MAX14575ALETA+ [MAXIM]
DPDT, BICMOS, PDSO8,;
| 型号： | MAX14575ALETA+ |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | DPDT, BICMOS, PDSO8, 信息通信管理 光电二极管 |
| 文件： | 总11页 (文件大小：1235K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
MAX14575A/MAX14575AL/
MAX14575B/MAX14575C
250mAto2.5AAdjustableCurrent-LimitSwitches
General Description
Features
S Adjustable Current Limit (250mA to 2500mA)
The MAX14575A/MAX14575AL/MAX14575B/MAX14575C
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 32mI(typ) on-resistance and operate from
a +2.3V to +5.5V input voltage range. The current limit
is adjustable from 250mA to 2.5A, making these devices
ideal for charging a large load capacitor as well as for
high-current load switching applications.
S Accurate ±±0ꢀ ꢁOerload Current Limit (500mA to
2.5A)
S 32mI (typ) Low R
ꢁN
S +2.3V to +5.5V Supply Voltage Range
S ReOerse Current Protection
S Short-Circuit Protection
Each device in the family handles an overcurrent event
differently depending on the option selected. The
MAX14575A/MAX14575AL feature an autoretry mode,
the MAX14575A has active high, and the MAX14575AL
has active-low EN polarity. The MAX14575B has latch-
off mode, and the MAX14575C features a continuous
current-limit mode. Additional safety features include
thermal shutdown protection to prevent overheating and
reverse current blocking to prevent current from being
driven back into the source (see the Selector Guide).
S Thermal Shutdown Protection
S ±30µA (typ) Low Supply Current
S ±µA (max) Shutdown ReOerse Current
S Small, 8-Pin, 2mm x 2mm TDFN Package
Applications
RF Power Amplifier in
Cell Phones
Portable Media Players
UTCA/ATCA Platforms
The MAX14575A/MAX14575AL/MAX14575B/MAX14575C
are available in a small 8-pin, 2mm x 2mm TDFN pack-
age and operate over the -40NC to +85NC extended
temperature range.
USB Ports
SDXC Card Power-Supply
Protection
Data Modem Cards
Ordering Information/Selector Guide
ꢁVERCURRENT
RESPꢁNSE
PART
PIN-PACKAGE
TEMP RANGE
EN PꢁLARITY
TꢁP MARK
MAX±4575AETA+T
MAX±4575ALETA+T
MAX±4575BETA+T
MAX±4575CETA+T
8 TDFN-EP*
8 TDFN-EP*
8 TDFN-EP*
8 TDFN-EP*
Active-High
Active-Low
Active-High
Active-High
Autoretry
BMV
BMW
BMX
BMY
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
Autoretry
Latch-off
Continuous
+Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
*EP = Exposed pad.
Typical Operating Circuit
MAX14575A/MAX14575AL*
MAX14575B/MAX14575C
BIAS
VOLTAGE
IN
OUT
POWER
SUPPLY
LOAD
1µF
1µF
CHARGE
PUMP
SETI
V
PULLUP
CURRENT
REFERENCE
CONTROL
LOGIC
µP
R
SETI
10kΩ
FLAG
EN(EN)*
GND
*() FOR THE MAX14575AL ONLY
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
19-6458; Rev 0; 9/12
MAX14575A/MAX14575AL/
MAX14575B/MAX14575C
250mAto2.5AAdjustableCurrent-LimitSwitches
ABSꢁLUTE MAXIMUM RATINGS
(Voltages referenced to GND.)
Operating Temperature Range.......................... -40NC to +85NC
Storage Temperature Range............................ -65NC to +150NC
Junction Temperature .....................................................+150NC
Lead Temperature (soldering, 10s) ................................+300NC
Soldering Temperature (reflow) ......................................+260NC
IN, EN, EN, FLAG, OUT, and SETI to GND ............-0.3V to +6V
Current into Any Pin (Except IN, OUT) ........................... Q20mA
OUT Short Circuit to GND................................Internally Limited
Continuous Power Dissipation (T = +70NC)
A
TDFN (derate 11.9mW/NC above +70NC) ....................954mW
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.
PACKAGE THERMAL CHARACTERISTICS (Note ±)
TDFN
Junction-to-Ambient Thermal Resistance (B )..... +83.9NC/W
JA
Junction-to-Case Thermal Resistance (B )............. +37NC/W
JC
Note ±: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-lay-
er board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial.
ELECTRICAL CHARACTERISTICS
(V = +2.3V to +5.5V and T = -40NC to +85NC, unless otherwise noted. Typical values are at V = +3.3V, C = 1FF, C
= 1FF,
IN
A
IN
IN
OUT
R
SETI
= 100kI., T = +25°C.) (Note 2)
A
PARAMETER
SYMBꢁL
CꢁNDITIꢁNS
MIN
TYP
MAX
UNITS
SUPPLY ꢁPERATIꢁN
Operating Voltage
V
IN
2.3
5.5
V
I
R
= 0A, switch on, V = 3.3V
IN
OUT
,
Quiescent Current
I
130
6
275
FA
Q
= 560kI
SETI
I
= 0A , after an overcurrent fault
OUT
Latchoff Current
I
20
3.5
1
FA
FA
FA
LATCH
(MAX14575B)
V
V
= 0V, V = 5.5V, V = 5.5V,
EN IN
EN
Shutdown Forward Current
I
0.1
0.07
SHDN
= 0V
OUT
V
V
= 0V, V = 5.5V, V = 0V,
EN IN
EN
Shutdown Reverse Current
INTERNAL FET
I
RSHDN
= 5.5V (current into OUT)
OUT
V
= 5.5V, T = +25°C, I
< I
LIM
= 100mA,
IN
A
OUT
Switch On-Resistance
R
ON
32
50
mI
I
OUT
R
R
R
= 52.65kI
= 268.7kI
= 538.7kI
2250
450
2500
500
250
135
1.35
215
2750
550
SETI
SETI
SETI
Forward Current Limit
I
mA
LIM
200
300
R
R
R
Coefficient
Constant
P
I
I
I
= 0.5A to 2.5A
= 0.5A to 2.5A
kV
kI
kV
SETI
SETI
SETI
LIM
LIM
LIM
C
O I
LIM
Product
= 250mA to 2500mA, V - V = 1V
OUT
172
25
258
2
IN
V
> V + 145mV, after reverse
IN
OUT
Reverse Blocking Current
FA
current-limit shutdown
V
- V = 300mV, OUT falling until
OUT
IN
Reverse Blocking Threshold
V
- V
switch turns on, while measuring
100
345
145
mV
OUT
V
IN
V
- V
IN
OUT
Increase (V - V
asserts, in current-limit mode, V = 3.3V,
R
) drop until FLAG
IN
OUT
FLAG Assertion Drop Voltage
Threshold
mV
FA
IN
SETI = unconnected
2
Maxim Integrated
MAX14575A/MAX14575AL/
MAX14575B/MAX14575C
250mAto2.5AAdjustableCurrent-LimitSwitches
ELECTRICAL CHARACTERISTICS (continued)
(V = +2.3V to +5.5V and T = -40NC to +85NC, unless otherwise noted. Typical values are at V = +3.3V, C = 1FF, C
= 1FF,
IN
A
IN
IN
OUT
R
SETI
= 100kI, T = +25°C.) (Note 2)
A
PARAMETER
SYMBꢁL
CꢁNDITIꢁNS
MIN
TYP
MAX
+1
UNITS
EN, EN INPUT
I
-1
FA
V
EN, EN Input Leakage
EN, EN = IN or GND
LEAK
V
IH
1.6
EN, EN Input Logic-High Voltage
EN, EN Input Logic-Low Voltage
FLAG ꢁUTPUT
V
0.4
V
IL
I
= 1mA
0.4
1
V
FLAG Output Logic-Low Voltage
FLAG Output Leakage Current
TIMING CHARACTERISTICS
SINK
FA
V
= V
= 5.5V, FLAG deasserted
IN
FLAG
Time from ENABLE signal to V
= 90%
= 10%
OUT
Turn-On Time
t
600
Fs
SS
of V , Figure 1
IN
Time from DISABLE signal to V
OUT
Turn-Off Time
t
100
3
Fs
Fs
OFF
of V , R = 1kI, C
= 0 Figure 1
,
IN
L
OUT
Current-Limit Reaction Time
t
Output high and then short circuit applied
LIM
Blanking Time
t
Figures 2 and 3 (Note 3)
10
15
25
ms
ms
BLANK
Retry Time
t
MAX14575A/MAX14575AL Figure 2 (Note 3)
320
500
875
RETRY
THERMAL PRꢁTECTIꢁN
Thermal Shutdown
Thermal Shutdown Hysteresis
+160
20
NC
NC
Note 2: All devices are 100% production tested at T = +25NC. Limits over the operating temperature range are guaranteed by
A
design; not production tested.
Note 3: Blanking time and retry time are generated by the same internal oscillator. The ratio of
t
RETRY
BLANK
is a constant value of 32.
t
EN(EN)*
t
SS
90% V
IN
V
OUT
10% V
IN
t
OFF
*() THE POLARITY OF THE SIGNAL IS REVERSED FOR THE MAX14575AL ONLY.
Figure 1. Timing Diagram for Measuring Turn-On Time (t ) and Turn-Off Time (t
SS
).
OFF
Maxim Integrated
3
MAX14575A/MAX14575AL/
MAX14575B/MAX14575C
250mAto2.5AAdjustableCurrent-LimitSwitches
t
t
t
t
t
t
BLANK
BLANK
RETRY
BLANK
RETRY
BLANK
OUT
CURRENT LIMIT
LOAD CURRENT
THE DEVICE GOES TO
THERMAL-SHUTDOWN MODE
FLAG
Figure 2. Autoretry Fault Diagram
t
t
BLANK
BLANK
OUT
CURRENT LIMIT
LOAD CURRENT
THE DEVICE GOES TO
THERMAL-SHUTDOWN MODE
FLAG
Figure 3. Latchoff Fault Diagram
4
Maxim Integrated
MAX14575A/MAX14575AL/
MAX14575B/MAX14575C
250mAto2.5AAdjustableCurrent-LimitSwitches
Typical Operating Characteristics
(V = +3.3V, C = 1FF, C
= 1FF, R
= 94.2kI, T = +25NC, unless otherwise noted.)
IN
IN
OUT
SETI
A
NORMALIZED CURRENT LIMIT
QUIESCENT SUPPLY CURRENT
vs. SUPPLY VOLTAGE
CURRENT LIMIT vs. SUPPLY VOLTAGE
vs. TEMPERATURE
2.0
1.3
200
190
180
V
= V
IN
EN
1.9
1.8
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1.0
I
= 0A
OUT
1.2
1.1
1.0
0.9
170
160
150
140
130
120
110
100
0.8
0.7
2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5
SUPPLY VOLTAGE (V)
-40
-15
10
35
60
85
85
85
2.0 2.5
3.0 3.5 4.0
4.5 5.0 5.5
TEMPERATURE (°C)
SUPPLY VOLTAGE (V)
QUIESCENT SUPPLY CURRENT
vs. TEMPERATURE
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
SHUTDOWN FORWARD CURRENT
vs. TEMPERATURE
220
200
180
160
140
120
1.0
0.9
0.8
0.7
0.6
0.5
0.4
1.0
0.9
0.8
0.7
0.6
0.5
0.4
V
= V
IN
V
I
= 0V
= 0A
V
= 0V
EN
EN
EN
OUT
I
= 0A
V
OUT
= 0V
OUT
V
= +5V
IN
V
= +5.5V
IN
V
= +5V
IN
V
= +3.3V
IN
0.3
0.2
0.3
0.2
V
= +2.3V
IN
V
= +3.3V
60
IN
0.1
0
0.1
0
100
-40
-15
10
35
85
-40
-15
10
35
60
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
NORMALIZED ON-RESISTANCE
vs. SUPPLY VOLTAGE
SHUTDOWN REVERSE CURRENT
vs. TEMPERATURE
LATCHOFF CURRENT
vs. TEMPERATURE
2.5
2.0
1.0
0.9
0.8
0.7
0.6
0.5
0.4
10
9
V
I
= V
IN
= 100mA
V
V
V
= 0V
MAX14575B
V = V
EN
EN
OUT
EN
= 5.5V
OUT
IN
NORMALIZED TO V = 5.5V AT +25°C
= 2.3V
IN
IN
8
7
1.5
1.0
0.5
6
V
= +5V
IN
5
4
0.3
0.2
3
2
T
A
= +85°C
V
= +3.3V
35
T
A
= +25°C
IN
0.1
0
1
0
T
A
= +40°C
0
2.0 2.5 3.0 3.5 4.0 4.5 5.0 6.5
SUPPLY VOLTAGE (V)
-40
-15
10
35
60
85
-40
-15
10
60
TEMPERATURE (°C)
TEMPERATURE (°C)
Maxim Integrated
5
MAX14575A/MAX14575AL/
MAX14575B/MAX14575C
250mAto2.5AAdjustableCurrent-LimitSwitches
Typical Operating Characteristics (continued)
(V = +3.3V, C = 1FF, C
= 1FF, R = 94.2kI, T = +25NC, unless otherwise noted.)
SETI A
IN
IN
OUT
SWITCH TURN-ON TIME
vs. TEMPERATURE
SWITCH TURN-OFF TIME
vs. TEMPERATURE
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
100
90
80
70
60
50
40
30
20
10
0
I
= 10mA
R = 1kI
L
NO OUTPUT CAPACITOR
OUT
V
= +5V
IN
V
= +5V
IN
V
= 3.3V
IN
V
= 3.3V
IN
-40
-15
10
35
60
85
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
CURRENT-LIMIT RESPONSE
CURRENT-LIMIT RESPONSE
MAX14575A toc12
MAX14575A toc13
SUDDENT SHORT
APPLIED AT
OUTPUT
I
= 200mA
OUT
TO SHORT APPLIED
EN
V
= V = +3.3V
IN
V
= V = +3.3V
IN
EN
V
OUT
V
OUT
2V/div
2V/div
I
OUT
1A/div
I
OUT
1A/div
4ms/div
20ms/div
FLAG RESPONSE
(OVERLOAD CONDITION)
MAX14575A toc14
SHORT TO
GROUND APPLIED
V
= V = +3.3V
IN
EN
V
FLAG
2V/div
I
OUT
1A/div
4ms/div
6
Maxim Integrated
MAX14575A/MAX14575AL/
MAX14575B/MAX14575C
250mAto2.5AAdjustableCurrent-LimitSwitches
Pin Configuration
TOP VIEW
GND EN(EN)** IN
8
IN
5
7
6
MAX14575A
MAX14575AL
MAX14575B
MAX14575C
EP*
+
1
FLAG
2
3
4
SETI
OUT
OUT
TDFN
(2mm × 2mm)
*CONNECT EXPOSED PAD TO GND
**PARENTHESES ARE FOR THE MAX14575AL ONLY
Pin Description
PIN
NAME
FUNCTIꢁN
Open-Drain Overcurrent Indicator Output. FLAG goes low when the overload fault
MAX±4575AL
MAX±4575_
1
1
FLAG duration exceeds the blanking time, reverse current is detected, thermal shutdown
mode is active, or SETI is connected to ground.
Forward Current-Limit Adjust Input. Connect a resistor from SETI to GND to
program the overcurrent limit. If SETI is connected to GND, the switch turns off
and FLAG is asserted. Do not leave SETI unconnected or connect any capacitor
2
2
SETI
larger than 20pF to SETI.
Switch Output. Connect OUT pins 3 and 4 together and bypass OUT to GND with
a 1FF ceramic capacitor as close to the device as possible.
3, 4
5, 6
7
3, 4
5, 6
—
OUT
Power Input. Connect IN pins 5 and 6 together and bypass IN to GND with a 1FF
ceramic capacitor as close to the device as possible. If necessary, use higher
capacitance to prevent large load transients from pulling down the supply voltage.
IN
Active-Low Enable Input. Drive EN low to turn on the switch. Drive EN high to turn
off the switch.
EN
Active-High Enable Input. Drive EN high to turn on the switch. Drive EN low to turn
off the switch.
—
8
7
8
EN
GND
Ground
Exposed Pad. Internally connected to GND. Connect to a large ground plane to
maximize thermal performance. Not intended as an electrical connection point.
—
—
EP
Maxim Integrated
7
MAX14575A/MAX14575AL/
MAX14575B/MAX14575C
250mAto2.5AAdjustableCurrent-LimitSwitches
Functional Diagram
REVERSE-CURRENT
PROTECTION
IN
OUT
THERMAL
SHUTDOWN
MAX14575A
MAX14575AL
MAX14575B
MAX14575C
CONTROL
LOGIC
FLAG
BUFFER
TIMING
CIRCUITRY
BANDGAP
REFERENCE
CURRENT
LIMIT
BUFFER
SETI
EN(EN)*
*PARENTHESES ARE FOR THE MAX14575AL ONLY
before the blanking time (t
) has elapsed. A retry
BLANK
Detailed Description
time delay (t ) starts immediately after the blanking
RETRY
The MAX14575A/MAX14575AL/MAX14575B/MAX14575C
programmable current-limit switches operate from +2.3V
to +5.5V and provide internal current limiting adjust-
able from 250mA to 2.5A. These devices feature a fixed
blanking time and a FLAG output that notifies the proces-
sor when a fault condition is present.
time has elapsed and during that time, the switch latches
off. At the end of t , the switch turns on again. If the
RETRY
fault still exists, the cycle repeats. If the fault has been
removed, the switch stays on. During this cycle, FLAG
stays low. In autoretry, if the die temperature exceeds
+160NC (typ) due to self-heating, the MAX14575A/
MAX14575AL go into thermal-shutdown mode until the
die temperature drops by approximately 20NC.
Programmable Current-Limit Threshold
A resistor from SETI to GND sets the current-limit thresh-
old for the switch (see the Setting the Current-Limit
Threshold section). If the output current is limited at the
current threshold value for a time equal to or longer than
The autoretry feature saves system power in case of
an overcurrent or short-circuit condition. During t
BLANK
time, when the switch is on, the supply current is held at
the current limit. During time t , when the switch is
t
with V - V
higher than the FLAG assertion
BLANK
IN
OUT
RETRY
drop voltage threshold (V
then the FLAG asserts,
FA.),
off, the current through the switch is zero. Thus, the aver-
age output current is much less than the programmed
current limit. Calculate the average output current using
the following equation:
and the MAX14575A/MAX14575AL enter the autoretry
mode, the MAX14575B latches off the switch, and the
MAX14575C enters the continuous current-limit mode.
t
Autoretry (MAX14575A/MAX14575AL)
BLANK
I
= I
×
LOAD LIM
When the forward current reaches the current thresh-
t
+ t
BLANK
RETRY
= 500ms, the
RETRY
old, the t
timer begins counting (Figure 2). FLAG
BLANK
For example, if t
= 15ms and t
BLANK
asserts if the overcurrent condition is present for t
.
BLANK
duty cycle is 3%, resulting in a 97% power savings over
the switch being on the entire time.
The timer resets if the overcurrent condition disappears
8
Maxim Integrated
MAX14575A/MAX14575AL/
MAX14575B/MAX14575C
250mAto2.5AAdjustableCurrent-LimitSwitches
•ꢀ Theꢀreverseꢀcurrentꢀprotectionꢀhasꢀtripped
•ꢀ Theꢀdieꢀtemperatureꢀexceedsꢀ+160NC
•ꢀ SETIꢀisꢀconnectedꢀtoꢀground
Latchoff (MAX14575B)
When the forward current reaches the current thresh-
old, the t
timer begins counting (Figure 3). FLAG
asserts if an overcurrent condition is present for greater
than t time. The timer resets if the overcurrent con-
BLANK
BLANK
dition disappears before t
Thermal Shutdown
has elapsed. The switch
BLANK
Thermal shutdown circuitry protects the devices from
overheating. The switch turns off and FLAG goes low
immediately when the junction temperature exceeds
+160NC (typ). The MAX14575A/AL/C switches turn on
again after the device temperature drops by approxi-
mately 20NC (typ).
turns off if the overcurrent condition continues beyond
the blanking time. Reset the switch by either toggling the
control logic (EN) or cycling the input voltage. If the die
temperature exceeds +160NC (typ) due to self-heating,
the MAX14575B goes into thermal-shutdown mode until
the die temperature drops by approximately 20NC.
Applications Information
Continuous Current Limit (MAX14575C)
When the forward current reaches the forward-current
threshold, the MAX14575C limits the output current to
the programmed current limit. FLAG asserts if the cur-
Setting the Current-Limit Threshold
Connect a resistor between SETI and ground to program
the current-limit threshold value for the MAX14575A/
MAX14575AL/MAX14575B/MAX14575C. Table 2 shows
current-limit thresholds for different resistor values at
SETI. Connecting SETI to ground asserts FLAG.
rent limit is present for t
and deasserts when the
BLANK
overload condition is removed. In this mode, if the die
temperature exceeds +160NC (typ) due to self-heating,
the MAX14575C goes into thermal-shutdown mode until
the die temperature drops by approximately 20NC.
Use the following formula to calculate the current limit:
P(kV)
R
=
− C(kΩ)
SETI(kΩ)
I
(mA)
LIM
Switch Enable Control (EN/EN)
The EN input for the MAX14575A/B/C and EN input for
the MAX14575AL control the internal switch. See Table 1.
Do not use an R
value smaller than 40kI.
SETI
Note: Connecting any capacitor larger than 20pF to SETI
can cause instability.
Reverse Current Protection
The MAX14575A/MAX14575AL/MAX14575B/MAX14575C
feature a reverse current protection circuit that limits the
backflow current to 2FA when the reverse current protec-
tion circuitry has tripped. The switch turns off and FLAG
Table 2. Current-Limit Threshold Os.
Resistor Values
R
SETI
(kω)
CURRENT LIMIT (A)
asserts without waiting for t
to elapse. The switch
BLANK
turns back on and FLAG deasserts when V
drops below the reverse blocking threshold.
- V
OUT
IN
510
0.26
0.28
0.33
0.45
0.51
0.625
0.86
1.32
1.45
1.55
1.75
2.02
2.26
2.5
470
402
301
261
200
150
100
90
FLAG Indicator
FLAG is an open-drain fault indicator output and requires
an external pullup resistor to a DC supply. FLAG goes
low when any of the following conditions occur:
•ꢀ Anꢀovercurrentꢀconditionꢀafterꢀtheꢀblankingꢀtimeꢀhasꢀ
elapsed and V - VOUT > V
IN
FA
Table ±. Switch Truth Table
85
MAX±4575A/B/C
MAX±4575AL
SWITCH
STATUS
75
EN
0
EN
1
64
OFF
ON
57.6
53
1
0
Maxim Integrated
9
MAX14575A/MAX14575AL/
MAX14575B/MAX14575C
250mAto2.5AAdjustableCurrent-LimitSwitches
IN Bypass Capacitor
Connect a minimum 1FF capacitor from IN to GND to
limit the input-voltage drop during momentary output
short-circuit conditions. If the power supply cannot
support the required short-circuit current, then a larger
capacitor should be used to maintain the input voltage
above 2.3V.
Layout and Thermal Dissipation
To optimize the switch response time to output short-
circuit conditions, it is very important to keep all traces
as short as possible to reduce the effect of undesirable
parasitic inductance. Place input and output capacitors
as close as possible to the device (should be no more
than 5mm). IN and OUT must be connected with wide
short traces to the power bus. During normal operation,
the power dissipation is small and the package tem-
perature change is minimal. If the output is continuously
shorted to ground at the maximum supply voltage, the
operation of the switches with the autoretry option does
not cause problems because the total power dissipated
during the short is scaled by the duty cycle:
If the supply is not strong enough and the user does not
want to use a larger capacitor at the input, then the fol-
lowing circuitry can be used (Figure 4.)
OUT Bypass Capacitor
For stable operation over the full temperature range and
over the full programmable current-limit range, use a 1FF
ceramic capacitor from OUT to ground.
V
×I
× t
IN(MAX) OUT(MAX)
BLANK
Excessive output capacitance can cause a false over-
current condition due to decreased dV/dt across the
capacitor. Use the following formula to calculate the
P
=
(MAX)
t
+ t
BLANK
RETRY
Attention must be given to the MAX14575C continuous
current-limit version when the power dissipation during
a fault condition causes the device to reach the thermal-
shutdown threshold.
maximum capacitive load (C ) on OUT:
MAX
I
(mA) × t
(ms)
BLANK(MIN)
LIM
C
(µF) =
MAX
V (V)
IN
For example, for V = 5.0V, t
= 10ms, and I
=
IN
BLANK
LIM
1000mA, C
equals 2000FF.
MAX
Chip Information
PROCESS: BiCMOS
OUT
IN
Package Information
MAX14575A
MAX14575AL
MAX14575B
For the latest package outline information and land patterns
(footprints), go to www.maximintegrated.com/packages. Note
that a “+”, “#”, or “-” in the package code indicates RoHS status
only. Package drawings may show a different suffix character, but
the drawing pertains to the package regardless of RoHS status.
1µF
EN(EN)
SETI
LOAD
MAX14575C FLAG
R
SETI
PACKAGE
TYPE
PACKAGE
CꢁDE
ꢁUTLINE
Nꢁ.
LAND
PATTERN Nꢁ.
GND
EP
8 TDFN-EP
T822+2
2±-0±68
90-0065
~100I*
PARENTHESES FOR THE MAX14575AL ONLY
*IF V > 3V, A DIODE CAN BE USED IN PLACE OF THE RESISTOR.
IN
Figure 4. Optional Protection for Weak Supply
10
Maxim Integrated
MAX14575A/MAX14575AL/
MAX14575B/MAX14575C
250mAto2.5AAdjustableCurrent-LimitSwitches
Revision History
REVISIꢁN REVISIꢁN
PAGES
CHANGED
DESCRIPTIꢁN
NUMBER
DATE
0
9/12
Initial release
—
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied.
Maxim reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical
Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000
11
©
2012 Maxim Integrated Products, Inc.
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
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