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FEATURES

LTC4413-1/LTC4413-2 Dual 2.6A, 2.5V to 5.5V Fast Ideal Diodes in 3mm x 3mm DFN DESCRIPTION
The LTC(R)4413-1 and LTC4413-2 each contain two monolithic ideal diodes, each capable of supplying up to 2.6A from input voltages between 2.5V and 5.5V. The ideal diodes use a 100m P-channel MOSFET to independently connect INA to OUTA and INB to OUTB. During normal forward operation, the voltage drops across each of these diodes are regulated to as low as 18mV. Quiescent current is less than 80A for diode currents up to 1A. If either of the output voltages exceeds its respective input voltage, that MOSFET is turned off and less than 1A of reverse current flows from OUT to IN. Maximum forward current in each MOSFET is limited to a constant 2.6A and internal thermal limiting circuits protect the part during fault conditions. An internal overvoltage protection sensor detects when a voltage exceeds the LTC4413-2 absolute maximum voltage tolerance. Two active-high control pins independently turn off the two ideal diodes contained within the LTC4413-1/LTC4413-2. When the selected channel is reverse biased, or the LTC4413-1/LTC4413-2 is put into low power standby, the status signal is pulled low by an 11A open drain. The LTC4413-1/LTC4413-2 are housed in a 10-lead 3mm x 3mm DFN package.
, LT LTC and LTM are registered trademarks of Linear Technology Corporation. , PowerPath is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners.

2-Channel Ideal Diode OR'ing or Load Sharing Low Loss Replacement for PowerPathTM OR'ing Diodes Fast Response Replacement for LTC4413 Low Forward On Resistance (140m Max at 3.6V) Low Reverse Leakage Current Low Regulated Forward Voltage (18mV Typ) Overvoltage Protection Sensor with Drive Output for an External P-Channel MOSFET (LTC4413-2 Only) 2.5V to 5.5V Operating Range 2.6A Maximum Forward Current Internal Current Limit Protection Internal Thermal Protection Status Output to Indicate if Selected Channel is Conducting Programmable Channel On/Off Low Profile (0.75mm) 10-Lead 3mm x 3mm DFN Package
APPLICATIONS

Battery and Wall Adapter Diode OR'ing in Handheld Products Backup Battery Diode OR'ing Power Switching USB Peripherals Uninterruptable Supplies
TYPICAL APPLICATION
Automatic Switchover from a Battery to a Wall Adapter
FDR8508 WALL ADAPTER INPUT INA 0.1F 1 10F OUTA POWER LOSS (mW) 470k IDEAL ENBA STAT LTC4413-2 GND OVI ENBB INB IDEAL OVP OUTB STAT 500 VCC 700 600
Power Loss vs Load
LTC4413-1 400 300 1N5817 200 100 0 0 500
OVP TO LOAD 4.7F
441312 TA01a
BAT
+
STAT IS HIGH WHEN WALL ADAPTER IS SUPPLYING LOAD CURRENT OVP IS HIGH WHEN WALL ADAPTER VOLTAGE > 6V
1000 1500 2000 LOAD (mA)
2500
3000
441312 TA01b
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LTC4413-1/LTC4413-2 ABSOLUTE MAXIMUM RATINGS
(Note 1)
INA, INB, OUTA, OUTB, STAT, ENBA, ENBB Voltage .................................... -0.3V to 6V OVI, OVP Voltage ....................................... -0.3V to 13V Operating Temperature Range.................. -40C to 85C
Storage Temperature Range................... -65C to 125C Continuous Power Dissipation ..........................1500mW (Derate 25mW/C Above 70C)
PIN CONFIGURATION
TOP VIEW INA ENBA GND ENBB INB 1 2 3 4 5 11 10 OUTA 9 STAT 8 NC 7 NC 6 OUTB INA ENBA GND ENBB INB 1 2 3 4 5 11 TOP VIEW 10 OUTA 9 STAT 8 OVI 7 OVP 6 OUTB
DD PACKAGE 10-LEAD (3mm x 3mm) PLASTIC DFN TJMAX = 125C, JA = 43C/W EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
DD PACKAGE 10-LEAD (3mm x 3mm) PLASTIC DFN TJMAX = 125C, JA = 43C/W EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH LTC4413EDD1#PBF LTC4413EDD2#PBF LEAD BASED FINISH LTC4413EDD1 LTC4413EDD2 TAPE AND REEL LTC4413EDD1#TRPBF LTC4413EDD2#TRPBF TAPE AND REEL LTC4413EDD1#TR LTC4413EDD2#TR PART MARKING LCPP LCPQ PART MARKING LCPP LCPQ PACKAGE DESCRIPTION 10-Lead (3mm x 3mm) Plastic DFN 10-Lead (3mm x 3mm) Plastic DFN PACKAGE DESCRIPTION 10-Lead (3mm x 3mm) Plastic DFN 10-Lead (3mm x 3mm) Plastic DFN TEMPERATURE RANGE -40C to 85C -40C to 85C TEMPERATURE RANGE -40C to 85C -40C to 85C
Consult LTC Marketing for parts specified with wider operating temperature ranges. 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/
ELECTRICAL CHARACTERISTICS
SYMBOL VIN, VOUT UVLO IQF IQRIN IQRGND PARAMETER
The denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. (Notes 2, 6)
CONDITIONS

MIN 2.5
TYP
MAX 5.5 2.45
UNITS V V V A A A
Operating Supply Range for Channel A or B VIN and/or VOUT Must be in This Range for Proper Operation UVLO Turn-On Rising Threshold UVLO Turn-Off Falling Threshold Quiescent Current in Forward Regulation, Measured via GND Current Drawn from or Sourced into IN when VOUT is greater than VIN Quiescent Current While in Reverse Turn-Off, Measured via GND Max (VINA, VINB, VOUTA, VOUTB) Max (VINA, VINB, VOUTA, VOUTB) VINA = 3.6V, IINA = 100mA, VINB = 0V, IINB = 0mA (Note 3) VIN = 3.6V, VOUT = 5.5V (Note 6) VINA = VINB = 0V, VOUTB = VOUTA = 5.5V, VSTAT = 0V
1.7 40 -1 2.5 28 58 4.5 36
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LTC4413-1/LTC4413-2 ELECTRICAL CHARACTERISTICS
SYMBOL IQROUTB PARAMETER Quiescent Current While in Reverse Turn-Off. Current Drawn from VOUTA when OUTB Supplies Chip Power Quiescent Current with Both ENBA and ENBB High Reverse Turn-Off Voltage (VOUT - VIN) Forward Voltage Drop (VIN - VOUT) at IOUT = -1mA On-Resistance, RFWD Regulation (Measured as V/I) On-Resistance, RON Regulation (Measured as V/I at IIN = 1A) PowerPath Turn-On Time PowerPath Turn-Off Time
The denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. (Notes 2, 6)
CONDITIONS VINA = VINB = 0V, VOUTA = 3.6V, VOUTB = 5.5V
MIN
TYP 3.5
MAX 6.5
UNITS A
IQOFF VRTO VFWD RFWD RON tON tOFF
VINA = VINB = 3.6V, VENBA = VENBB = 1V VIN = 3.6V VIN = 3.6V VIN = 3.6V, IOUT = -100mA to -500mA (Note 5) VIN = 3.6V, IIN = 1A (Note 5) VIN = 3.6V, from ENB Falling to IOUT Ramp Starting VIN = 3.6V, from ENB Rising with IIN = 100mA Falling to 0mA VINA OR B = 3.6V (Note 5) VINA OR B = 3.6V, IOUT = 1.8A (Note 5)

28 -5 18 100 140 11 2
38 10 24 140 200
A mV mV m m s s
Short-Circuit Response IOC IQOC STAT Output ISOFF ISON tS(ON) tS(OFF) ENB Inputs VENBIH VENBIL VENBHYST IENB VOVIH VOVIL VOVID IOVI ENB Inputs Rising Threshold Voltage ENB Inputs Falling Threshold Voltage ENB Input Hysteresis ENB Inputs Pull-Down Current OVI Input Rising Threshold Voltage OVI Input Falling Threshold Voltage OVI-OVP Voltage Drop OVI Bias Current VENB Rising VENB Falling VENBHYST = (VENBIH - VENBIL) VOUT < VIN = 3.6V, VENB < VIL VOVI Rising VOVI Falling VOVI = 8V, No Load at OVP VOVI = 8V 5.4

Current Limit Quiescent Current While in Overcurrent Operation STAT Off Current STAT Sink Current STAT Pin Current Turn-On Time STAT Pin Current Turn-Off Time
1.8 100 130
A A
Shut Down VIN > VOUT, VCTL < VIL, TJ < 135C, IOUT < IMAX VIN = 3.6V, from ENB Falling VIN = 3.6V, from ENB Rising

-1 7
0 11 1.8 0.8 540
1 13
A A s s
600
mV mV mV
400 2
460 90 3 5.9 5.6 100 80 4 6.2
A V V mV A
OVI Input (LTC4413-2 Only)
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: The LTC4413-1/LTC4413-2 are guaranteed to meet performance specifications from 0C to 85C. Specifications over the -40C to 85C ambient operating temperature range are assured by design, characterization and correlation with statistical process controls. Note 3: Quiescent current increases with diode current: refer to plot of IQF vs IOUT.
Note 4: This IC includes overtemperature protection that is intended to protect the device during momentary overload conditions. Overtemperature protection will become active at a junction temperature greater than the maximum operating temperature. Continuous operation above the specified maximum operating junction temperature may impair device reliability. Note 5: Specification is guaranteed by correlation to wafer-level measurements. Note 6: Unless otherwise specified, current into a pin is positive and current out of a pin is negative. All voltages referenced to GND.
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LTC4413-1/LTC4413-2 TYPICAL PERFORMANCE CHARACTERISTICS
IQF vs ILOAD (Log)
120 120C 100 80 IQF (A) 60 40 20 0 1 10 100 LOAD (mA) 1000 10000
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IQF vs ILOAD (Linear)
120 120C 100 80 IQF (A) 60 40 20 0 80C 40C 0C IQF (A) -40C 100 80C 40C 0C -40C 120
IQF vs Temperature
1A 80 500mA 60 40 20 0 -40 100mA 1mA
0
500
1000 1500 2000 LOAD (mA)
2500
3000
0
40 80 TEMPERATURE (C)
120
441312 G03
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IQF vs VIN
90 80 70 60 IOC (mA) IQF (A) 50 40 30 20 10 0 2 2.5 3 3.5 4 VIN (V)
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IOC vs Temperature
3500 IQF = 1A 3000 2500 IQF = 100mA 2000 1500 UVLO THRESHOLDS (V) 2.20 2.15 2.10 2.05 2.00
UVLO Thresholds vs Temperature
RISING
FALLING 1.95 1.90 1.85 -40
1000 500 0 -40
4.5
5
5.5
6
0
40 TEMPERATURE (C)
80
120
441312 G05
0
40 TEMPERATURE (C)
80
120
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UVLO Hystersis vs Temperature
250 600 500
ENB Thresholds vs Temperature
120 100 ENB HYSETERSIS (mV) ENBIH ENBIL 80 60 40 20
ENB Hysteresis vs Temperature
UVLO HYSTERESIS (mV)
200 ENBIH/ENBIL (mV) 150
400 300 200 100 0 -40
100
50
0 -40 -20
0
20 40 60 80 TEMPERATURE (C)
100 120
441312 G07
0
40 80 TEMPERATURE (C)
120
441312 G08
0 -40 -20
0
20 40 60 80 TEMPERATURE (C)
100 120
441312 G09
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LTC4413-1/LTC4413-2 TYPICAL PERFORMANCE CHARACTERISTICS
RFWD vs VIN and ILOAD = 500mA
80 78 76 RFWD 500mA (m) 74 RFWD (m) 72 70 68 66 64 62 60 2 2.5 3 3.5 4 4.5 VIN (V) 5 0 5.5 6 0 500 1000 1500 2000 LOAD (mA) 2500 0 3000 0 1 10 100 LOAD (mA) 1000 0 10000
441312 G12
VFWD and RFWD vs ILOAD (Linear)
500 120C 80C 40C 0C -40C 250 600 500 400 RFWD (m) VFWD (mV) 150
RFWD and VFWD vs ILOAD (Log)
120C 80C 40C 0C -40C RFWD 300 200 50 100 VFWD 150 100 50 300 250 200 VFWD (mV)
400
200 VFWD
300
200 RFWD 100
100
441312 G10
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VFWD vs ILOAD (Log)
250 120C 80C 40C 0C -40C RFWD (m) 120 100
RFWD vs Temperature
1
ILEAK vs Temperature at VREVERSE = 5.5V
200
100mA 80 60 40 1A ILEAK (A) 500mA
0.1
VFWD (mV)
150
0.01
5.5V 3.6V
100
0.001
50
20 0 -40
0.0001
0 1 10 100 LOAD (mA) 1000 10000
441312 G13
0
40 80 TEMPERATURE (C)
120
441312 G14
0.00001 -40 -20
0
20 40 60 80 TEMPERATURE (C)
100 120
441312 G15
ILEAK vs VREVERSE
100 10 1 ILEAK (A) 0.1 0.01 120C 80C 40C 0C -40C
Response to 800mA Load Step in <16s
CH1 = IN 100mV/DIV CH2 OUT 100mV/DIV
ENB Turn-On, 30s to Turn On with 180mA Load
CH1 IN 1V/DIV CH3 ENB 1V/DIV CH2 OUT 1V/DIV
CH4 IOUT 200mV/DIV
CH4 IOUT 200mV/DIV
0.001 0.0001 0.00001 0 1 2 3 4 VREVERSE (V) 5 6
441312 G16
4s/DIV
441312 G17
10s/DIV
441312 G18
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LTC4413-1/LTC4413-2 TYPICAL PERFORMANCE CHARACTERISTICS
ENB Turn-Off, 2s to Disconnect IN from 180mA Load
100 CH1 IN 1V/DIV CH2 OUT 1V/DIV CH3 ENB 1V/DIV CH4 IIN 100mV/DIV EFFICIENCY (%) 99 98 POWER LOSS (mW) 97 96 95 94 93 4s/DIV
441312 G19
Efficiency vs Load Current
1000
Power Loss vs Load Current
120C 80C 40C 0C -40C
100
10
92 91 90 1
120C 80C 40C 0C -40C 10 100 LOAD (mA) 1000 10000
441312 G20
1
0 1 10 100 LOAD (mA) 1000 10000
441312 G21
Overvoltage Thresholds vs Temperature (LTC4413-2 Only)
6.4 6.2 6.0 5.8 5.6 5.4 5.2 5.0 -40 OVP HYSTERESIS (mV) OVP RISING 400 350 300
Overvoltage Hysteresis vs Temperature (LTC4413-2 Only)
140 120 100 IOVI (A) 80 60 40 20 0 0 40 TEMPERATURE (C) 80 120
441312 G23
OVI Current vs Voltage (LTC4413-2 Only)
TA = 25C
OVPIH/OVPIL (V)
250 200 150 100 50
OVP FALLING
0
40 TEMPERATURE (C)
80
120
441312 G22
0 -40
0
2
4
8 6 VOVI (V)
10
12
441312 G24
OVI-OVP Voltage Drop vs OVI Voltage (LTC4413-2 Only)
6 5 140 4 IQ OVI (A) OVP (V) 3 2 1 20 0 0 2 4 8 6 OVI (V) 10 12
441312 G25
IQ OVI vs Temperature (LTC4413-2 Only)
180 160 IQ OVI = 13V 160 140
OVI-OVP vs Temperature (LTC4413-2 Only)
TA = 25C
VOHOVP = 13V 120 OVI-OVP (mV) 100 80 60 40 20 VOHOVP = 6.5V
120 100 80 60 40 IQ OVI = 6.5V
0 -40
0
40 TEMPERATURE (C)
80
120
441312 G26
0 -40 -20
0
20 40 60 80 TEMPERATURE (C)
100 120
441312 G27
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LTC4413-1/LTC4413-2 PIN FUNCTIONS
INA (Pin 1): Primary Ideal Diode Anode and Positive Power Supply for LTC4413-1/LTC4413-2. Bypass INA with a ceramic capacitor of at least 1F (Series 1 snub resistors . and higher valued capacitances are recommended when large inductances are in series with this input.) This pin can be grounded when not used. Limit slew rate on this pin to less than 2.5V/s. ENBA (Pin 2): Enable Low for Diode A. Pull this pin high to shut down this power path. Tie to GND to enable. Refer to Table 1 for mode control functionality. This pin can be left floating, a weak (3.5A) pull-down internal to LTC4413-1/LTC4413-2 is included. GND (Pin 3): Power Ground for the IC. ENBB (Pin 4): Enable Low for Diode B. Pull this pin high to shut down this power path. Tie to GND to enable. Refer to Table 1 for mode control functionality. This pin can be left floating, a weak (3.5A) pull-down internal to LTC4413-1/LTC4413-2 is included. INB (Pin 5): Secondary Ideal Diode Anode and Positive Power Supply for LTC4413-1/LTC4413-2. Bypass INB with a ceramic capacitor of at least 1F (Series 1 snub resistors . and higher valued capacitances are recommended when large inductances are in series with this input.) This pin can be grounded when not used. Limit slew rate on this pin to less than 2.5V/s. OUTB (Pin 6): Secondary Ideal Diode Cathode and Output of the LTC4413-1/LTC4413-2. Bypass OUTB with a high (1m min) ESR ceramic capacitor of at least 4.7F This . pin must be left floating when not in use. Limit slew rate on this pin to less than 2.5V/s. OVP (Pin 7, LTC4413-2 Only): Drive Output for an External OVP Switch PMOS Transistor (To Inhibit Overvoltage Wall Adapter Voltages from Damaging Device.) During overvoltage conditions, this output will remain high so long as an overvoltage condition persists. This pin must be left floating when not in use. OVI (Pin 8, LTC4413-2 Only): Sense Input for Overvoltage Protection Block. This pin can be left floating or grounded when not used. STAT (Pin 9): Status Condition Indicator. Weak (11A) pull-down current output. When terminated, high indicates diode conducting. Refer to Table 2 for the operation of this pin. This pin can also be left floating or grounded. OUTA (Pin 10): Primary Ideal Diode Cathode and Output of the LTC4413-1/LTC4413-2. Bypass OUTA with a high (1m min) ESR ceramic capacitor of at least 4.7F This . pin must be left floating when not in use. Limit slew rate on this pin to less than 2.5V/s. Exposed Pad (Pin 11): Signal Ground. This pin must be soldered to PCB ground to provide both electrical contact to ground and good thermal contact to PCB.
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LTC4413-1/LTC4413-2 BLOCK DIAGRAM
1
INA
OUTA
10
VOFF ENA
0.5V 2 ENBA
3A
3
GND
5
INB
0.5V 4 ENBB
ENB
BENA
+-
B
6V
3A
8
- +
VOFF
+ -
+ -
OVER CURRENT
-+
+ -
+ -
OVER CURRENT
-+
PA UVLO ENA ENB OUTA (MAX) OUTB (MAX) OVER TEMP
AENA
VGATEA AENA A
OVER TEMP STB
BENA STAT 9
+ - + -
+-
11A
OUTB
6
PB LTC4413-2 ONLY OVERVOLTAGE PROTECTION OVI VGATEB OVP
8 7
441312 BD
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LTC4413-1/LTC4413-2 OPERATION
The LTC4413-1/LTC4413-2 are described with the aid of the Block Diagram. Operation begins when the power source at VINA or VINB rises above the undervoltage lockout (UVLO) voltage of 2.4V and the corresponding control pin ENBA or ENBB is low. If only the voltage at the VINA pin is present, the internal power source (VDD) is supplied from the VINA pin. The amplifier (A) pulls a current proportional to the difference between VINA and VOUTA from the gate (VGATEA) of the internal PFET (PA), driving this gate voltage below VINA. This turns on PA. As VOUTA pulls up to a forward voltage drop (VFWD) of 15mV below VINA, the LTC4413 regulates VGATEA to maintain the small forward voltage drop. The system is now in forward regulation and the load at VOUTA is powered from the supply at VINA. As the load current varies, VGATEA is controlled to maintain VFWD until the load current exceeds the transistor's (PA) ability to deliver the current as VGATEA approaches GND. At this point, the PFET behaves as a fixed resistor, RON, whereby the forward voltage increases slightly with increased load current. As the magnitude of IOUT increases further, (such that ILOAD > IOC) the LTC4413-1/LTC4413-2 fixes the load current to the constant value IOC to protect the device. The characteristics for parameters RFWD, RON, VFWD and IOC are specified with the aid of Figure 1, illustrating the LTC4413-1/LTC4413-2 forward voltage drop versus that of a Schottky. If another supply is provided at VINB, the LTC4413-1/ LTC4413-2 likewise regulate the gate voltage on PB to
IOC LTC4413-1 LTC4413-2 SLOPE: 1/RON CURRENT (A) IFWD 1N5817 SLOPE: 1/RFWD
maintain the output voltage, VOUTB, just below the input voltage VINB. If this alternate supply, VINB, exceeds the voltage at VINA, the LTC4413-1/LTC4413-2 selects this input voltage as the internal supply (VDD). This second ideal diode operates independently of the first ideal diode function. When an alternate power source is connected to the load at VOUTA (or VOUTB), the LTC4413-1/LTC4413-2 sense the increased voltage at VOUTA, and amplifier A increases the voltage VGATEA, reducing the current through PA. When VOUTA is higher than VINA + VRTO, VGATEA will be pulled up to VDD, turning off PA. The internal power source for the LTC4413-1/LTC4413-2 (VDD) then diverts to draw current from the VOUTA pin, only if VOUTA is larger than VINB (or VOUTB). The system is now in the reverse turn-off mode. Power to the load is being delivered from an alternate supply, and only a small current (ILEAK) is drawn from or sourced to VINA to sense the potential at VINA. When the selected channel of the LTC4413-1/LTC4413-2 is in reverse turn-off mode or both channels are disabled, the STAT pin sinks 11A of current (ISON) if connected. Channel selection is accomplished using the two ENB pins, ENBA and ENBB. When the ENBA input is asserted (high), PA has its gate voltage pulled to VDD, turning off PA. A 3.5A pull-down current on the ENB pins ensures a low level at these inputs if left floating.
0 0 VFWD FORWARD VOLTAGE (V)
441312 TA01b
Figure 1. The LTC4413 vs the 1N5817
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LTC4413-1/LTC4413-2 OPERATION
Overcurrent and Short-Circuit Protection During an overcurrent condition, the output voltage droops as the load current exceeds the amount of current that the LTC4413-1/LTC4413-2 can supply. At the time when an overcurrent condition is first detected, the LTC4413-1/ LTC4413-2 take some time to detect this condition before reducing the current to IOC. For short durations after the output is shorted, until TOC, the current may exceed IOC. The magnitude of this peak short-circuit current can be large depending on the load current immediately before the short circuit occurs. During overcurrent operation, the power consumption of the LTC4413-1/LTC4413-2 is large, and is likely to cause an overtemperature condition as the internal die temperature exceeds the thermal shutdown temperature. Overtemperature Protection The overtemperature condition is detected when the internal die temperature increases beyond 150C. An overtemperature condition will cause the gate amplifiers (A and B) as well as the two P-channel MOSFETs (PA and PB) to shut off. When the internal die temperature cools to below 140C, the amplifiers turn on and the LTC4413-1/LTC4413-2 reverts to normal operation. Note that prolonged operation under overtemperature conditions degrades reliability. Overvoltage Protection (LTC4413-2 Only) An overvoltage condition is detected whenever the overvoltage input (OVI) pin is pulled above 6V. The condition persists until the OVI voltage falls below 5.6V. The overvoltage protection (OVP) output is low unless an overvoltage condition is detected. If an overvoltage condition is present, the OVP output is pulled up to the voltage applied to the OVI input. This output signal can be used to enable or disable an external PFET that is placed between the input that is the source of the excessive voltage and the input to the LTC4413-2, thus eliminating the potential damage that may occur to the LTC4413-2 if its input voltage exceeds the absolute maximum voltage of 6V. See the Applications Information section Dual Battery Load Sharing with Automatic Switchover to a Wall Adapter with Overvoltage Protection for more information on using the overvoltage protection function within the LTC4413-2. Channel Selection and Status Output Two active-high control pins independently turn off the two ideal diodes contained within the LTC4413-1/LTC4413-2, controlling the operation mode as described by Table 1. When the selected channel is reverse biased, or the LTC4413-1/LTC4413-2 is put into low power standby, the status signal indicates this condition with a low voltage.
Table 1: Mode Control
ENB1 Low Low High High ENB2 Low High Low High STATE Diode'OR NB: The Two Outputs are not Connected Internal to the Device Diode A = ENABLED, Diode B = DISABLED Diode A = DISABLED, Diode B = ENABLED All Off (Low Power Standby)
The function of the STAT pin depends on the mode that has been selected. Table 2 describes the STAT pin output current, as a function of the mode selected as well as the conduction state of the two diodes.
Table 2: STAT Output Pin Function
ENB1 Low ENB2 Low CONDITIONS Diode A Forward Bias, Diode B Forward Bias Diode A Forward Bias, Diode B Reverse Bias Diode A Reverse Bias, Diode B Forward Bias Diode A Reverse Bias, Diode B Reverse Bias Low High Diode A Forward Bias, Diode B Disabled Diode A Reverse Bias, Diode B Disabled High Low Diode A Disabled, Diode B Forward Bias Diode A Disabled, Diode B Reverse Bias High High Diode A Disabled, Diode B Disabled STAT ISNK = 0A ISNK = 0A ISNK = 11A ISNK = 11A ISNK = 0A ISNK = 11A ISNK = 0A ISNK = 11A ISNK = 11A
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LTC4413-1/LTC4413-2 APPLICATIONS INFORMATION
Introduction The LTC4413-1/LTC4413-2 are intended for power control applications that include low loss diode OR'ing, fully automatic switchover from a primary to an auxiliary source of power, microcontroller controlled switchover from a primary to an auxiliary source of power, load sharing between two or more batteries, charging of multiple batteries from a single charger and high side power switching. Dual Battery Load Sharing With Automatic Switchover to a Wall Adapter With Overvoltage Protection (LTC4413-2 Only) An application circuit for dual battery load sharing with automatic switchover of load from batteries to a wall adapter is shown in Figure 2. When the wall adapter is not present, whichever battery has the higher voltage provides the load current until it has discharged to the voltage of the other battery. The load is shared between the two batteries according to the capacity of each battery. The higher capacity battery provides proportionally higher current to the load. When a wall adapter input is applied, the output voltage rises as the body diode in MP2 conducts. When the output voltage is larger than the battery voltages, the LTC4413 turns off and very little load current is drawn from the batteries. At this time, the STAT pin pulls down
MP1 MP2 IRLML6402 IRLML6402 WALL ADAPTER INPUT JACK
the gate voltage of MP2, causing it to conduct. This status signal can be used to provide information as to whether the wall adapter (or BATB) is supplying the load current. If the wall adapter voltage exceeds the OVI trip threshold (VOVIH) then the wall adapter is disconnected via the external PFET, MP1. The OVI voltage can be monitored (through a voltage divider if necessary) to determine if an overvoltage condition is present. Capacitor C2 is required to dynamically pull up on the gate of PFET MP1 if a fast edge occurs at the wall adapter input during a hot plug. In the event that capacitor C2 (or the gate-to-source of MP1) is precharged below the OVI rising threshold. When a high voltage spike occurs, the OVP output cannot guarantee turning off MP1 before the load voltage exceeds the absolute maximum voltage for the LTC4413-2. This may occur in the event that the wall adapter suddenly steps from 5.5V to a much higher value. In this case, a zener diode is recommended to keep the output voltage to a safe level. Automatic PowerPath Control Figure 3 illustrates an application circuit for microcontroller monitoring and control of two power sources. The microcontroller's analog inputs (perhaps with the aid of a resistor voltage divider) monitor each supply input and the LTC4413-1 status, and then commands the LTC4413-1 through the two ENBA/ENBB control inputs.
RSTAT 470k
C1 0.10F R1 1
C2 10nF
MICROCONTROLLER OPTIONAL 6.2V DFLZ6V2-7 TO LOAD
BATA
1 INA 2
OUTA 10
+
PRIMARY POWER SOURCE
1 INA CA 10F RA 1 2 3 4 IDEAL
OUTA 10 9 STAT
LOAD
BATB
IDEAL 9 STAT ENBA LTC4413-2 3 8 GND OVI 4 7 ENBB OVP OUTB 6 5 INB IDEAL COUT 4.7F
10nF
RSTAT 470k
441312 F02
STAT ENBA LTC4413-1 GND
STAT OVP
+
C1: C1206C106K8PAC C2: C0403C103K8PAC COUT: C1206C475K8PAC
AUXILIARY POWER SOURCE
ENBB 5 INB CB 10F RB 1 IDEAL
OUTB 6 C1 4.7F
441312 F03
Figure 2
Figure 3
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11
LTC4413-1/LTC4413-2 APPLICATIONS INFORMATION
Automatic Switchover from a Battery to an Auxiliary Supply, or a Wall Adapter with Overvoltage Protection Figure 4 illustrates an application circuit where the LTC44132 is used to automatically switch over between a battery, an auxiliary power supply and a wall adapter. When the battery is supplying load current, OVP is at GND and STAT is high. If a higher supply is applied to AUX, the BAT will be disconnected from the load and the load is powered from AUX. When a wall adapter is applied, the body diode of MP2 forward biases. When the load voltage exceeds the AUX (or BAT) voltage, the LTC4413-2 senses this higher voltage and disconnects AUX (or BAT) from the load. At the same time it pulls the STAT voltage to GND, thereby turning on MP2. The load current is now supplied from the wall adapter. If the wall adapter voltage exceeds the OVI rising threshold, the OVP voltage rises and turns off MP1, disconnecting the wall adapter from the load. The output voltage collapses down to the AUX (or BAT) voltage and
MP1 MP2 IRLML6402 IRLML6402 WALL ADAPTER INPUT JACK
the LTC4413-2 reconnects the load to AUX (or BAT). Capacitor C2 is required to dynamically pull up on the gate of MP1 if a fast edge occurs at the wall adapter input during a hot plug. If the wall adapter voltage is precharged when an overvoltage spike occurs, the OVP voltage may not discharge capacitor C2 in time to protect the output. In this event, a zener diode is recommended to protect the output node until MP1 is turned off. Multiple Battery Charging Figure 5 illustrates an application circuit for automatic dual battery charging from a single charger. Whichever battery has the lower voltage will receive the 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 float voltage minus the forward regulation voltage of 15mV. This concept can apply to more than two batteries. The STAT pin provides information as to when the battery at OUTA is being charged. For intelligent control, the ENBA/ENBB input pins can be used with a microcontroller as shown in Figure 3. Automatic Switchover from a Battery to a Wall
C1 0.10F R1 1
C2 10nF
1 INA
OUTA 10 IDEAL 8
OPTIONAL 6.2V DFLZ6V2-7 TO LOAD
+
BAT 3 4 GND
OVI LTC4413-2 7 ENBB OVP 9 STAT OUTB 6 IDEAL ENBA COUT 4.7F
441312 F04
BATTERY CHARGER INPUT
1 INA 2 IDEAL
OUTA 10 VCC 470k STAT IS HIGH WHEN BAT1 IS CHARGING
+
LOAD BAT1
OVP 10nF
RSTAT 560k STAT
AUX 470k 470k
5 INB 2
ENBA LTC4413-1 3 9 STAT GND 4 ENBB OUTB 6 5 INB IDEAL
C1: C1206C106K8PAC C2: C0403C103K8PAC COUT: C1206C475K8PAC
+
BAT2
441312 F05
LOAD
Figure 4
Figure 5
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12
LTC4413-1/LTC4413-2 APPLICATIONS INFORMATION
Adapter and Charger with Overvoltage Protection Figure 6 illustrates the LTC4413-2 performing the function of automatically switching a load over from a battery to a wall adapter while controlling an LTC4059 battery charger. When no wall adapter is present, the LTC4413-2 connects the load at OUTA from the Li-Ion battery at INA. In this condition, the STAT voltage is high, thereby disabling the battery charger. If a wall adapter of a higher voltage than the battery is connected to MP1 (but below the OVI threshold), the load voltage rises as the second ideal diode conducts. As soon as the OUTA voltage exceeds the INA voltage, the BAT is disconnected from the load and the STAT voltage falls, turning on the LTC4059 battery charger and beginning a charge cycle. If a high voltage wall adapter is inadvertently attached above the OVI rising threshold, the OVP pin voltage rises, disconnecting both the LTC4413-2 and the LTC4059 from potentially hazardous voltages. When this occurs, the load voltage collapses until it is below the BAT voltage causing the STAT voltage to rise, disabling the battery charger. At the same time, the LTC4413-2 automatically reconnects the battery to the load. One major benefit of this circuit is that when a wall adapter is present, the user may remove the battery and replace it without disrupting the load. Capacitor C2 is required to dynamically pull up on the gate of MP1 if a fast edge occurs at the wall adapter input during a hot plug. If the wall adapter voltage is precharged when an overvoltage spike occurs, the OVP voltage may not discharge capacitor C2 in time to protect the output. In this event, a zener diode is recommended to protect the output node until MP1 is turned off. Soft-Start Overvoltage Protection
STAT STAT ENB BAT 1 INA 9 RSTAT 560k TO LOAD
OUTA 10
LTC4059 VCC PROG MP1 IRLML6402 Li/CC GND WALL ADAPTER INPUT JACK C1 10F Li-Ion 100k
+
IDEAL ENBA LTC4413-2 4 ENBB 3 GND OUTB 6 5 INB 2 IDEAL OVP COUT 4.7F
1F
D1 OPTIONAL DFLZ6V2-7
C2 10nF OVI
441312 F06
Figure 6
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13
LTC4413-1/LTC4413-2 APPLICATIONS INFORMATION
In the event that a low power external PFET is used for the external overvoltage protection device, care must be taken to limit the power dissipation in the external PFET. The operation of this circuit is identical to the "Automatic Switchover from a Battery to a Wall Adapter" application shown on the first page of this data sheet. Here, however, the ideal diode from INA to INB is disabled by pulling up on ENBA whenever an overvoltage condition is detected. This channel is turned-off using a resistor connected to OVP along with a 5.6V zener diode, ensuring the absolute maximum voltage at ENBA is not exceeded during an overvoltage event. When the overvoltage condition ends, the OVP voltage drops slowly, depending on the gate charge of the external PFET. This causes the external PFET to linger in a high RDS(ON) region where it can dissipate a significant amount of heat depending on the load current. To avoid dissipating heat in the external PFET, this application delays turning on the ideal diode from INA to OUTA, until the gate voltage of the external PFET drops below VENBIL, where the external PFET should safely be out of the high RDS(ON) region. This soft-start scheme can be used on either channel of the LTC4413-2.
FDR8508 WALL ADAPTER INPUT C2 10nF 0.1F 1 RENBA 560k D2 5.6V STAT ENBA LTC4413-2 OVI GND ENBB INB IDEAL
441312 F07
INA C1 10F D1 OPTIONAL IDEAL
OUTA
VCC RSTAT 470k STAT
BAT
OVP OUTB COUT 4.7F
OVP TO LOAD
+
C1: C0805C106K8PAC C2: C0403C103K8PAC COUT: C1206C475K8PAC
STAT IS HIGH WHEN WALL ADAPTER IS SUPPLYING LOAD CURRENT OVP IS HIGH WHEN WALL ADAPTER VOLTAGE > 6V
Figure 7
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14
LTC4413-1/LTC4413-2 PACKAGE DESCRIPTION
DD Package 10-Lead Plastic DFN (3mm x 3mm)
(Reference LTC DWG # 05-08-1699)
0.675 0.05
3.50 0.05 1.65 0.05 2.15 0.05 (2 SIDES) PACKAGE OUTLINE 0.25 0.05 0.50 BSC 2.38 0.05 (2 SIDES) RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS R = 0.115 TYP 6 0.38 0.10 10
3.00 0.10 (4 SIDES) PIN 1 TOP MARK (SEE NOTE 6)
1.65 0.10 (2 SIDES)
(DD) DFN 1103
5 0.200 REF 0.75 0.05 2.38 0.10 (2 SIDES)
1 0.25 0.05 0.50 BSC
0.00 - 0.05
BOTTOM VIEW--EXPOSED PAD NOTE: 1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WEED-2). CHECK THE LTC WEBSITE DATA SHEET FOR CURRENT STATUS OF VARIATION ASSIGNMENT 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
441312fb
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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
15
LTC4413-1/LTC4413-2 TYPICAL APPLICATION
Automatic Switchover from a Battery to a Wall Adapter with Soft-Start Overvoltage Protection
FDR8508 WALL ADAPTER INPUT C2 10nF 0.1F 1 RENBA 560k D2 5.6V ENBA STAT LTC4413-2 OVI GND ENBB INB IDEAL
441312 F07
INA C1 10F D1 OPTIONAL IDEAL
OUTA
VCC RSTAT 470k STAT
BAT
OVP OUTB COUT 4.7F
OVP TO LOAD
+
C1: C0805C106K8PAC C2: C0403C103K8PAC COUT: C1206C475K8PAC
STAT IS HIGH WHEN WALL ADAPTER IS SUPPLYING LOAD CURRENT OVP IS HIGH WHEN WALL ADAPTER VOLTAGE > 6V
RELATED PARTS
PART NUMBER LTC1558/LTC1559 LTC1998 LTC4054 LTC4350 LTC4411 DESCRIPTION Backup Battery Controller with Programmable Output 2.5A, 1% Accurate Programmable Battery Detector 800mA Standalone Linear Li-Ion Battery Charger with Thermal Regulation in ThinSOT Hot Swappable Load Share Controller 2.6A Low Loss Ideal Diode in ThinSOT COMMENTS Adjustable Backup Voltage from 1.2V NiCd Button Cell, Includes Boost Converter Adjustable Trip Voltage/Hysteresis, ThinSOTTM No External MOSFET, Sense Resistor or Blocking Diode Required, Charge Current Monitor for Gas Guaging, C/10 Charge Termination Allows N + 1 Redundant Supply, Equally Loads Multiple Power Supplies Connected in Parallel No External MOSFET, Automatic Switching Between DC sources, Simplified Load Sharing More Efficient than Diode OR'ing, Automatic Switching Between DC Sources, Simplified Load Sharing, 3V VIN 28V, 3V VIN 36V (HV) Drives Large QG PFETs, Very Low Loss Replacement for Power Supply O'Ring Diodes, 3.5V to 36V AC/DC Adapter Voltage Range, 8-Lead MSOP Package
LTC4412/LTC4412HV PowerPath Controller in ThinSOT LTC4413 LTC4414
Dual 2.6A, 2.5V to 5.5V, Ideal Diodes in 3mm x 3mm DFN Lower Quiescent Current with Slower Response Time 36V, Low Loss PowerPath Controller for Large PFETs
ThinSOT is a trademark of Linear Technology Corporation.
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16 Linear Technology Corporation
(408) 432-1900 FAX: (408) 434-0507
LT 0907 REV B * PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
www.linear.com
(c) LINEAR TECHNOLOGY CORPORATION 2006

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