LTC4415
1
4415fa
Typical applicaTion
FeaTures DescripTion
Dual 4A Ideal Diodes with
Adjustable Current Limit
The LTC
®
4415 contains two monolithic PowerPath ideal
diodes, each capable of supplying up to 4A with typical
forward conduction resistance of 50mΩ. The diode voltage
drops are regulated to 15mV during forward conduction at
low currents, extending the power supply operating range
and ensuring no oscillations during supply switchover.
Less than 1µA of reverse current flows from OUT to IN
making this device well suited for power supply ORing
applications.
The two ideal diodes are independently enabled and
prioritized using inputs EN1 and EN2. The output current
limits can be adjusted independently from 0.5A to 4A
using resistors on the CLIM pins. Furthermore, the ideal
diode currents can be monitored via CLIM pin voltages.
Open-drain status pins indicate when the ideal diodes are
forward conducting. When the die temperature approaches
thermal shutdown, or if the output load exceeds the cur-
rent limit threshold, the corresponding warning pins are
pulled low.
Prioritized Power Supply ORing
applicaTions
n Dual 50mΩ Monolithic Ideal Diodes
n 1.7V to 5.5V Operating Range
n Up to 4A Adjustable Current Limit for Each Diode
n Low Reverse Leakage Current (1µA Max)
n 15mV Forward Drop in Regulation
n Smooth Switchover in Diode ORing
n Load Current Monitor
n Precision Enable Thresholds to Set Switchover
n Soft-Start to Limit Inrush Current on Start-Up
n Status Pins to Indicate Forward Diode Conduction
n Current and Thermal Limit with Warning
n Thermally Enhanced 16-Lead MSOP and DFN
(3mm × 5mm) Packages
n High Current PowerPath™ Switch
n Battery and Wall Adapter Diode ORing
n Backup Battery Diode ORing
n Logic Controlled High Current Power Switch
n Supercapacitor ORing
n Multiple Battery Sharing
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
PowerPath is a trademark of Linear Technology Corporation. All other trademarks are the
property of their respective owners.
IDEAL
IDEAL
LTC4415
GND
EN1
4415 TA01a
4.7µF
TO
LOAD
100k
21.5k
124Ω124Ω
CLIM1
CLIM2
STAT1
WARN1
WARN2
STAT2
EN2
IN2
IN1 OUT1
OUT2
PRIMARY
POWER
SOURCE
SECONDARY
POWER
SOURCE
+
FORWARD VOLTAGE DROP (mV)
0
LOAD CURRENT (A)
3
4
400
4415 TA01b
2
1
0100 200 300 500
CURRENT LIMIT
LTC4415
RON = 50mΩ
SCHOTTKY
DIODE
MBRS410E
Forward Characteristics of LTC4415
vs MBRS410E Schottky
LTC4415
2
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absoluTe MaxiMuM raTings
IN1, IN2, OUT1, OUT2, CLIM1, CLIM2,
STAT1, STAT2, WARN1, WARN2 Voltage ....... –0.3V to 6V
EN1, EN2 Voltage ................. –0.3V to Max (VINx, VOUTx)
Operating Junction Temperature Range
(Notes 3, 4) .............................................–40°C to 125°C
(Note 1)
16
15
14
13
12
11
10
9
17
GND
1
2
3
4
5
6
7
8
OUT1*
OUT1*
STAT1
WARN1
WARN2
STAT2
OUT2*
OUT2*
IN1*
IN1*
EN1
CLIM1
CLIM2
EN2
IN2*
IN2*
TOP VIEW
DHC PACKAGE
VARIATION A
16-LEAD (5mm × 3mm) PLASTIC DFN
TJMAX = 125°C, θJA = 43°C/W
EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB
*ADJACENT PINS ON THE FOUR CORNERS ARE FUSED TOGETHER
1
2
3
4
5
6
7
8
IN1*
IN1*
EN1
CLIM1
CLIM2
EN2
IN2*
IN2*
16
15
14
13
12
11
10
9
OUT1*
OUT1*
STAT1
WARN1
WARN2
STAT2
OUT2*
OUT2*
TOP VIEW
17
GND
MSE PACKAGE
16-LEAD PLASTIC MSOP
TJMAX = 125°C, θJA = 35°C/W TO 40°C/W
EXPOSED PAD (PIN 17) IS GND, MUST BE SOLDERED TO PCB
*ADJACENT PINS ON THE FOUR CORNERS ARE FUSED TOGETHER INTERNALLY.
pin conFiguraTion
orDer inForMaTion
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LTC4415EDHC#PBF LTC4415EDHC#TRPBF 4415 16-Lead (5mm × 3mm) Plastic DFN –40°C to 125°C
LTC4415IDHC#PBF LTC4415IDHC#TRPBF 4415 16-Lead (5mm × 3mm) Plastic DFN –40°C to 125°C
LTC4415EMSE#PBF LTC4415EMSE#TRPBF 4415 16-Lead Plastic MSOP –40°C to 125°C
LTC4415IMSE#PBF LTC4415IMSE#TRPBF 4415 16-Lead Plastic MSOP –40°C to 125°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
Storage Temperature Range .................. –65°C to 150°C
Peak Reflow Temperature ..................................... 260°C
LTC4415
3
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elecTrical characTerisTics
The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at TA = 25°C (Notes 2, 3). VIN1 = VIN2 = 3.6V, RCLIM = 250Ω, unless otherwise
specified.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
VIN1, VOUT1,
VIN2, VOUT2
Operating Supply Range At Least One Input/Output Must Be in This Range l 1.7 5.5 V
VUVLO Undervoltage Lockout VINx Rising
Hysteresis
l1.63
55
1.7 V
mV
IQF Quiescent Current In Forward Regulation
(Note 5)
VIN1 = VEN1 = VEN2 = 3.6V, IOUT1 = –1mA,
VIN2 = VOUT2 = 0V, Measured Through GND Pin
l44 80 µA
IQOFF Quiescent Current In Shutdown VIN1 = VIN2 = VEN2 = 3.6V, VEN1 = 0V,
VOUT1 = VOUT2 = 0V, Measured Through GND Pin
l13 28 µA
IQR(OUT) Reverse Turn-Off Current: OUT1
OUT2
VIN1 = 3.6V, VOUT1 = 3.7V, VIN2 = 3.5V, VOUT2 = 3.6V
(VOUT1 > VOUT2)
l
l
18
5
40
11
µA
µA
IQR(IN) INx Pin Current In Reverse Turn-Off VOUT1 = VOUT2 = 5.5V l 4 10 µA
ILEAK(IN) INx Pin Leakage Current VIN1 = VIN2 = 0V, VOUT1 = VOUT2 = 5.5V –1 1 µA
VFR Forward Regulation Voltage (VINx – VOUTx) IOUTx = –1mA l5 15 25 mV
VRTO Reverse Turn-Off Voltage (VINx – VOUTx)l–50 –30 –10 mV
RFR Forward Dynamic Resistance in
Regulation
IOUTx = –100mA to –300mA 18 30 mΩ
RON On-Resistance in Constant Resistance
Mode
IOUTx = –1A 50 70 mΩ
tON PowerPath Turn-On Time (Notes 6, 7) Before Enable VOUT1 = 1.5V, Diode 1
Before Enable VOUT2 = 1.5V, Diode 2
Before Enable VOUTx = 0V
10
23
250
µs
µs
µs
tON(SD) PowerPath Turn-On from Shutdown
(Note 7)
Both Diodes Disabled and VOUTx = 1.5V Before Enable
Both Diodes Disabled and VOUTx = 0V Before Enable
70
320
µs
µs
tSWITCH PowerPath Switchover Time VINx ↑ (2.6V to 4.6V) to VOUTx Starts Rising, Both
Diodes Enabled, OUT1 and OUT2 Tied Together
9 µs
tOFF PowerPath Turn-Off Time Disable to IIN Falling from 100mA to 1mA 2 µs
tSS Soft-Start Duration (Note 8) VOUTx = 0V 2 ms
Current Monitor
Current Monitor Ratio ICLIMx /IOUTx When IOUTx = –4A
ICLIMx /IOUTx When IOUTx = –2A
0.9
0.8
1
1
1.1
1.2
mA/A
mA/A
Current Limit
VCLIM CLIM Clamp Voltage In Current Limit 0.5 V
ILIM(ADJ) Current Limit Adjustability l0.5 4 A
Accuracy of Adjustable Current Limit
Threshold
VOUTx = VINx – 0.5V, Current Limit = 4A
VOUTx = VINx – 0.5V, Current Limit = 2A
l
l
±8
±15
%
%
ILIM(INT) Internal Current Limit RCLIMx = 0Ω, VOUTx = 0V l4 6 9 A
TWARN Thermal Warning Threshold Rising Temperature
Hysteresis
130
15
°C
°C
TSD Thermal Shutdown Threshold Rising Temperature
Hysteresis
160
20
°C
°C
Open-Drain Status Outputs (STAT1, WARN1, STAT2, WARN2)
VOL Open-Drain Output Low Voltage Current Into Open-Drain Output = 3mA l0.05 0.4 V
Open-Drain Output High Leakage Current Open-Drain Output Voltage = 5.5V l0 1 µA
tSTAT(ON) STAT Turn-On Time (Note 6) EN1 Rising to STAT1 Pull-Down
EN2 Falling to STAT2 Pull-Down
5
18
µs
µs
LTC4415
4
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Typical perForMance characTerisTics
I-V Characteristics On-Resistance vs Temperature On-Resistance vs VIN
TA = 25°C, VIN1 = VIN2 = 3.6V, RCLIM = 250Ω unless otherwise noted.
elecTrical characTerisTics
The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at TA = 25°C (Notes 2, 3). VIN1 = VIN2 = 3.6V, RCLIM = 250Ω, unless otherwise
specified.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
tSTAT(OFF) STAT Turn-Off Time Disable to STAT Pull-Up 2 µs
tWARN(ON) WARN Turn-On Time Current Limit to WARN Pull-Down 500 µs
tWARN(OFF) WARN Turn-Off Time Out of Current Limit to WARN Pull-Up 5 µs
Enable Inputs (EN1, EN2)
VENTH EN1 Rising and EN2 Falling Thresholds l760 800 840 mV
VENHYST EN1 and EN2 Hysteresis 55 mV
Enable Pin Current When Pulled High VEN1 = VEN2 = 3.6V l0 1 µA
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: Unless otherwise specified, current into a pin is positive and
current out of a pin is negative.
Note 3: The LTC4415 is tested under pulsed load conditions such that
TJ ≈ TA. The LTC4415E is guaranteed to meet performance specifications
from 0°C to 85°C. Specifications over the –40°C to 125°C operating
junction temperature range are assured by design, characterization and
correlation with statistical process controls. The LTC4415I is guaranteed
over the full –40°C to 125°C operating junction temperature range.
The junction temperature (TJ in °C) is calculated from the ambient
temperature (TA in °C) and power dissipation (PD in Watts) according to
the formula:
TJ = TA + (PD • θJA)
Note that the maximum ambient temperature consistent with these
specifications is determined by specific operating conditions in
conjunction with board layout, the rated package thermal impedance and
other environmental factors.
Note 4: The LTC4415 includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed 125°C when overtemperature protection is active.
Continuous operation above the specified maximum operating junction
temperature may impair device reliability.
Note 5: One channel enabled. Quiescent current is identical for each
channel.
Note 6: Enable inputs are driven to supply levels. Other diode is already
enabled so the chip bias circuits are active.
Note 7: Turn-on time is measured from enable to IOUTx rising through
1mA. When the output voltage is more than 1.2V, soft-start is disabled and
turn-on is faster.
Note 8: Current ramps from zero to the current limit during the soft-start
duration. Soft-start is measured from 10% to 90% of the current limit. If
the load condition is such that the current does not need to go up to the
current limit during start-up, the output voltage may reach steady state
sooner.
FORWARD VOLTAGE DROP (mV)
0
FORWARD CURRENT (A)
2
3
200
4415 G01
1
050 100 150 250
4
125°C
90°C
25°C
–40°C
RCLIM = 124Ω
TEMPERATURE (°C)
–50
20
R
ON
(mΩ)
30
40
50
60
0 50 100 150
4415 G02
70
80
–25 25 75 125
INPUT VOLTAGE (V)
1
20
R
ON
(mΩ)
30
40
50
60
70
80
2 3 4 5
4415 G03
6
LTC4415
5
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Typical perForMance characTerisTics
Current Limit vs Output Voltage
Quiescent Current
vs Output Current
Current Monitor Ratio vs IOUT
Short-Circuit Current
vs Temperature
Current Monitor Ratio
vs Temperature
Reverse Leakage Current
vs Temperature Quiescent Current vs Temperature Quiescent Current vs VIN
TA = 25°C, VIN1 = VIN2 = 3.6V, RCLIM = 250Ω unless otherwise noted.
TEMPERATURE (°C)
–50
10p
I
LEAK(IN)
(A)
100p
1n
10n
100n
0 50 100 150
4415 G04
1µ
10µ
–25 25 75 125
VIN = 0V
VOUT = 5.5V
VOUT = 3.6V
TEMPERATURE (°C)
–50
QUIESCENT CURRENT (µA)
60
80
100
25 75 150
4415 G05
40
20
0
–25 0 50 100
BOTH DIODES ON
BOTH DIODES OFF (IQOFF)
ONE DIODE ON (IQF)
125
INPUT VOLTAGE (V)
1
QUIESCENT CURRENT (µA)
60
80
100
5
4415 G06
40
20
02346
BOTH DIODES ON
BOTH DIODES OFF (IQOFF)
ONE DIODE ON (IQF)
OUTPUT CURRENT (A)
10
I
QF
(µA)
60
80
100
5
4415 G07
40
20
0234
RCLIM = 124Ω
CURRENT LIMIT
OUTPUT VOLTAGE (V)
0
4
5
7
3
4415 G08
3
2
1 2 4
1
0
6
CURRENT LIMIT (A)
VIN = 3.6V RCLIM = 0Ω
RCLIM = 124Ω
RCLIM = 249Ω
RCLIM = 1000Ω
TEMPERATURE (°C)
–50
SHORT-CIRCUIT CURRENT (A)
4
5
6
25
4415 G09
3
2
–25 0 15050 75 100 125
1
0
7VOUT = 0V
RCLIM = 0Ω
RCLIM = 124Ω
RCLIM = 249Ω
RCLIM = 1000Ω
TEMPERATURE (°C)
–50
0.70
I
CLIM
/I
OUT
(mA/A)
0.80
0.90
1.00
1.20
1.10
1.30
–25 0 25 50
4415 G10
75 100 125 150
IOUT = 2A
RCLIM = 124Ω
DEVICE 2
DEVICE 1 (HIGH RATIO)
DEVICE 3 (LOW RATIO)
OUTPUT CURRENT (A)
0
I
CLIM
/I
OUT
(mA/A)
0.90
1.10
1.00
4
4415 G11
0.80
0.70 123
1.30
1.20
DEVICE 1 (HIGH RATIO)
DEVICE 3 (LOW RATIO)
DEVICE 2
RCLIM = 124Ω
LTC4415
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EN1 Thresholds vs Temperature EN2 Thresholds vs TemperatureUVLO Thresholds vs Temperature
Short-Circuit Response
Short-Circuit Response
at Heavy Load
Switchover in Diode-OR
Application
Load Step Response
Enable and Disable Response for
Large Load Capacitor
Enable and Disable Response for
Small Load Capacitor
Typical perForMance characTerisTics
TA = 25°C, VIN1 = VIN2 = 3.6V, RCLIM = 250Ω unless otherwise noted.
VOUT1
2V/DIV
IIN1
2A/DIV
WARN1
5V/DIV
STAT1
5V/DIV
EN1
5V/DIV
1ms/DIVCOUT1 = 1200µF
RLOAD1 = 8Ω
4415 G12
VOUT1
2V/DIV
IIN1
2A/DIV
WARN1
5V/DIV
STAT1
5V/DIV
EN1
5V/DIV
1ms/DIVCOUT1 = 47µF
RLOAD1 = 8Ω
4415 G13
VIN
0.5V/DIV
VOUT
0.5V/DIV
IIN
2A/DIV
40µs/DIVCOUT = 47µF
RLOAD = 8Ω
RCLIM = 124Ω
4415 G14
3.6V
3.6V
0.1A
3.5A
VIN
5V/DIV
VOUT
5V/DIV
WARN
5V/DIV
IOUT
5A/DIV
100µs/DIVCOUT = 4.7µF
RCLIM = 167Ω
4415 G15
3.6V
10mA
VIN
5V/DIV
VOUT
5V/DIV
IOUT
10A/DIV
40µs/DIVCOUT = 4.7µF
RCLIM = 167Ω
4415 G16
3.6V
1A
1V/DIV
VOUT1,2
1V/DIV
STAT1
5V/DIV
STAT2
5V/DIV
20µs/DIVCOUT = 47µF
RLOAD = 3.6Ω
VOUT1 = VOUT2 (SHORTED)
4415 G17
3.55V
VIN2 = 4.6V
VIN2 = 2.6V
VIN1 = 3.6V
VIN1,
VIN2
TEMPERATURE (°C)
–50
UVLO THRESHOLDS (V)
1.610
1.630
1.650
25 75 150
4415 G18
1.590
1.570
1.550
–25 0 50 100 125
RISING (TURN ON)
FALLING (TURN OFF)
TEMPERATURE (°C)
–50
EN1 THRESHOLDS (V)
0.800
0.850
150
4415 G19
0.750
0.700 050 100
–25 25 75 125
0.900
0.775
0.825
0.725
0.875
RISING (TURN ON)
FALLING (TURN OFF)
TEMPERATURE (°C)
–50
EN2 THRESHOLDS (V)
0.800
0.850
150
4415 G20
0.750
0.700 050 100
–25 25 75 125
0.900
0.775
0.825
0.725
0.875 RISING (TURN OFF)
FALLING (TURN ON)
LTC4415
7
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pin FuncTions
IN1 (Pins 1, 2): Diode 1 Anode and Positive Power Supply
for LTC4415. Bypass IN1 with a ceramic capacitor of at
least 4.7µF. Pins 1 and 2 are fused together on the package.
These pins can be grounded when not used.
EN1 (Pin 3): Enable Input for Diode 1. A high signal greater
than VENTH enables Diode 1.
CLIM1 (Pin 4): Current Limit Adjust and Monitor Pin for
Diode 1. Connect a resistor from CLIM1 to ground to set
the current limit; the diode 1 current can then be monitored
by measuring the voltage on CLIM1 pin. A fixed 6A internal
current limit is active when this pin is shorted to ground.
Do not leave this pin open. Minimize stray capacitance
on this pin to generally less than 200pF (see Applications
Information for more details).
CLIM2 (Pin 5): Current Limit Adjust and Monitor Pin for
Diode 2. Connect a resistor from CLIM2 to ground to set
the current limit; the diode 2 current can then be monitored
by measuring the voltage on CLIM2 pin. A fixed 6A internal
current limit is active when this pin is shorted to ground.
Do not leave this pin open. Minimize stray capacitance
on this pin to generally less than 200pF (see Applications
Information for more details).
EN2 (Pin 6): Enable Input for Diode 2. A low signal less
than VENTH enables Diode 2.
IN2 (Pins 7, 8): Diode 2 Anode and Positive Power Supply
for LTC4415. Bypass IN2 with a ceramic capacitor of at
least 4.7µF. Pins 7 and 8 are fused together on the package.
These pins can be grounded when not used.
OUT2 (Pins 9, 10): Diode 2 Cathode and Output of LTC4415.
Bypass OUT2 with a ceramic capacitor of at least 4.7µF.
Pins 9 and 10 are fused together on the package. Leave
these pins open when not used.
STAT2 (Pin 11): Status Indicator for Diode 2. Open-drain
output pulls down during forward diode conduction. This
pin can be left open or grounded when not used.
WARN2 (Pin 12): Overcurrent and Thermal Warning
Indicator for Diode 2. Open-drain output pulls down when
diode 2 current exceeds its current limit or die temperature
is close to thermal shutdown.
WARN1 (Pin 13): Overcurrent and Thermal Warning
Indicator for Diode 1. Open-drain output pulls down when
diode 1 current exceeds its current limit or die temperature
is close to thermal shutdown.
Power Loss vs Output Current Efficiency vs Output Current
Typical perForMance characTerisTics
TA = 25°C, VIN1 = VIN2 = 3.6V, RCLIM = 250Ω unless otherwise noted.
OUTPUT CURRENT (A)
0
POWER LOSS (W)
0.4
0.6
4
4415 G21
0.2
0123
1.0
0.8
125°C
25°C
–40°C
RCLIM = 124Ω
OUTPUT CURRENT (A)
0
90
EFFICIENCY (%)
91
93
94
95
100
97
12
4415 G22
92
98
99
96
34
125°C
25°C
–40°C
RCLIM = 124Ω
LTC4415
8
4415fa
block DiagraM
GATE
DRIVER
CURRENT
LIMIT
TEMPERATURE
SENSOR
IN1
313
EN1
UVLO1
OUT1 WARN1
4
CLIM1
OUT1
15, 16
1, 2 P1
P2
14
STAT1
GATE
DRIVER
CURRENT
LIMIT
TEMPERATURE
SENSOR
IN2
612
EN2
UVLO2
OUT2 WARN2
5
CLIM2
OUT2
4415 BD
9, 10
7, 8
11
STAT2
IOUT1
1000
IOUT2
1000
pin FuncTions
STAT1 (Pin 14): Status Indicator for Diode 1. Open-drain
output pulls down during forward diode conduction. This
pin can be left open or grounded when not used.
OUT1 (Pins 15, 16): Diode 1 Cathode and Output of
LTC4415. Bypass OUT1 with a ceramic capacitor of at least
4.7µF. Pins 15 and 16 are fused together on the package.
Leave these pins open when not used.
GND (Exposed Pad Pin 17): Device Ground. The exposed
pad must be soldered to PCB ground to provide both
electrical connection to ground and good thermal con-
ductivity to PCB.
LTC4415
9
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operaTion
The LTC4415 consists of two PowerPath ideal diode cir-
cuits within a single package. Each diode in the LTC4415
is capable of supplying a maximum rated output current of
4A from its input supply with typical forward conduction
resistance of 50mΩ.
The diodes are enabled using level-sensitive enable inputs
EN1 and EN2 with opposite polarity to achieve a prioritizer
function with minimal quiescent current during diode-OR
implementation. The enable threshold on the enable pins
(VENTH) is 800mV (typical) with one-sided hysteresis of
55mV (typical). For rising voltage on the EN1 pin, Diode1
is enabled when VEN1 > 800mV (typical), and on the fall-
ing edge it is disabled when VEN1 < 745mV (typical). For
falling voltage on the EN2 pin, Diode 2 is enabled when
VEN2 < 800mV (typical), and on the rising edge it is dis-
abled when VEN1 > 855mV (typical). EN1 or EN2 pin volt-
ages should not exceed the highest voltage on the input
(IN1, IN2) or output (OUT1, OUT2) pins.
Forward conduction of the LTC4415 diodes has three op-
erating ranges as a function of the load current, as shown
in Figure 1 and described below:
1. For small load current, a low forward voltage drop
(VFR = 15mV typical) is maintained by modulating the
series resistance offered by the PFETs (P1/P2) in the
current paths as shown in the Block Diagram. This op-
erating mode is referred to as constant VFR regulation.
In battery-powered and low headroom applications, the
low forward drop of the ideal diodes extend the operat-
ing range beyond that of Schottky diodes.
2. At higher load currents, the LTC4415 gate driver can
no longer modulate the series resistance of the PFETs
(P1/P2) to maintain constant forward drop. This transi-
tion occurs when the gate voltage of the series PFETs
(P1/P2) has been brought down to GND. The ideal
diodes subsequently operate with constant resistance,
RON, between inputs and outputs, IN1/IN2 and OUT1/
OUT2, respectively.
3. As the load current exceeds the current limit, the series
PFETs offer higher resistance between IN1/IN2 and
OUT1/OUT2 by reducing the gate drive in order to limit
the load current; so the forward voltage drop increases
rapidly. This operating mode is referred to as constant
current operation.
When the output of either diode is driven higher than its
input by an alternate supply, conduction through that diode
is suspended to prevent reverse conduction from OUT1/
OUT2 to IN1/IN2. This function allows implementation of
a power supply OR function by simply tying the outputs
OUT1 and OUT2 together.
Current Limit Setting
The output current limit of each diode can be set inde-
pendently by connecting resistors from the current limit
adjust pins CLIM1 and CLIM2 to ground. The current out
of the CLIM1 and CLIM2 pins are 1/1000 of the ideal diode
output currents IOUT1 and IOUT2 respectively. When the
load currents increase so that the CLIM1 or CLIM2 pin
voltages exceeds 0.5V, the LTC4415 detects an overcurrent
condition and regulates the current to a fixed value. The
required value of resistor RCLIM for output current limit
of ILIM is calculated as follows:
RCLIM =1000 •
0.5V
ILIM
The allowed range of RCLIM is 125Ω to 1000Ω unless the
CLIM1/CLIM2 pins are shorted to GND, in which case
the LTC4415 limits the load current using a fixed internal
current limit of 6A.
Overcurrent Status
When either of the ideal diodes is operating in current
limit, the corresponding warning pin, WARN1/WARN2,
is pulled low by an open-drain NFET after a 500µs delay.
Normal operation resumes and the warning pin is released
CONSTANT CURRENT
CONSTANT
RESISTANCE
CONSTANT
VOLTAGE
FORWARD VOLTAGE (V)VFR 4415 F01
CURRENT (A)
ILIM
SLOPE = 1
RON
SLOPE = 1
RFR
Figure 1. Forward Characteristics of LTC4415
LTC4415
10
4415fa
when the load current decreases below the current limit.
Power consumption in LTC4415 increases during opera-
tion in current limit due to the large voltage drop across
the PFET devices (P1 or P2).
Load Current Monitor
The current limit pins output 1/1000th of the ideal diode
output current. The voltage across the current limit resis-
tor can be measured to monitor the current through each
ideal diode as follows:
IOUT =1000 •VCLIM
RCLIM
Note that the current monitor function via VCLIM is not
available when CLIM pins are grounded to use the fixed
internal current limit.
Soft-Start
An internal soft-start is included for each ideal diode to
minimize the start-up inrush current. When either of the
diodes start forward conduction, the load current ramps
from zero to the set current limit over a period of 2ms. The
soft-start can be monitored by observing the CLIM1 and
CLIM2 pin voltages when they are connected to grounded
resistors. Soft-start duration is reduced to 0.5ms (typical)
when the CLIM pins are grounded. In order to minimize
output droop during switchover between input sources
in power supply ORing applications, soft-start is disabled
when the output voltage is above 1.2V.
Forward Conduction Status Monitor
Active low open-drain output status signals, STAT1 and
STAT2, indicate the forward conduction status of each
ideal diode. With resistor pull-ups on these status pins,
a low voltage indicates forward conduction from input to
output, IN1/IN2 to OUT1/OUT2, respectively. The status
pins go to high impedance when the respective ideal diodes
are disabled, during reverse turn-off conditions, or during
thermal shutdown.
Thermal Warning and Shutdown
Thermal sensors within the LTC4415 monitor the die tem-
perature when either of the diodes are enabled. When the
die temperature exceeds the warning threshold (130°C),
the WARN1/WARN2 pins are pulled down with open-drain
NFETs while the LTC4415 continues to operate normally.
This gives some time for the user to reduce the load current
to avoid thermal shutdown. The warning signal is deas-
serted when the die temperature cools down below 115°C.
Thermal shutdown is triggered when the internal die
temperature increases beyond the fault threshold (160°C).
Status pins, STAT1/STAT2, are deasserted during thermal
shutdown to indicate the interruption in forward condi-
tion. Normal operation resumes when the die temperature
cools below 140°C. Note that prolonged operation at the
overtemperature condition degrades device reliability.
Figure 2 shows WARN followed by thermal shutdown
caused by an output short-circuit to ground. Time to
thermal shutdown varies depending on power dissipation,
ambient temperature and board layout. The output cur-
rent ramps up after the device cools down below 140°C,
but shuts down repeatedly as the device overheats due
to persistent short.
operaTion
Figure 2. Current Limit Warning and
Thermal Shutdown on Output Short Circuit
VOUT
2V/DIV
IOUT
2A/DIV
10ms/DIV 4415 F02
VIN = 3.6V
RCLIM = 124Ω
COUT = 4.7µF
STAT
5V/DIV
WARN
5V/DIV
OUTPUT SHORTED
TO GND
RESTART DUE TO
THERMAL HYSTERESIS
THERMAL
SHUTDOWN
The thermal sensors are independent for each diode to
warn of, or shut down the heat generating path so that it
does not hinder the normal operation of the other path.
Depending on the amount of heat generated, the whole
die may still heat up and eventually shut down the other
channel.
LTC4415
11
4415fa
applicaTions inForMaTion
operaTion
Stability Considerations
Any capacitance on the CLIM pins adds a pole to the cur-
rent control loop. Therefore, stray capacitance on these
pins must be kept to a minimum. Although the maximum
allowed value of the current limit adjust resistor is 1000Ω,
any additional capacitance on these pins reduces the
maximum allowed resistance, consequently increasing
the minimum allowed current limit. For stable operation,
the pole frequency at the CLIM pins should be kept above
800kHz. Therefore, if the CLIM pin parasitic capacitance
is CP, the following equation should be used to calculate
the maximum allowed resistor RCLIM:
RCLIM ≤
1
2π•800kHz •CP
When the voltage at the CLIM pins are monitored using a
long cable, such as an oscilloscope probe, decouple the
parasitic capacitance of the probe and the monitor system
using a series resistor as shown in Figure 3, where a 20k
resistor has been added between the CLIM pin and the
probe to ensure stable operation.
Input and Output Capacitors
High current transients through parasitic inductance on the
input and output sides of the ideal diodes can cause volt-
age spikes on the IN1/IN2/OUT1/OUT2 pins. These current
transients can occur on power plug-in, load disconnect
or switching, disable, or even thermal shutdown. Limit
inductance and/or increase bypass capacitors to prevent
pin voltages from exceeding the absolute maximum rat-
ing of 6V. Some ESR in these capacitors may be helpful
in dampening the resonances and minimizing the ringing
caused by hot plugging or load switching. Refer to Ap-
plication Note 88, entitled, “Ceramic Input Capacitors Can
Cause Overvoltage Transients” for a detailed discussion
and mitigation of this phenomenon.
The values of the input and output decoupling capacitors
also depends on the maximum allowable droop during
switchover in power supply ORing applications. Typical du-
ration for LTC4415 ideal diodes to switchover from reverse
turn-off to forward conduction, tSWITCH, is 9µs. Therefore,
the minimum decoupling capacitance, C, required for a
specified maximum output voltage droop, ∆V, when one
of the input voltages drops, can be calculated as follows:
C=
I
LOAD
•t
SWITCH
∆V
where ILOAD is the load current at the time of switchover.
For example, the required value of output capacitance for
a 100mV maximum droop in the output voltage during
quick switchover at 1A load would be 100µF. Note that both
supplies share the load during switchover, and therefore
reduce the droop, when the voltage on the falling supply
pin changes slowly.
Figure 3. Current Monitor with High Capacitance Probe/Instrument
Undervoltage Lockout
Each ideal diode contains an independent UVLO control
circuit so that one input experiencing undervoltage lockout
does not hinder normal operation of the other channel.
The diode conduction path is turned off and the status
signal, STAT1/STAT2, is deasserted during an undervolt-
age condition.
CLIM
PIN
CP
4415 F03
CMONITOR RCLIM
20k
MONITOR
LTC4415
12
4415fa
applicaTions inForMaTion
Board Layout Considerations
When laying out the printed circuit board, the following
checklist should be followed to ensure proper operation
of the LTC4415:
1. Connect the exposed pad of the package (Pin 17) directly
to a large PC board ground to minimize thermal imped-
ance. Correctly soldered to a 2500mm2 double-sided 1oz
copper board, the DFN package has a thermal resistance
(θJA) of approximately 43°C/W. Failure to make good
contact between the exposed pad on the backside of
the package and an adequately sized ground plane re-
sults in much larger thermal resistance, raising the die
temperature for given power dissipation. An example
layout for double layer board is given in Figure 4. Via
holes are used in the board under and near the device
to conduct heat away from the device to the bottom
layer.
2. The traces to the input supplies, outputs and their
decoupling capacitors should be short and wide to
minimize the impact of parasitic inductance. Connect
the GND side of the capacitors directly to the ground
plane of the board. The decoupling capacitors provide
the transient current to the internal power MOSFETs
and their drivers.
3. Minimize the parasitic capacitance on CLIM1 and CLIM2
pins for stable operation.
Figure 4. Example Board Layout for a Double-Sided PCB
EN1
IN1
IN2
OUT1
OUT2
4415 F04
CLIM1
CLIM2
WARN1
WARN2
STAT1
STAT2EN2
LTC4415
13
4415fa
Typical applicaTions
Precision enable inputs and independent status outputs
provide flexibility in power supply back up and load share
applications using the two high current ideal diode circuits
in the LTC4415, as shown in the following examples. The
features shown in these application circuits can be com-
bined in custom applications as needed.
Prioritized Switchover to a Backup Battery
The application circuit, Figure 5, illustrates switchover
from a primary power source to backup power at a pre-
cise input voltage using the prioritized power supply-OR
application circuit. Diode 2 is enabled when the primary
power source voltage on diode 1 input falls below the
threshold given as follows:
VIN1 <0.8V •1+R1+R2
R3
As VIN1 falls further, diode 1 is disabled when the primary
power source voltage falls below the threshold determined
by the resistor divider on enable pin EN1:
VIN1 <0.8V – V
ENHYST
( )
•1+R1
R2+R3
The built-in hysteresis on the enable pins in the LTC4415
provides some overlap of diode enables around the swi-
tchover of power supplies. Resistor R2 can be optionally
used for additional overlap between the two supplies. The
additional overlap is given by:
VOVERLAP ≈V
ENTH •R2
R3 when R2
R3 <<1
The enable overlap minimizes the load voltage droop during
switchover. Both input power supplies provide power to
the load during the overlap. The status output pins can be
pulled up to the output voltage or to a logic power supply.
Automatic Switchover to a Backup Battery and Keep-
Alive Power Source
Figure 6 illustrates an application circuit for automatic
switchover to the backup battery if the primary power
source voltage falls below the backup battery voltage. The
wired-AND of the status outputs is used to drive the gate
of a pair of back-to-back connected external NMOS (M1
and M2) when both primary and backup power sources
are absent or below UVLO or during thermal shutdown of
LTC4415. Under these conditions, the keep-alive source
supplies power to critical components of the system. At
the same time, the wired-AND status output turns off
Figure 5. Prioritized Power Supply ORing
Figure 6. Automatic Switchover to a Backup Battery with Provision
for Keep-Alive Power to the Load When Both Are Absent
IDEAL
IDEAL
LTC4415
GND
EN1 R1
47k
4415 F06
47µF
LOAD
DMN2215UDM
M1
M2
M3
OPTIONAL
KEEP ALIVE/
COIN CELL
CLIM1
CLIM2
STAT1
WARN1
WARN2
STAT2
EN2
IN2
BACKUP
BAT
IN1 OUT1
OUT2
PRIMARY
POWER
SOURCE
+
IDEAL
IDEAL
LTC4415
GND
EN1
4415 F05
4.7µF
TO
LOAD
R1
R2
R3
RCLIM2
470k
RCLIM1
CLIM1
CLIM2
STAT1
WARN1
WARN2
STAT2
EN2
IN2
IN1 OUT1
OUT2
PRIMARY
POWER
SOURCE
SECONDAY
POWER
SOURCE
(BAT)
+
470k
470k
470k
LTC4415
14
4415fa
Typical applicaTions
non-critical high current loads. If the status resistors are
pulled up through the keep-alive power source itself as
shown in Figure 6, the output voltage is limited to:
VOUT = VKEEP_ALIVE – Vgs(M1,2)
where Vgs(M1,2) is the voltage drop from gate to source
of the composite NMOS device (M1 and M2). The pull-up
resistor, R1, consumes power from the keep-alive source
when the primary or backup sources supply power to the
load. The primary power source or backup battery supplies
power to the load when either of them are higher than the
output voltage.
Current limit on any of the diode power paths can be set
to automatically fold back as the output voltage drops (to
reduce power consumption), by switching out a resistor on
the CLIM pin, as shown in Figure 6 for diode 1. The gate
of NMOS M3 can optionally be fed from a resistor divided
output voltage to adjust the output voltage threshold of
current foldback.
Multiple Battery Charging
Figure 7 illustrates an application circuit for automatic dual
battery charging from a single charger. The battery with
lower voltage receives larger charging current until both
battery voltages are equal, then both are charged. While
both batteries are charging simultaneously, the higher
capacity battery gets proportionally higher current from
the charger. For Li-Ion batteries, both batteries achieve
the charger float voltage minus the forward regulation
voltage of 15mV. This concept can be extended to more
than two batteries using additional LTC4415. The STAT1,
STAT2 pins provide information as to when the batteries
are being charged. For intelligent control, the EN1/EN2
input pins can be used with a microcontroller as shown
in Figure 9 later in this section.
Figure 7. Dual Battery Charging from a Single Charger
PROG
EN
FAULT
BATSENS
TO µP
FROM µP
NTC
CHRG
PGND
10µF
PVIN
VINSENSE BAT
IDET TIMER
R4
549Ω
R5
549Ω
C2
0.22µF
C1
10µF
VIN
4.5V TO 5.5V
C3
0.1µF
SS
SW SENSE
LTC4001
L1
1.5µH
GNDSENS
R3
10k
25°C
R2
1k
D1
LED
R1
10k
IDEAL
50k
IDEAL
LTC4415
GND
EN1
4415 F07
CLIM1
CLIM2
STAT1
WARN1
WARN2
STAT2
EN2
IN2
IN1 OUT1
OUT2
BAT2
LOAD2
1.5k
1.5k
+
BAT1
+LOAD1
LTC4415
15
4415fa
Typical applicaTions
Load Sharing by Multiple Batteries and Automatic
Switchover to a Preferred Power Supply
(Such as a Wall Adapter)
An application circuit for dual battery load sharing with
automatic switchover to a wall adapter (when present)
is shown in Figure 8. In the absence of the wall adapter,
the higher voltage battery provides the load current until
it has discharged to the voltage of the other battery. The
load is then shared between the two batteries according
to their capacities, the higher capacity battery providing
proportionally higher current to the load unless limited
by its current limit.
When a wall adapter is applied, the output voltage rises
as the body diode of PFET MP1 conducts and both of the
ideal diode paths in the LTC4415 stop conducting due to
reverse turn-off. At this time, the wired-OR status signal
pulls up the gate voltage of NFET MN1, pulling down the
gate voltage of power PFET MP1, turning it on. The wired-OR
status signal indicates whether the wall adapter or either
of the two batteries is supplying the load current. The two
application circuits described in Figure 7 and Figure 8 can
be cascaded for dual battery charging and load sharing.
Microcontrolled Power Switch with Reverse Blocking,
Selectable Current Limit, Soft-Start and Monitoring
Figure 9 illustrates an application circuit for microcon-
troller monitoring and control of two power sources. The
microcontroller monitors the input supply voltages and
commands the LTC4415 through EN1/EN2 inputs.
Currents through the ideal diodes are monitored by the
microcontroller measuring CLIM1/CLIM2 pin voltages
using ADCs. The current limit can be adjusted for either
diode using an external FET as shown in this application
for diode 1 with MN1. The two ideal diode outputs are
connected together for power source ORing, or they may
feed different loads.
Parallel Diodes for Lower Resistance or Higher
Current Output
The two ideal diodes in the LTC4415 can be connected in
parallel as shown in Figure 10 to achieve a low resistance
PowerPath. The master enable input, ENABLE, turns on
diode 2. EN1 is tied to the output so that diode 1 conducts
only after the output has charged up (by diode 2 according
to its current limit setting). Diode 1 is disabled when the
Figure 8. Dual Battery Load Sharing with Automatic Switchover to a Wall Adapter
IDEAL
IDEAL
LTC4415
GND
EN1
470k
MN1 IRLML2402
CLIM1
CLIM2
STAT1 STAT
WARN1
WARN2
STAT2
EN2
IN2
BAT2
BAT1
IN1 OUT1
OUT2
470k 4.7µF
+
MP1 IRFHS9301
WALL ADAPTER
PVIN1 PVIN2
SW2
SW3
FB2
FB3
VOUT1
LTC3521
SHDN2
SHDN1
1.0M
137k
68.1k
10µF
VIN
4.7µH 4.7µH
VOUT1
3.3V
0.8A
VOUT2
1.8V
0.6A
100k
100k
10µF
4.7µH VOUT3
1.2V
0.6A
221k
4415 F08
SHDN3
PWM
SW1A
SW1B
FB1
PGOOD2
PGOOD1
PGOOD3PGND1A
PGND2GNDPGND1B
ON
OFF
PWM
BURST
+
LTC4415
16
4415fa
Figure 10. Parallel Diodes with Current Limit Foldback and Reverse Polarity Protection
output falls below a threshold set by the resistor divider
on EN1 pin. This arrangement results in current limit
foldback, reducing the current limit of the parallel diodes
to that of only diode 2 when the output voltage falls, thus
controlling power dissipation.
An optional Schottky diode can be inserted in series with
the chip ground as shown in Figure 10 to protect LTC4415
against input power source reverse polarity. The presence
of the Schottky shifts the UVLO and enable pin thresholds
by a voltage equal to the forward voltage drop of the
Schottky diode.
Power Backup Using Supercapacitors and Optional
Keep-Alive Cell
An application of dual backup power is shown on the last
page of this data sheet. Diode 2 provides power to the
triple DC/DC converter (LTC3521) when the primary input
power (VDD) is available, possibly from a wall adapter. When
the input power falls below the supercapacitor voltage,
the supercapcitor provides power to the LTC3521. The
supercapacitor charger (LTC3625) provides a power failure
comparator output signal (PFO) when its input voltage
falls below a preset voltage defined by the resistive divider
on the PFI input. The PFO signal is available to start the
shutdown of high current applications. When the super-
capacitor discharges to a voltage level determined by the
resistor divider on EN1 input of LTC4415, the wired-AND
status signal of LTC4415 pulls up because neither of the
diode paths in LTC4415 are conducting and the coin cell
provides power through a back-to-back connected pair
of NFETs, M1 and M2. The wired-AND status signal is
available to signal that only low current circuits such as
real-time clock or memory remain enabled while operating
from the coin cell.
Figure 9. Microcontrolled PowerPath Monitoring and Control
Typical applicaTions
IDEAL
IDEAL
LTC4415
GND
EN1
MN1
IRLML2402
470k
4415 F09
4.7µF
LOAD
CLIM1
CLIM2
STAT1
WARN1
WARN2
STAT2
EN2
IN2
IN1 OUT1
OUT2
PRIMARY
POWER
SOURCE
AUXILLIARY
POWER
SOURCE
MICRO-
CONTROLLER
IDEAL
IDEAL
LTC4415
GND
EN1 470k
4415 F10
LOAD
CLIM1
CLIM2
STAT1
WARN1
WARN2
STAT2
EN2
IN2
D1
1N5817
IN1 OUT1
OUT2
POWER
SOURCE
ENABLE
LTC4415
17
4415fa
3.00 ±0.10
(2 SIDES)
5.00 ±0.10
(2 SIDES)
NOTE:
1. DRAWING PROPOSED TO BE MADE VARIATION OF VERSION (WJED-1) IN JEDEC
PACKAGE OUTLINE MO-229
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE
TOP AND BOTTOM OF PACKAGE
0.40 ±0.10
1.29 REF
BOTTOM VIEW—EXPOSED PAD
1.65 ±0.10
(2 SIDES)
0.75 ±0.05
R = 0.115
TYP
R = 0.20
TYP
4.40 ±0.10
(2 SIDES)
18
169
PIN 1
TOP MARK
(SEE NOTE 6)
0.200 REF
0.00 – 0.05
(DHC16 Var A) DFN 0410
0.25 ±0.05
PIN 1
NOTCH
0.50 BSC
4.40 ±0.05
(2 SIDES)
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
1.65 ±0.05
(2 SIDES)2.20 ±0.05
0.50 BSC
0.65 ±0.05
1.29 ±0.05
3.50 ±0.05
PACKAGE
OUTLINE
0.25 ± 0.05
DHC Package
16-Lead Plastic DFN (5mm × 3mm)
(Reference LTC DWG # 05-08-1872 Rev Ø)
Variation A
package DescripTion
Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.
LTC4415
18
4415fa
package DescripTion
Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings.
MSOP (MSE16) 0911 REV E
0.53 ±0.152
(.021 ±.006)
SEATING
PLANE
0.18
(.007)
1.10
(.043)
MAX
0.17 –0.27
(.007 – .011)
TYP
0.86
(.034)
REF
0.50
(.0197)
BSC
16
16151413121110
12345678
9
9
18
NOTE:
1. DIMENSIONS IN MILLIMETER/(INCH)
2. DRAWING NOT TO SCALE
3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.
MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX
6. EXPOSED PAD DIMENSION DOES INCLUDE MOLD FLASH. MOLD FLASH ON E-PAD SHALL
NOT EXCEED 0.254mm (.010") PER SIDE.
0.254
(.010) 0° – 6° TYP
DETAIL “A”
DETAIL “A”
GAUGE PLANE
5.23
(.206)
MIN
3.20 – 3.45
(.126 – .136)
0.889 ±0.127
(.035 ±.005)
RECOMMENDED SOLDER PAD LAYOUT
0.305 ±0.038
(.0120 ±.0015)
TYP
0.50
(.0197)
BSC
BOTTOM VIEW OF
EXPOSED PAD OPTION
2.845 ±0.102
(.112 ±.004)
2.845 ±0.102
(.112 ±.004)
4.039 ±0.102
(.159 ±.004)
(NOTE 3)
1.651 ±0.102
(.065 ±.004)
1.651 ±0.102
(.065 ±.004)
0.1016 ±0.0508
(.004 ±.002)
3.00 ±0.102
(.118 ±.004)
(NOTE 4)
0.280 ±0.076
(.011 ±.003)
REF
4.90 ±0.152
(.193 ±.006)
DETAIL “B”
DETAIL “B”
CORNER TAIL IS PART OF
THE LEADFRAME FEATURE.
FOR REFERENCE ONLY
NO MEASUREMENT PURPOSE
0.12 REF
0.35
REF
MSE Package
16-Lead Plastic MSOP, Exposed Die Pad
(Reference LTC DWG # 05-08-1667 Rev E)
LTC4415
19
4415fa
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
revision hisTory
REV DATE DESCRIPTION PAGE NUMBER
A 4/12 Clarified footnotes and added new Note 5 for quiescent current
Changed FET MP1 part number on Figure 8
3, 4
15
LTC4415
20
4415fa
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com
LINEAR TECHNOLOGY CORPORATION 2011
LT 0412 REV A • PRINTED IN USA
relaTeD parTs
Typical applicaTion
Power Backup Using Supercapacitors and Optional Keep-Alive Cell
PART NUMBER DESCRIPTION COMMENTS
LTC4411 2.6A Low Loss Ideal Diode Monolithic Low Loss PowerPath, ThinSOT Package
LTC4412 PowerPath Controller 3V to 28V Input Voltage Range, ThinSOT Package
LTC4413-1/
LTC4413-2
Dual 2.6A, 2.5V to 5.5V, Ideal Diodes in 3mm × 3mm DFN 140mΩ On-Resistance, Overvoltage Protection Sensor with Drive Output
LTC4414 36V, Low Loss PowerPath Controller for Large PFETs Drives Large QG PFETs, 3.5V to 36V
LTC4416 36V, Low Loss Dual PowerPath Controllers Designed to Drive Large and Small QG PFETs, 3.5V to 36V
LTC4352 Low Voltage Ideal Diode Controller With Monitoring Controls Single N-Channel MOSFET, Input Supply Monitors, 2.9V to 18V
LTC4354 Negative High Voltage Diode-OR Controller and Monitor Controls Two N-Channel MOSFETs, 4.5V to 80V
LTC4355 Positive High Voltage Diode-OR Controller and Monitor Controls Two N-Channel MOSFETs, 9V to 80V
LTC4357 Positive High Voltage Ideal Diode Controller Controls Single N-Channel MOSFET, 9V to 80V
LTC4358 5A Monolithic Ideal Diode 20mΩ N-Channel MOSFET, 9V to 26.5V
LTC4066 USB Power Controller and Li-Ion Linear Charger with Low
Loss Ideal Diode
Seamless Transition Between Input Power Sources: Li-Ion Battery,
USB and 5V Wall Adapter
LTC4425 Linear Supercapacitor Charger with Current-Limited Ideal
Diode and V/I Monitor
50mΩ On-Resistance, 2.7V to 5.5V, Programmable Current Limit,
Programmable Output Voltage Mode
LTC2952 Pushbutton Ideal Diode PowerPath Controller with
Supervisor
Controls Two P-Channel MOSFETs, 2.7V to 28V
IDEAL
IDEAL
LTC4415
GND
EN1
M2
CLIM1
CLIM2
STAT1
WARN1
WARN2
STAT2
EN2
IN2
IN1 OUT1
OUT2
125Ω
300k
200k
125Ω
M1
PVIN1 PVIN2
SW2
SW3
FB2
FB3
VOUT1
LTC3521
SHDN2
SHDN1
1.0M
137k
68.1k
10µF
VIN
4.7µH
47k
4.7µH
L1 3.3µH
V
DD
294k
100k
RPROG
78.7k
L2 3.3µH
VOUT1 3.3V 1A
KEEP-ALIVE/COIN CELL
V
OUT2
1.8V
0.6A
100k
100k
10µF
4.7µH V
OUT3
1.2V
0.6A
221k
4415 TA02
SHDN3
PWM
SW1A
SW1B
FB1
PGOOD2
PGOOD1
PGOOD3PGND1A
PGND2GNDPGND1B
ON
OFF
PWM
BURST
47µF
DMN2215UDM
22µF
CTOP
360F
CBOT
360F
SW1
VOUT
SW2
EN
VIN
PFI
VSEL
CTL
GND
GND
VMID
PFO
PROG
LTC3625
