MAX14544 Maxim, MAX14544 Datasheet

no-image

MAX14544

Manufacturer Part Number
MAX14544
Description
The MAX14544/MAX14545 are overcurrent detection switches that can provide power to external accessories while preventing the host device from damage due to faulty overload conditions
Manufacturer
Maxim
Datasheet
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.
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.
19-5037; Rev 0; 1/10
Typical Operating Circuit appears at end of data sheet.
Cell Phones
MP3 Players
PDAs
Digital Cameras
eBook
MID
28V-Capable, I
_______________________________________________________________ Maxim Integrated Products 1
General Description
Applications
LIM
V
S
S
S
S
S
S
S
S
S
S
S
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.
BUS
MAX14544ETA+T
MAX14545ETA+T
200mA or 400mA Selectable Current Limit
Output Capable of Withstanding +28V
Reverse-Current Shutdown Protection
+2.3V to +5.5V Input Operation Range
Undervoltage Lockout
Autoretry or Latchoff Option
Thermal Shutdown Protection
0.1µA (typ) Shutdown Current
5µs Fast Current-Limit Detect
8-Pin TDFN (2mm x 2mm) Package
-40NC to +85NC Operating Temperature Range
PART
TOP VIEW
*CONNECT EXPOSED PAD TO GND.
Accessory Switch
GND
ISET
IN
IN
+
1
2
3
4
PIN-
PACKAGE
Ordering Information/
8 TDFN-EP*
8 TDFN-EP*
MAX14544
MAX14545
TDFN
Pin Configuration
Selector Guide
*EP
MARK
TOP
ACY
ACZ
8
7
6
5
Features
OUT
OUT
EN
FLAG
LATCHOFF
Autoretry
RETRY/
Latchoff

Related parts for MAX14544

MAX14544 Summary of contents

Page 1

... 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 ...

Page 2

... 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 ...

Page 3

... OFF 3.3V, output high and then short circuit applied 10FF ceramic, LIM 1FF ceramic OUT 3.3V, Figures 1 and MAX14544, Figure 1 RETRY V = 3.3V 250mA REVERSE t DET ceramic 1FF ceramic OUT 500mV to OUT IN t REC 500mV ...

Page 4

... I CURRENT LIMIT LOAD CURRENT ON SWITCH OFF FLAG ON EN OFF Figure 1. MAX14544 Timing Diagram (Waveforms Not to Scale) CURRENT LIMIT LOAD CURRENT Figure 2. MAX14545 Timing Diagram (Waveforms Not to Scale Accessory Switch LIM BUS BLANK BLANK RETRY t t BLANK BLANK ON SWITCH ...

Page 5

+3.3V 10FF 1FF OUT QUIESCENT SUPPLY CURRENT vs. SUPPLY VOLTAGE 450 400 350 300 250 200 150 100 50 0 2.3 2.7 3.1 3.5 ...

Page 6

... POWER-UP RESPONSE MAX14544/5 toc12 200µs/div 85 CURRENT LIMIT RESPONSE MAX14544/5 toc15 ISET HIGH I OUT 200mA/div V OUT 5V/div V FLAG 5V/div 20ms/div BLANKING TIME MAX14544/5 toc18 MAX14544 ISET HIGH I OUT 200mA/div V OUT 2V/div V FLAG 2V/div 10ms/div V IN 5V/div V OUT 5V/div I OUT 50mA/div ...

Page 7

... Exposed Pad. Connect EP to GND. For enhanced thermal dissipation, connect large copper ground — EP plane. Do not use EP as the sole ground connection. IN UVLO OVLO EN ISET FLAG V Accessory Switch LIM BUS FUNCTION CHARGE PUMP REVERSE CURRENT FORWARD CURRENT MAX14544 MAX14545 Pin Description Functional Diagram OUT CONTROL GND 7 ...

Page 8

... FLAG to the microprocessor. After the retry time elapses, the MAX14544 switch is closed for the duration of the blank- ing time to check if the load current is lower than the limit. Cycle the power or EN input to turn the MAX14545 switch back on ...

Page 9

... FLAG goes low immediately with no fault-blanking time. When IN drops below V (1.8V min), the switch turns off but FLAG stays high. The MAX14544/MAX14545 turns back on when the operating range. Applications Information To limit the input-voltage drop during momentary output short-circuit conditions, connect a capacitor from IN to GND ...

Page 10

... LIM BUS Li+ BATTERY CHARGER VBUS OUT GND IN OUT MAX14544 MAX14545 FLAG V CC NOTE: DRIVE ISET HIGH TO HAVE A 400mA CURRENT LIMIT. EN ISET GND DRIVE ISET LOW TO HAVE A 200mA CURRENT LIMIT. For the latest package outline information and land pat- terns www.maxim-ic.com/packages. Note that a “ ...

Related keywords