19-2663; Rev 2; 2/05
200mA/250mA/300mA Current-Limit Switches
General Description
The MAX4789–MAX4794 family of switches feature
internal current limiting to prevent damage to host
devices due to faulty load conditions. These analog
switches have a low 0.2Ω on-resistance and operate
from 2.3V to 5.5V input voltage range. They are avail-
able with guaranteed 200mA, 250mA, and 300mA cur-
rent limits, making them ideal for SDIO and other load
switching applications.
When the switch is on and a load is connected to the
port, a guaranteed blanking time of 14ms ensures that
the transient voltages settle down. If after this blanking
time the load current is greater than the current limit,
the MAX4789, MAX4791, and MAX4793 enter a latch-
off state where the switch is turned off and
FLAG
is
issued to the microprocessor. The switch can be turned
on again by cycling the power or the ON pin.
The MAX4790, MAX4792, and MAX4794 have an
autoretry feature where the switch turns off after the
blanking time and then continuously checks to see if
the overload condition is present. The switch remains
on after the overload condition disappears.
The MAX4789–MAX4794 are available in 6-pin 3mm x
3mm TDFN and tiny space-saving 4-pin SOT143 pack-
ages. The MAX4789/MAX4791/MAX4793 are also avail-
able in a tiny 5-pin SOT23 package. For lower current
current-limiting switches, refer to the MAX4785–MAX4788
data sheet.
Features
♦
Guaranteed Current Limit: 200mA, 250mA, 300mA
♦
Thermal-Shutdown Protection
♦
Reverse Current Protection
♦
♦
♦
♦
♦
0.2Ω On-Resistance
14ms Guaranteed Blanking Time
FLAG
Function (MAX4789/MAX4791/MAX4793)
80µA Supply Current
8µA Latch-Off Current
(MAX4789/MAX4791/MAX4793)
♦
0.01µA Shutdown Current
♦
2.3V to 5.5V Supply Range
♦
Undervoltage Lockout
♦
Fast Current-Limit Response Time (5µs)
♦
TDFN and SOT23/SOT143 Packages
MAX4789–MAX4794
Ordering Information
PART
MAX4789EUS-T
MAX4789EUK-T
MAX4789ETT
MAX4790EUS-T
MAX4790ETT
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
4 SOT143-4
5 SOT23-5
6 TDFN-EP*
4 SOT143-4
6 TDFN-EP
TOP
MARK
KAFE
AEAC
ABO
KAFF
ABP
Applications
PDAs and Palmtop Devices
Cell Phones
GPS Systems
Hand-Held Devices
SDIO
*EP
= Exposed pad.
Ordering Information continued at end of data sheet.
Selector Guide appears at end of data sheet.
Typical Operating Circuit
2.3V TO 5.5V
Pin Configurations
TOP VIEW
IN
IN
1
GND
2
ON
3
5
OUT
OUT
1
4
IN
ON
µP
MAX4789
MAX4791
MAX4793
MAX4789–
MAX4794
4
FLAG
GND
2
3
ON
MAX4789
MAX4791
MAX4793
GND
FLAG
TO SDIO PORT
OUT
SOT23
SOT143
Pin Configurations continued at end of data sheet.
________________________________________________________________
Maxim Integrated Products
1
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.
200mA/250mA/300mA Current-Limit Switches
MAX4789–MAX4794
ABSOLUTE MAXIMUM RATINGS
IN, ON,
FLAG,
OUT to GND .....................................-0.3V to +6V
OUT Short Circuit to GND .................................Internally Limited
Continuous Power Dissipation (T
A
= +70°C)
4-Pin SOT143 (derate 4.0mW/°C above +70°C)..........320mW
5-Pin SOT23 (derate 7.1mW/°C above +70°C)............571mW
6-Pin TDFN (derate 24.4mW/°C above +70°C).........1951.2mW
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
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
= 2.3V to 5.5V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at V
IN
= 3.3V, T
A
= +25°C.) (Note 1)
PARAMETER
Operating Voltage
Quiescent Current
Latch-Off Current (Note 2)
Shutdown Current
Forward Current Limit
SYMBOL
V
IN
I
Q
I
LATCH
I
SHDN
V
ON
= V
IN
, I
OUT
= 0, V
IN
= +2.3V to +5.0V
switch on
V
IN
= +5.0V to +5.5V
V
ON
= V
IN
, after an overcurrent fault
(MAX4789/MAX4791/MAX4793)
V
ON
= 0V
MAX4789/MAX4790
MAX4791/MAX4792
MAX4793/MAX4794
MAX4789/MAX4790
Reverse Current Limit
ON Input Leakage
Off Switch Leakage
Undervoltage Lockout
Undervoltage Lockout Hysteresis
On-Resistance
ON Input Logic High Voltage
ON Input Logic Low Voltage
FLAG
Output Logic Low Voltage
FLAG
Output High Leakage
Current
Thermal Shutdown
Thermal-Shutdown Hysteresis
DYNAMIC
Turn-On Time (Note 3)
Turn-Off Time (Note 3)
V
ON
from low to high; I
OUT
= 10mA,
C
L
= 0.1µF
V
ON
from high to low; I
OUT
= 10mA,
C
L
= 0.1µF
100
40
µs
ns
R
ON
V
IH
V
IL
I
SINK
= 1mA (MAX4789/MAX4791/MAX4793)
V
IN
= V
FLAG
= 5.5V
(MAX4789/MAX4791/MAX4793)
150
15
T
A
= +25°C, I
OUT
= 100mA
T
A
= -40°C to +85°C, I
OUT
= 100mA
2.0
0.8
0.4
1
UVLO
MAX4791/MAX4792
MAX4793/MAX4794
V
ON
= V
IN
or GND
V
ON
= 0V, V
OUT
= 0V
Rising edge
1.8
100
0.2
0.4
0.5
-1
0.01
200
250
300
CONDITIONS
MIN
2.3
80
TYP
MAX
5.5
120
160
8
0.01
15
1
300
375
450
300
375
450
+1
1
2.2
µA
µA
V
mV
Ω
V
V
V
µA
°C
°C
mA
mA
UNITS
V
µA
µA
µA
2
_______________________________________________________________________________________
200mA/250mA/300mA Current-Limit Switches
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= 2.3V to 5.5V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at V
IN
= 3.3V, T
A
= +25°C.) (Note 1)
PARAMETER
Blanking Time
Short-Circuit Current-Limit
Response Time
Retry Time (Note 4)
t
RETRY
SYMBOL
t
BLANK
CONDITIONS
Overcurrent fault (Figures 2, 3)
V
ON
= V
IN
= 3.3V, short circuit applied to
OUT
MAX4790/MAX4792/MAX4794 (Figure 2)
98
MIN
14
5
420
TYP
MAX
60
UNITS
ms
µs
ms
MAX4789–MAX4794
Note 1:
All parts are 100% tested at +25°C. Limits across the full temperature range are guaranteed by design and correlation.
Note 2:
Latch-off current does not include the current flowing into
FLAG.
Note 3:
The on time is defined as the time taken for the current through the switch to go from 0mA to full load. The off-time is defined
as the time taken for the current through the switch to go from full load to 0mA.
Note 4:
Retry time is typically 7 times the blanking time.
Typical Operating Characteristics
(V
IN
= 3.3V, T
A
= +25°C, unless otherwise noted.)
QUIESCENT SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX4789 toc01
SUPPLY CURRENT
vs. TEMPERATURE
MAX4789 toc02
LATCH-OFF CURRENT
vs. TEMPERATURE
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
-40
V
ON
= V
IN
MAX4789 toc03
100
90
80
SUPPLY CURRENT (µA)
70
60
50
40
30
20
10
0
2.0
2.5
3.0
3.5
4.0
4.5
5.0
V
ON
= V
IN
120
V
ON
= V
IN
100
SUPPLY CURRENT (µA)
80
60
40
20
0
V
IN
= 3.3V
V
IN
= 5V
LATCH-OFF (µA)
V
IN
= 5V
V
IN
= 3.3V
5.5
-40
-15
10
35
60
85
-15
10
35
60
85
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
TEMPERATURE (°C)
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
MAX4789 toc04
SHUTDOWN LEAKAGE CURRENT
vs. TEMPERATURE
MAX4789 toc05
LATCH-OFF LEAKAGE CURRENT
vs. TEMPERATURE
LATCH-OFF LEAKAGE CURRENT (nA)
MAX4789 toc06
100
SHUTDOWN SUPPLY CURRENT (nA)
10
SHUTDOWN LEAKAGE CURRENT (nA)
V
IN
= 5V
100
10
1
0.1
0.01
0.001
V
IN
= 5V
V
IN
= 3.3V
10
V
CC
= 5V
1
1
0.1
V
IN
= 3.3V
0.1
V
CC
= 3.3V
0.01
0.01
0.001
0.001
-40
-15
10
35
60
85
TEMPERATURE (°C)
0.0001
-40
0.0001
-15
10
35
60
85
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
_______________________________________________________________________________________
3
200mA/250mA/300mA Current-Limit Switches
MAX4789–MAX4794
Typical Operating Characteristics (continued)
(V
IN
= 3.3V, T
A
= +25°C, unless otherwise noted.)
NORMALIZED ON-RESISTANCE
vs. TEMPERATURE
MAX4789 toc07
OUTPUT CURRENT
vs. OUTPUT VOLTAGE
450
400
OUTPUT CURRENT (mA)
350
300
250
200
150
100
MAX4793/MAX4794
MAX4789/MAX4790
MAX4791/MAX4792
MAX4789 toc08
1.4
1.2
NORMALIZED R
ON
1.0
V
CC
= 5V
0.8
0.6
0.4
0.2
0
-40
-15
10
35
60
500
50
0
85
0 0.3 0.6 0.9 1.2 1.5 1.8 2.1 2.4 2.7 3.0 3.3
V
IN
- V
OUT
(V)
TEMPERATURE (°C)
SWITCH TURN-ON/OFF TIMES
vs. TEMPERATURE
ON
100
TURN-ON/OFF TIMES (µs)
10
1
0.1
OFF
0.01
I
LOAD
= 10mA
0.001
-40
-15
10
35
60
85
TEMPERATURE (°C)
V
CC
= 3.3V
V
CC
= 5V
MAX4789 toc09
FLAG-BLANKING TIMEOUT
vs. TEMPERATURE
MAX4789 toc10
1000
50
45
FLAG-BLANKING TIME (ms)
40
35
30
25
20
-40
-15
10
35
60
85
TEMPERATURE (°C)
CURRENT-LIMIT RESPONSE
MAX4789 toc11
CURRENT-LIMIT RESPONSE
MAX4789 toc12
V
IN
= 3.3V
C
IN
= 1µF
C
OUT
= 1µF
V
IN
2V/div
V
IN
= V
ON
1V/div
V
ON
2V/div
I
OUT
100mA/div
V
IN
= V
ON
C
IN
= 1µF
C
OUT
= 1µF
20µs/div
I
OUT
100mA/div
40µs/div
4
_______________________________________________________________________________________
200mA/250mA/300mA Current-Limit Switches
Typical Operating Characteristics (continued)
(V
IN
= 3.3V, T
A
= +25°C, unless otherwise noted.)
CURRENT-LIMIT RESPONSE
(OUT SHORTED TO GND)
MAX4789 toc13
MAX4789–MAX4794
SWITCH TURN-ON TIME RESPONSE
MAX4789 toc14
C
IN
= 1µF
C
OUT
= 1µF
V
IN
2V/div
V
ON
1V/div
V
OUT
2V/div
I
OUT
10mA/div
I
OUT
5A/div
40µs/div
100µs/div
SWITCH TURN-OFF TIME RESPONSE
MAX4789 toc15
FLAG-BLANKING RESPONSE
MAX4789 toc16
V
IN
2V/div
V
ON
2V/div
V
ON
2V/div
I
OUT
10mA/div
FLAG
2V/div
I
OUT
100mA/div
200ns/div
4ms/div
Pin Description
PIN
TDFN
MAX4789
MAX4791
MAX4793
1
2
3
4
5
6
TDFN
MAX4790
MAX4792
MAX4794
—
2
3
1, 4
5
6
5-SOT23
MAX4789
MAX4791
MAX4793
4
2
3
—
1
5
4-SOT143
MAX4789–
MAX4794
—
2
3
—
4
1
NAME
FUNCTION
FLAG
GND
ON
N.C.
IN
OUT
Fault Output. This open-drain output goes low when the device stays in
forward or reverse current limit for more than the blanking time period.
FLAG
is high impedance when a fault is not present or when ON is low.
Ground
Active-High Switch On Input. A logic high turns the switch on.
No Connection. Not internally connected.
Input. Bypass with a 0.1µF ceramic capacitor to ground.
Switch Output. Bypass with a 0.1µF ceramic capacitor to ground.
_______________________________________________________________________________________
5
模拟与混合信号
