19-5037; Rev 0; 1/10
28V-Capable, I
LIM
V
BUS
Accessory Switch
General Description
The MAX14544/MAX14545 are overcurrent detection
switches that can provide power to external accesso-
ries while preventing the host device from damage due
to faulty overload conditions. These analog switches
feature a 270mω (typ) on-resistance and operate from
a +2.3V to +5.5V input voltage range. The selectable
current limit of 200mA or 400mA makes them ideal for
load-switching applications.
The MAX14544 has an autoretry feature, whereas the
MAX14545 has a latchoff feature. When the switch is off,
OUT can withstand 28V maximum. When the switch is on
and a load is connected to the port, a blanking time of
10.5ms ensures that the transient voltage settles down.
After this blanking time, if the voltage across the switch is
greater than the
FLAG
assertion voltage, the switch turns
off and then a
FLAG
is issued to the microprocessor.
After the retry time, the device recloses for the duration
of the blanking time to check if the load current is lower
than the limit. The MAX14544 repeats this cycle if the
overload condition is present. During the cycle,
FLAG
remains asserted. The MAX14544 remains on after the
overload condition is removed and
FLAG
deasserts. For
the MAX14545, after the blanking time, the switch turns
off and then a
FLAG
is issued to the microprocessor. The
switch can be turned on again by cycling the power or
the EN input.
The MAX14544/MAX14545 have additional safety fea-
tures that include thermal shutdown protection, reverse-
current blocking, and overvoltage protection.
The MAX14544/MAX14545 are offered in a space-sav-
ing, 8-pin, 2mm x 2mm TDFN package, and operate over
the -40NC to +85NC extended temperature range.
Features
S
200mA or 400mA Selectable Current Limit
S
Output Capable of Withstanding +28V
S
Reverse-Current Shutdown Protection
S
+2.3V to +5.5V Input Operation Range
S
Undervoltage Lockout
S
Autoretry or Latchoff Option
S
Thermal Shutdown Protection
S
0.1µA (typ) Shutdown Current
S
5µs Fast Current-Limit Detect
S
8-Pin TDFN (2mm x 2mm) Package
S
-40NC to +85NC Operating Temperature Range
MAX14544/MAX14545
Ordering Information/
Selector Guide
PART
MAX14544ETA+T
MAX14545ETA+T
PIN-
PACKAGE
8 TDFN-EP*
8 TDFN-EP*
TOP
MARK
ACY
ACZ
RETRY/
LATCHOFF
Autoretry
Latchoff
Note:
All devices are specified over the -40°C to +85°C tem-
perature range.
+Denotes
a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
*EP
= Exposed pad.
Pin Configuration
TOP VIEW
+
IN
IN
ISET
GND
1
2
3
4
8
7
6
*EP
5
OUT
OUT
EN
FLAG
Applications
Cell Phones
MP3 Players
PDAs
Digital Cameras
eBook
MID
Typical Operating Circuit appears at end of data sheet.
MAX14544
MAX14545
TDFN
*CONNECT EXPOSED PAD TO GND.
_______________________________________________________________
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.
28V-Capable, I
LIM
V
BUS
Accessory Switch
MAX14544/MAX14545
ABSOLUTE MAXIMUM RATINGS
(Voltages referenced to GND.)
OUT .......................................................................-0.3V to +30V
IN,
FLAG,
EN, ISET ..............................................-0.3V to +6.0V
Continuous Power Dissipation (T
A
= +70NC)
8-Pin TDFN (derate 11.9mW/NC above +70NC) ...........953mW
Junction-to-Ambient Thermal Resistance
B
JA
(Note 1) ..............................................................83.9NC/W
Junction-to-Case Thermal Resistance
B
JC
(Note 1) .................................................................37NC/W
Operating Temperature Range .......................... -40NC to +85NC
Storage Temperature Range............................ -65NC to +150NC
Junction Temperature ..................................... -40NC to +150NC
Lead Temperature (soldering, 10s) ................................+300NC
Soldering Temperature (reflow) ......................................+260NC
Note 1:
Package thermal resistances were obtained using the method described in JEDEC specifications. For detailed information
on package thermal considerations, refer to
www.maxim-ic.com/thermal-tutorial.
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
= -40NC to +85NC, unless otherwise noted. Typical values are at V
IN
= +3.3V, T
A
= +25NC.) (Note 2)
PARAMETER
Operating Voltage Range
Undervoltage Lockout
Undervoltage Lockout Hysteresis
IN Overvoltage Trip Level
IN Overvoltage Hysteresis
Quiescent Current
OUT Voltage
I
Q
V
OUT
V
EN
= V
IN
= 3.3V, I
OUT
= 0A
Switch off
V
EN
= V
IN
= 5V, V
OUT
= 5V after an overcur-
rent fault
V
EN
= V
IN
= 5V, V
OUT
= 10V after an overcur-
rent fault
V
EN
= 0V, V
IN
= 5V, V
OUT
= 0V, V
ISET
= 0V
V
EN
= 0V, V
IN
= 5V, V
OUT
= 10V, V
ISET
= 0V
I
OUT
= 100mA, V
IN
= 2.3V
I
OUT
= 100mA, V
IN
> 3.3V
V
ISET
= 0V, V
IN
- V
OUT
= 1V
V
ISET
= V
IN
, V
IN
- V
OUT
= 1V
V
FA
= V
IN
- V
OUT
, where overcurrent is
detected and
FLAG
asserted
V
EN
= V
IN
= 3.3V, V
OUT
rising until reverse-
current shutdown protection trips
After a reverse overcurrent event, V
OUT
falls
below V
IN
until switch turns on, measure
V
IN
- V
OUT
200
400
0.30
0
0.1
0.1
370
270
250
500
0.45
155
0.2
V
OVLO
V
IN
rising
5.5
1
225
380
28
1
FA
3.5
1.1
1.1
600
450
300
600
0.60
350
FA
mI
mA
V
mA
SYMBOL
V
IN
V
UVLO
V
IN
falling
CONDITIONS
MIN
2.3
1.8
100
6.0
TYP
MAX
5.5
2.2
UNITS
V
V
mV
V
%
FA
V
OUT Leakage Current
I
OUTL
IN Shutdown Current
Switch On-Resistance
Current Limit
FLAG
Assertion Voltage
Reverse-Current Detection
Threshold
Reverse-Current Detection
Hysteresis
I
SHDN
R
ON
I
LIM
V
FA
I
DET
100
200
300
mV
2
28V-Capable, I
LIM
V
BUS
Accessory Switch
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= +2.3V to +5.5V, T
A
= -40NC to +85NC, unless otherwise noted. Typical values are at V
IN
= +3.3V, T
A
= +25NC.) (Note 2)
PARAMETER
Input Logic-High Voltage
Input Logic-Low Voltage
Input Leakage
Output Logic-Low Voltage
Output High Leakage Current
Thermal Shutdown
Thermal Shutdown Hysteresis
TIMING CHARACTERISTICS (Note 3)
Turn-On Time
Turn-Off Time
Current-Limit Reaction Time
Blanking Time
Autoretry Time
Reverse-Current Detection Time
Reverse-Current Recovery Time
t
ON
t
OFF
t
LIM
t
BLANK
t
RETRY
t
DET
t
REC
V
EN
from low to high, V
IN
= 3.3V, R
L
= 100I
V
EN
from high to low, V
IN
= 3.3V, R
L
= 100I
V
EN
= V
IN
= 3.3V, output high and then short
circuit applied, C
IN
= 10FF ceramic,
C
OUT
= 1FF ceramic
V
EN
= V
IN
= 3.3V, Figures 1 and 2
MAX14544, Figure 1
V
IN
= 3.3V, I
REVERSE
= 250mA, C
IN
= 10FF
ceramic, C
OUT
= 1FF ceramic
V
OUT
= V
IN
+ 500mV to
V
OUT
= V
IN
- 500mV
4
252
1
5
10.5
661.5
5
0.1
30
1890
0.3
ms
ms
Fs
ms
ms
Fs
ms
SYMBOL
V
IH
V
IL
I
IN
V
OL
V
EN
= V
ISET
= 0V or 5V
I
SINK
= 1mA
V
FLAG
= 5V
V
IN
= 5V
V
IN
= 5V
150
15
-1
CONDITIONS
MIN
1.4
0.4
+1
0.4
1
TYP
MAX
UNITS
V
V
FA
V
FA
NC
NC
MAX14544/MAX14545
3
Note 2:
All devices are production tested at T
A
= +25NC. Specifications over temperature limits are guaranteed by design.
Note 3:
All timing characteristics are measured using 20% and 80% levels.
Medical Electronics
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