19-4814; Rev 0; 7/09
250mA to 1.5A, Adjustable
Current-Limit Switches
General Description
The MAX14523A/MAX14523AL/MAX14523B/MAX14523C
programmable current-limit switches feature internal
current limiting to prevent damage to host devices due
to faulty load conditions. These current-limit switches
feature a low 70mΩ on-resistance and operate from a
+1.7V to +5.5V input voltage range. The current limit is
adjustable from 250mA to 1.5A, making these devices
ideal for SDIO (secure digital input/output) and other
load-switching applications.
Each device in the family handles an overcurrent event
differently depending on the option selected. The
MAX14523A/MAX14523AL go into an autoretry mode,
the MAX14523B latches off the switch, and the
MAX14523C features a continuous current-limit mode.
Additional safety features include thermal shutdown to
prevent overheating and reverse-current blocking to
prevent current from being driven back into the source.
The MAX14523A/MAX14523AL/MAX14523B/MAX14523C
are available in a tiny 8-pin, 3mm x 3mm, TDFN pack-
age and operate over the -40°C to +125°C automotive
temperature range.
♦
Adjustable Current-Limit Threshold
♦
Low-Dropout Voltage (70mV at 1A Load Current)
♦
Short-Circuit Protection
♦
Thermal-Shutdown Protection
♦
Reverse-Current Protection
♦
170µA (typ) Supply Current
♦
Shutdown Reverse Current, 0.6µA (max)
♦
+1.7V to +5.5V Supply Voltage Range
♦
Tiny 8-Pin, 3mm x 3mm, TDFN Package
Features
♦
Accurate (±10%) Overload Current Limit
MAX14523A/MAX14523AL/MAX14523B/MAX14523C
Typical Operating Circuit
BIAS
VOLTAGE
POWER
SUPPLY
IN
1μF
CHARGE
PUMP
OUT
1μF
LOAD
Applications
SDIO Ports
USB Ports
Notebook VGA Ports
GPS
Cell Phones
MP3 Players
UTCA/ATCA Platforms
GND
R
SETI
μP
V
PULLUP
CURRENT
REFERENCE
CONTROL
LOGIC
10kΩ
FLAG
ON(ON)*
N.C.
MAX14523A
MAX14523AL
MAX14523B
MAX14523C
Pin Configuration appears at end of data sheet.
*ON FOR THE MAX14523AL ONLY.
Ordering Information/Selector Guide
PART
MAX14523AATA+
MAX14523ALATA+**
MAX14523BATA+
MAX14523CATA+
PIN-PACKAGE
8 TDFN-EP*
8 TDFN-EP*
8 TDFN-EP*
8 TDFN-EP*
TOP MARK
BLO
BLP
BLQ
BLS
ON POLARTIY
Active-High
Active-Low
Active-High
Active-High
OVERCURRENT RESPONSE
Autoretry
Autoretry
Latch-Off
Continuous
Note:
All devices are specified over the -40°C to +125°C operating temperature range.
+Denotes
a lead(Pb)-free package/RoHs-compliant package.
*EP
= Exposed pad.
**Future
product—contact factory for availability.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
250mA to 1.5A, Adjustable
Current-Limit Switches
MAX14523A/MAX14523AL/MAX14523B/MAX14523C
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to GND.)
IN, ON,
ON, FLAG,
OUT, and SETI to GND .............-0.3V to +6V
Current into Any Pin (Except IN, OUT)................................20mA
Out Short Circuit to GND...................................Internally Limited
Continuous Power Dissipation (T
A
= +70°C) for multilayer board:
8-Pin TDFN (derate 24.4mW/°C above +70°C) .........1952mW
Junction-to-Case Thermal Resistance (θ
JC
)
(Note 1) ...................................................................8.0°C/W
Junction-to-Ambient Thermal Resistance (θ
JA
)
(Note 1) .................................................................41.0°C/W
Operating Temperature Range .........................-40°C to +125°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Note 1:
Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-
layer board. For detailed information on package thermal considerations, refer to
www.maxim-ic.com/thermal-turorial.
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
= +1.7V to +5.5V, R
SETI
= 94.2kΩ, C
IN
= C
OUT
= 1µF, and T
A
= T
J
= -40°C to +125°C, unless otherwise noted. Typical values
are at V
IN
= +3.3V, T
A
= +25°C.) (Note 2)
PARAMETER
SUPPLY OPERATION
Operating Voltage
Quiescent Current
Latchoff Current
Shutdown Forward Current
Shutdown Reverse Current
INTERNAL FET
Switch-On Resistance
Forward-Current Limit
(R
SETI
+2.48k ) × I
LIM
Product
Reverse Blocking Current
Reverse Blocking Threshold
FLAG
Assertion Drop Voltage
Threshold
ON,
ON
INPUT
ON,
ON
Input Leakage
ON,
ON
Input Logic-High Voltage
ON,
ON
Input Logic-Low Voltage
I
LEAK
V
IH
V
IL
V
ON
, V
ON
= V
IN
or V
GND
-1
1.6
0.4
+1
μA
V
V
V
OUT
- V
IN
V
FA
R
ON
I
LIM
V
IN
= 3.3V, I
OUT
lower than I
LIM
R
SETI
= 91.78k , V
IN
- V
OUT
= 1V
R
SETI
= 563.12k , V
IN
- V
OUT
= 1V
I
LIM
= 250mA to 1500mA,
V
IN
- V
OUT
= 1V
V
OUT
> V
IN
+ 140mV, after reverse-current-
limit shutdown
V
OUT
- V
IN
= 300mV, OUT falling until
switch turns on
Increase (V
IN
- V
OUT
) drop until
FLAG
asserts, I
OUT
limiting, V
IN
= 3.3V
40
95
350
1350
225
127.2
70
1500
250
141.4
130
1650
275
155.5
2
140
m
mA
kV
μA
mV
mV
V
IN
I
Q
I
LATCH
I
SHDN
I
RSHDN
I
OUT
= 0A, switch on, V
IN
= 3.3V
V
IN
= 3.3V, I
OUT
= 0A , after an overcurrent
fault (MAX14523B)
V
ON
= 0V, V
ON
= V
IN
, V
IN
= 5.5V, V
OUT
= 0V
V
ON
= 0V, V
ON
= V
IN
, V
IN
= 1.7V, V
OUT
=
5.5V (current into OUT)
1.7
170
10
0.5
0.01
5.5
300
20
7
0.6
V
μA
μA
μA
μA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
2
_______________________________________________________________________________________
250mA to 1.5A, Adjustable
Current-Limit Switches
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= +1.7V to +5.5V, R
SETI
= 94.2kΩ, C
IN
= C
OUT
= 1µF, and T
A
= T
J
= -40°C to +125°C, unless otherwise noted. Typical values
are at V
IN
= +3.3V, T
A
= +25°C.) (Note 2)
PARAMETER
FLAG
OUTPUT
FLAG
Output Logic-Low Voltage
FLAG
Output Leakage Current
DYNAMIC
Turn-On Time
Turn-Off Time
Current-Limit Reaction Time
Blanking Time
Retry Time
THERMAL PROTECTION
Thermal Shutdown
Thermal Shutdown Hysteresis
Low-to-high
+170
15
°C
°C
t
SS
t
OFF
t
LIM
t
BLANK
t
RETRY
Time from ENABLE signal to V
OUT
= 90%
of V
IN
= 3.3V, Figure 1
Time from DISABLE signal to V
OUT
= 10%
of V
IN
= 3.3V, R
L
= 20 , Figure 1
V
IN
= 3.3V, R
SETI
= 91.78k to 563.12k ,
output high and then short-circuit applied
(Note 3)
MAX14523A/MAX14523AL (Note 3)
10
320
1
250
3
14.5
25
875
ms
μs
μs
ms
ms
I
SINK
= 1mA
V
IN
= V
FLAG
= 5.5V,
FLAG
deasserted
0.4
1
V
μA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX14523A/MAX14523AL/MAX14523B/MAX14523C
Note 2:
All devices are 100% tested at 125°C. Electrical limits across the full temperature range are guaranteed by design and correlation.
t
Note 3:
Blanking time and retry time are generated by the same oscillator. Therefore, the ratio of
RETRY
is a constant value of 32.
t
BLANK
See Figures 2 and 3.
ON(ON)*
t
SS
90% V
IN
V
OUT
t
OFF
10% V
IN
*( ) THE POLARITY OF THE SIGNAL IS REVERSED FOR THE MAX14523AL ONLY.
Figure 1. Timing Diagram for Measuring Turn-On Time (t
SS
) and Turn-Off Time (t
OFF
)
_______________________________________________________________________________________
3
250mA to 1.5A, Adjustable
Current-Limit Switches
MAX14523A/MAX14523AL/MAX14523B/MAX14523C
t
BLANK
t
RETRY
t
BLANK
t
RETRY
t
BLANK
t
BLANK
OUT
CURRENT LIMIT
LOAD CURRENT
THE DEVICE GOES TO
THERMAL-SHUTDOWN MODE
FLAG
Figure 2. Autoretry Fault Diagram
t
BLANK
t
BLANK
OUT
CURRENT LIMIT
LOAD CURRENT
THE DEVICE GOES TO
THERMAL-SHUTDOWN MODE
FLAG
Figure 3. Latchoff Fault Diagram
4
_______________________________________________________________________________________
250mA to 1.5A, Adjustable
Current-Limit Switches
Typical Operating Characteristics
(V
IN
= +3.3V, C
IN
= 1µF, C
OUT
= 1µF, R
SETI
= 94.2kΩ, T
A
= +25°C, unless otherwise noted.)
MAX14523A/MAX14523AL/MAX14523B/MAX14523C
CURRENT LIMIT vs. SUPPLY VOLTAGE
MAX14523A toc01
NORMALIZED CURRENT LIMIT
vs. TEMPERATURE
MAX14523A toc02
QUIESCENT SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX14523A toc03
1.60
1.10
300
QUIESCENT SUPPLY CURRENT (μA)
1.55
CURRENT LIMIT (A)
NORMALIZED CURRENT LIMIT
1.05
250
1.50
1.00
200
1.45
0.95
150
1.40
1.70
2.65
3.60
4.55
5.50
SUPPLY VOLTAGE (V)
0.90
-40
-7
26
59
92
125
TEMPERATURE (°C)
100
1.70
2.65
3.60
4.55
5.50
SUPPLY VOLTAGE (V)
QUIESCENT SUPPLY CURRENT
vs. TEMPERATURE
MAX14523A toc04
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
MAX14523A toc05
SHUTDOWN FORWARD CURRENT
vs. TEMPERATURE
SHUTDOWN FORWARD CURRENT (μA)
9
8
7
6
5
4
3
2
1
0
V
IN
= +1.7V
V
IN
= +5.5V
V
ON
= 0V, V
OUT
= 0V
MAX14523A toc06
300
QUIESCENT SUPPLY CURRENT (μA)
10
QUIESCENT SUPPLY CURRENT (μA)
9
8
7
6
5
4
3
2
1
V
ON
= 0V
10
250
V
IN
= +5V
200
V
IN
= +5V
150
V
IN
= +3.3V
100
-40
-7
26
59
92
125
TEMPERATURE (°C)
V
IN
= +3.3V
0
-40
-7
26
59
92
125
TEMPERATURE (°C)
-40
-7
26
59
92
125
TEMPERATURE (°C)
_______________________________________________________________________________________
5
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