS
V
µA
µA
µA
V
mΩ
V
A/A
V
µs
µs
MAX893L
Note 1:
Tested with I
OUT
= 100mA and V
SET
raised until V
IN
- V
OUT
≥
0.8V.
Note 2:
Specifications to -40°C are guaranteed by design, not production tested.
_______________________________________________________________________________________
3
1.2A, Current-Limited, High-Side
P-Channel Switch with Thermal Shutdown
MAX893L
__________________________________________Typical Operating Characteristics
(T
A
= +25°C, unless otherwise noted.)
QUIESCENT CURRENT
vs. INPUT VOLTAGE
MAX89L toc01
QUIESCENT CURRENT
vs. TEMPERATURE
V
IN
= 5V
13
QUIESCENT CURRENT (µA)
V
IN
= 3V
12
11
10
9
8
0.001
-40
-20
0
20
40
60
80
100
-40
-20
MAX89L toc02
OFF-SUPPLY CURRENT
vs. TEMPERATURE
MAX893L toc03
14
12
QUIESCENT CURRENT (µA)
10
8
6
4
2
0
0
1
2
3
4
5
6
INPUT VOLTAGE (V)
ON = GND
I
OUT
= 0
14
10
OFF-SUPPLY CURRENT (nA)
1
0.1
0.01
0
20
40
60
80
100
TEMPERATURE (°C)
TEMPERATURE (°C)
OFF-SWITCH CURRENT
vs. TEMPERATURE
MAX893L toc04
NORMALIZED ON-RESISTANCE
vs. TEMPERATURE
MAX893L toc05
I
OUT
/I
SET
RATIO
vs. I
LIMIT
MAX89L toc06
1000
1.3
1.2
NORMALIZED R
ON
1.1
1.0
0.9
0.8
I
OUT
= 1/2 I
LIMIT
V
IN
= 5V
1400
1200
I
OUT
/I
SET
RATIO
1000
800
600
400
200
0
OFF-SWITCH CURRENT (nA)
100
10
1
0.1
0.7
0.01
-40
-20
0
20
40
60
80
100
TEMPERATURE (°C)
0.6
-40
-20
0
20
40
60
80
100
TEMPERATURE (°C)
0
20
40
60
80
100
120
140
I
LIMIT
(%)
NORMALIZED OUTPUT CURRENT
vs. OUTPUT VOLTAGE
MAX893L toc07
TURN-ON TIME
vs. TEMPERATURE
MAX893L toc08
TURN-OFF TIME
vs. TEMPERATURE
I
LOAD
= I
LIMIT
5
4
t
OFF
(µs)
3
2
1
0
-40
-20
0
20
40
60
80
100
TEMPERATURE (°C)
V
IN
= 3V
V
IN
= 5V
MAX893L toc09
1.4
NORMALIZED OUTPUT CURRENT
1.2
1.0
0.8
0.6
0.4
I
LIMIT
= 1.2A
150
140
130
120
t
ON
(µs)
110
100
90
V
IN
= 5V
80
I
LOAD
= I
LIMIT
V
IN
= 3V
6
0.2
V
IN
= 5V
0
0
1
2
3
4
5
6
OUTPUT VOLTAGE (V)
70
60
-40
-20
0
20
40
60
80
100
TEMPERATURE (°C)
4
_______________________________________________________________________________________
1.2A, Current-Limited, High-Side
P-Channel Switch with Thermal Shutdown
____________________________Typical Operating Characteristics (continued)
(T
A
= +25°C, unless otherwise noted.)
MAX893L
OUTPUT OVERLOAD
(SLOW-LOOP RESPONSE)
MAX893L toc10
OUTPUT SHORT CIRCUIT
(FAST-LOOP RESPONSE)
A
MAX893L toc11
A
C
0V
C
V
OUT
0V
B
0A
B
I
OUT
0V
2µs/div
C
IN
= 100µF, C
OUT
= 0.1µF
A: V
IN
, 1V/div, AC-COUPLED
B: I
OUT
, 1A/div
C: V
OUT
, 5V/div
2µs/div
C
IN
= 100µF, C
OUT
= 0.1µF
A: V
IN
, 1V/div, AC-COUPLED
B: I
OUT
, 2A/div
C: V
OUT
, 5V/div
SWITCH TURN-ON TIME
MAX893L toc13
SWITCH TURN-OFF TIME
MAX893L toc14
A
0V
A
0V
B
0V
B
0V
20µs/div
V
IN
= 5V, I
OUT
= I
LIMIT/2
A: V
ON
, 2V/div
B: V
OUT
, 2V/div
1µs/div
V
IN
= 5V, I
OUT
= I
LIMIT/2
A: V
ON
, 2V/div
B: V
OUT
, 2V/div
_______________________________________________________________________________________
5
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