LTC4413-1/LTC4413-2 Dual 2.6A, 2.5V to 5.5V Fast Ideal Diodes in 3mm × 3mm DFN DESCRIPTION FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 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 (140mΩ 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 × 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 The LTC®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 100mΩ 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 80μA 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 1μA 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 11μA open drain. The LTC4413-1/LTC4413-2 are housed in a 10-lead 3mm × 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. TYPICAL APPLICATION Power Loss vs Load Automatic Switchover from a Battery to a Wall Adapter FDR8508 600 VCC OUTA INA 10μF 0.1μF 1Ω BAT + 470k IDEAL ENBA STAT LTC4413-2 GND OVI ENBB INB STAT OVP OVP OUTB TO LOAD 4.7μF IDEAL 441312 TA01a STAT IS HIGH WHEN WALL ADAPTER IS SUPPLYING LOAD CURRENT OVP IS HIGH WHEN WALL ADAPTER VOLTAGE > 6V POWER LOSS (mW) WALL ADAPTER INPUT 700 500 LTC4413-1 400 300 1N5817 200 100 0 0 500 1000 1500 2000 LOAD (mA) 2500 3000 441312 TA01b 441312fb 1 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.................. –40°C to 85°C Storage Temperature Range................... –65°C to 125°C Continuous Power Dissipation ..........................1500mW (Derate 25mW/°C Above 70°C) PIN CONFIGURATION TOP VIEW TOP VIEW INA 1 10 OUTA INA 1 ENBA 2 9 STAT ENBA 2 GND 3 8 NC GND 3 ENBB 4 7 NC ENBB 4 7 OVP INB 5 6 OUTB INB 5 6 OUTB 11 DD PACKAGE 10-LEAD (3mm × 3mm) PLASTIC DFN TJMAX = 125°C, θJA = 43°C/W EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB 10 OUTA 9 STAT 11 8 OVI DD PACKAGE 10-LEAD (3mm × 3mm) PLASTIC DFN TJMAX = 125°C, θJA = 43°C/W EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC4413EDD1#PBF LTC4413EDD1#TRPBF LCPP 10-Lead (3mm × 3mm) Plastic DFN –40°C to 85°C LTC4413EDD2#PBF LTC4413EDD2#TRPBF LCPQ 10-Lead (3mm × 3mm) Plastic DFN –40°C to 85°C LEAD BASED FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE LTC4413EDD1 LTC4413EDD1#TR LCPP 10-Lead (3mm × 3mm) Plastic DFN –40°C to 85°C LTC4413EDD2 LTC4413EDD2#TR LCPQ 10-Lead (3mm × 3mm) Plastic DFN –40°C to 85°C 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 The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. (Notes 2, 6) SYMBOL PARAMETER CONDITIONS MIN VIN, VOUT Operating Supply Range for Channel A or B VIN and/or VOUT Must be in This Range for Proper Operation ● UVLO UVLO Turn-On Rising Threshold Max (VINA, VINB, VOUTA, VOUTB) ● UVLO Turn-Off Falling Threshold Max (VINA, VINB, VOUTA, VOUTB) ● IQF Quiescent Current in Forward Regulation, Measured via GND VINA = 3.6V, IINA = 100mA, VINB = 0V, IINB = 0mA (Note 3) ● IQRIN Current Drawn from or Sourced into IN when VOUT is greater than VIN VIN = 3.6V, VOUT = 5.5V (Note 6) ● IQRGND Quiescent Current While in Reverse Turn-Off, Measured via GND VINA = VINB = 0V, VOUTB = VOUTA = 5.5V, VSTAT = 0V TYP 2.5 MAX 5.5 V 2.45 V 40 58 μA 2.5 4.5 μA 28 36 μA 1.7 –1 UNITS V 441312fb 2 LTC4413-1/LTC4413-2 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. (Notes 2, 6) SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS 3.5 6.5 μA 28 38 μA 10 mV 18 24 mV IQROUTB Quiescent Current While in Reverse Turn-Off. Current Drawn from VOUTA when OUTB Supplies Chip Power VINA = VINB = 0V, VOUTA = 3.6V, VOUTB = 5.5V ● IQOFF Quiescent Current with Both ENBA and ENBB High VINA = VINB = 3.6V, VENBA = VENBB = 1V ● VRTO Reverse Turn-Off Voltage (VOUT – VIN) VIN = 3.6V ● VFWD Forward Voltage Drop (VIN – VOUT) at IOUT = –1mA VIN = 3.6V ● RFWD On-Resistance, RFWD Regulation (Measured as ΔV/ΔI) VIN = 3.6V, IOUT = –100mA to –500mA (Note 5) 100 140 mΩ RON On-Resistance, RON Regulation (Measured as V/I at IIN = 1A) VIN = 3.6V, IIN = 1A (Note 5) 140 200 mΩ tON PowerPath Turn-On Time VIN = 3.6V, from ENB Falling to IOUT Ramp Starting 11 μs tOFF PowerPath Turn-Off Time VIN = 3.6V, from ENB Rising with IIN = 100mA Falling to 0mA 2 μs –5 Short-Circuit Response IOC Current Limit VINA OR B = 3.6V (Note 5) 1.8 A IQOC Quiescent Current While in Overcurrent Operation VINA OR B = 3.6V, IOUT = 1.8A (Note 5) ISOFF STAT Off Current Shut Down ● ISON STAT Sink Current VIN > VOUT, VCTL < VIL, TJ < 135°C, IOUT < IMAX ● tS(ON) STAT Pin Current Turn-On Time VIN = 3.6V, from ENB Falling 1.8 μs tS(OFF) STAT Pin Current Turn-Off Time VIN = 3.6V, from ENB Rising 0.8 μs VENBIH ENB Inputs Rising Threshold Voltage VENB Rising ● VENBIL ENB Inputs Falling Threshold Voltage VENB Falling ● VENBHYST ENB Input Hysteresis VENBHYST = (VENBIH – VENBIL) 100 130 μA –1 0 1 μA 7 11 13 μA STAT Output ENB Inputs IENB ENB Inputs Pull-Down Current VOUT < VIN = 3.6V, VENB < VIL ● 540 400 2 600 mV 460 mV 90 mV 3 4 μA 5.9 6.2 V OVI Input (LTC4413-2 Only) VOVIH OVI Input Rising Threshold Voltage VOVI Rising VOVIL OVI Input Falling Threshold Voltage VOVI Falling VOVID OVI-OVP Voltage Drop IOVI OVI Bias Current 5.6 V VOVI = 8V, No Load at OVP 100 mV VOVI = 8V 80 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: The LTC4413-1/LTC4413-2 are guaranteed to meet performance specifications from 0°C to 85°C. Specifications over the –40°C to 85°C 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. 5.4 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. 441312fb 3 LTC4413-1/LTC4413-2 TYPICAL PERFORMANCE CHARACTERISTICS IQF vs ILOAD (Log) IQF vs ILOAD (Linear) 120 IQF vs Temperature 120 120 120°C 120°C 100 80°C 40°C 40°C 0°C –40°C 60 80 –40°C 60 500mA 60 40 40 40 20 20 20 0 1 10 100 LOAD (mA) 1000 0 10000 0 2500 1000 1500 2000 LOAD (mA) 500 441312 G01 IQF vs VIN 2.20 3000 2.15 2500 IOC (mA) 2000 IQF = 100mA 40 40 80 TEMPERATURE (°C) 30 120 UVLO Thresholds vs Temperature 3500 60 50 0 441312 G03 UVLO THRESHOLDS (V) IQF = 1A 70 1mA 0 –40 3000 IOC vs Temperature 80 100mA 441312 G02 90 IQF (μA) 1A 0°C 80 IQF (μA) IQF (μA) 80 100 IQF (μA) 80°C 100 1500 1000 RISING 2.10 2.05 2.00 FALLING 1.95 20 500 10 2 2.5 3 3.5 4 4.5 5 5.5 0 –40 6 0 VIN (V) 40 UVLO Hystersis vs Temperature ENB Hysteresis vs Temperature 120 100 500 ENBIH/ENBIL (mV) 100 50 ENBIH ENBIL 400 300 200 100 120 441312 G07 0 –40 80 60 40 20 100 20 40 60 80 TEMPERATURE (°C) 120 80 441312 G06 ENB Thresholds vs Temperature 200 150 40 TEMPERATURE (°C) 600 0 0 441312 G05 250 UVLO HYSTERESIS (mV) 1.85 –40 TEMPERATURE (°C) 441312 G04 0 –40 –20 120 80 ENB HYSETERSIS (mV) 0 1.90 0 40 80 TEMPERATURE (°C) 120 441312 G08 0 –40 –20 0 20 40 60 80 TEMPERATURE (°C) 100 120 441312 G09 441312fb 4 LTC4413-1/LTC4413-2 TYPICAL PERFORMANCE CHARACTERISTICS VFWD and RFWD vs ILOAD (Linear) 500 120°C 80°C 40°C 0°C –40°C 78 400 76 RFWD (mΩ) 68 500 200 VFWD 400 300 150 200 100 66 RFWD 64 100 50 300 120°C 80°C 40°C 0°C –40°C RFWD 250 200 VFWD 300 150 200 100 100 50 VFWD (mV) 70 600 VFWD (mV) RFWD 500mA (mΩ) 74 72 RFWD and VFWD vs ILOAD (Log) 250 RFWD (mΩ) RFWD vs VIN and ILOAD = 500mA 80 62 0 60 2.5 3.5 3 4 4.5 VIN (V) 5 5.5 6 0 500 1000 1500 2000 LOAD (mA) 2500 VFWD vs ILOAD (Log) 100 LOAD (mA) 0 10000 1000 441312 G12 ILEAK vs Temperature at VREVERSE = 5.5V 1 120 100 0.1 100mA 80 RFWD (mΩ) VFWD (mV) 10 RFWD vs Temperature 120°C 80°C 40°C 0°C –40°C 200 1 441312 G11 441312 G10 250 0 0 3000 150 100 500mA ILEAK (μA) 2 1A 60 5.5V 0.01 3.6V 0.001 40 50 0.0001 20 0 10 1 100 LOAD (mA) 1000 10000 0 –40 0 40 80 TEMPERATURE (°C) 441312 G13 120 0 20 40 60 80 TEMPERATURE (°C) 100 120 441312 G15 441312 G14 Response to 800mA Load Step in <16μs ILEAK vs VREVERSE 0.00001 –40 –20 ENB Turn-On, 30μs to Turn On with 180mA Load 100 120°C 80°C 40°C 0°C –40°C 10 ILEAK (μA) 1 CH1 = IN 100mV/DIV CH1 IN 1V/DIV CH2 OUT 100mV/DIV CH3 ENB 1V/DIV CH2 OUT 1V/DIV 0.1 CH4 IOUT 200mV/DIV 0.01 CH4 IOUT 200mV/DIV 0.001 4μs/DIV 0.0001 441312 G17 10μs/DIV 441312 G18 0.00001 0 1 2 3 4 VREVERSE (V) 5 6 441312 G16 441312fb 5 LTC4413-1/LTC4413-2 TYPICAL PERFORMANCE CHARACTERISTICS ENB Turn-Off, 2μs to Disconnect IN from 180mA Load Efficiency vs Load Current Power Loss vs Load Current 100 1000 120°C 80°C 40°C 0°C –40°C 99 CH1 IN 1V/DIV CH2 OUT 1V/DIV CH3 ENB 1V/DIV CH4 IIN 100mV/DIV 100 97 96 95 94 93 120°C 80°C 40°C 0°C –40°C 92 441312 G19 4μs/DIV POWER LOSS (mW) EFFICIENCY (%) 98 91 90 1 10 10 1 0 100 LOAD (mA) 1000 10000 10 1 100 LOAD (mA) 1000 441312 G20 OVI Current vs Voltage (LTC4413-2 Only) 6.4 400 140 6.2 350 120 5.8 OVP FALLING 5.6 5.4 5.2 300 200 0 40 20 0 0 TEMPERATURE (°C) 40 80 0 120 160 5 140 IQ OVI = 13V VOHOVP = 13V OVI-OVP (mV) IQ OVI (μA) OVP (V) 120 120 4 100 IQ OVI = 6.5V 80 60 4 8 6 OVI (V) 10 12 60 20 20 0 –40 0 40 80 120 441312 G26 VOHOVP = 6.5V 80 40 TEMPERATURE (°C) 441312 G25 100 40 1 0 12 160 140 2 10 OVI-OVP vs Temperature (LTC4413-2 Only) 180 3 8 6 VOVI (V) 441312 G24 IQ OVI vs Temperature (LTC4413-2 Only) TA = 25°C 2 4 441312 G23 OVI-OVP Voltage Drop vs OVI Voltage (LTC4413-2 Only) 0 2 TEMPERATURE (°C) 441312 G22 6 60 40 100 0 –40 120 80 80 150 50 5.0 –40 TA = 25°C 100 250 IOVI (μA) OVP RISING 6.0 OVP HYSTERESIS (mV) OVPIH/OVPIL (V) 441312 G21 Overvoltage Hysteresis vs Temperature (LTC4413-2 Only) Overvoltage Thresholds vs Temperature (LTC4413-2 Only) 10000 0 –40 –20 0 20 40 60 80 TEMPERATURE (°C) 100 120 441312 G27 441312fb 6 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 1μF. (Series 1Ω 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/μs. 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 (3.5μA) pull-down internal to LTC4413-1/LTC4413-2 is included. 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. GND (Pin 3): Power Ground for the IC. STAT (Pin 9): Status Condition Indicator. Weak (11μA) 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. 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 (3.5μA) pull-down internal to LTC4413-1/LTC4413-2 is included. OUTA (Pin 10): Primary Ideal Diode Cathode and Output of the LTC4413-1/LTC4413-2. Bypass OUTA with a high (1mΩ min) ESR ceramic capacitor of at least 4.7μF. This pin must be left floating when not in use. Limit slew rate on this pin to less than 2.5V/μs. 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 1μF. (Series 1Ω 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/μs. 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. OUTB (Pin 6): Secondary Ideal Diode Cathode and Output of the LTC4413-1/LTC4413-2. Bypass OUTB with a high (1mΩ min) ESR ceramic capacitor of at least 4.7μF. This pin must be left floating when not in use. Limit slew rate on this pin to less than 2.5V/μs. 441312fb 7 LTC4413-1/LTC4413-2 BLOCK DIAGRAM OUTA INA OVER CURRENT 0.5V 2 ENBA – + + – 1 –+ VOFF PA – + VGATEA AENA ENA A UVLO ENA ENB OUTA (MAX) OUTB (MAX) AENA OVER TEMP BENA OVER TEMP STAT STB GND OUTB INB OVER CURRENT 0.5V 4 11μA ENBB – + + – 5 9 + – 3μA 3 10 –+ VOFF ENB 6 PB LTC4413-2 ONLY OVERVOLTAGE PROTECTION OVI – + VGATEB BENA B + – 6V + – OVP 8 7 3μA 441312 BD 441312fb 8 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 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 11μA 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 3.5μA pull-down current on the ENB pins ensures a low level at these inputs if left floating. LTC4413-1 LTC4413-2 CURRENT (A) SLOPE: 1/RON IFWD 1N5817 SLOPE: 1/RFWD 0 0 VFWD FORWARD VOLTAGE (V) 441312 TA01b Figure 1. The LTC4413 vs the 1N5817 441312fb 9 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 150°C. 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 140°C, 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 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 ENB2 STATE Low Low Diode’OR NB: The Two Outputs are not Connected Internal to the Device Low High Diode A = ENABLED, Diode B = DISABLED High Low Diode A = DISABLED, Diode B = ENABLED High High 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 ENB2 CONDITIONS STAT Low Low Diode A Forward Bias, Diode B Forward Bias ISNK = 0μA Diode A Forward Bias, Diode B Reverse Bias ISNK = 0μA Diode A Reverse Bias, Diode B Forward Bias ISNK = 11μA Diode A Reverse Bias, Diode B Reverse Bias ISNK = 11μA Diode A Forward Bias, Diode B Disabled ISNK = 0μA Diode A Reverse Bias, Diode B Disabled ISNK = 11μA Diode A Disabled, Diode B Forward Bias ISNK = 0μA Diode A Disabled, Diode B Reverse Bias ISNK = 11μA Diode A Disabled, Diode B Disabled ISNK = 11μA 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 Low High High High Low High 441312fb 10 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 BATA + C1 0.10μF R1 1Ω 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 C2 10nF MICROCONTROLLER OPTIONAL 6.2V DFLZ6V2-7 OUTA 10 1 INA 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. TO LOAD IDEAL 9 STAT ENBA LTC4413-2 3 8 GND OVI 4 7 ENBB OVP OUTB 6 5 INB PRIMARY POWER SOURCE 2 BATB + 10nF 441312 F02 COUT 4.7μF IDEAL Figure 2 RSTAT 470k 1 INA CA 10μF RA 1Ω STAT OVP C1: C1206C106K8PAC C2: C0403C103K8PAC COUT: C1206C475K8PAC 2 3 OUTA 10 IDEAL STAT ENBA LTC4413-1 GND 9 LOAD STAT 4 AUXILIARY POWER SOURCE ENBB 5 INB CB 10μF OUTB 6 C1 4.7μF IDEAL 441312 F03 RB 1Ω Figure 3 441312fb 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 C1 0.10μF R1 1Ω OUTA 10 1 INA + 3 BAT 4 GND IDEAL 470k 470k 2 TO LOAD 8 OVP 10nF OUTB 6 IDEAL COUT 4.7μF ENBA 441312 F04 Figure 4 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 OPTIONAL 6.2V DFLZ6V2-7 OVI LTC4413-2 7 ENBB OVP 9 STAT 5 INB AUX C2 10nF the LTC4413-2 reconnects the load to AUX (or BAT). RSTAT 560k STAT C1: C1206C106K8PAC C2: C0403C103K8PAC COUT: C1206C475K8PAC BATTERY CHARGER INPUT OUTA 10 1 INA 2 LOAD BAT1 ENBA LTC4413-1 3 9 STAT GND 4 ENBB OUTB 6 5 INB IDEAL + VCC IDEAL 470k STAT IS HIGH WHEN BAT1 IS CHARGING LOAD + BAT2 441312 F05 Figure 5 441312fb 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 1 INA BAT LTC4059 + VCC PROG MP1 IRLML6402 Li-Ion 100k Li/CC GND WALL ADAPTER INPUT JACK 1μF C1 10μF 9 OUTA 10 RSTAT 560k TO LOAD IDEAL ENBA LTC4413-2 4 ENBB 3 GND OUTB 6 5 INB 2 D1 OPTIONAL DFLZ6V2-7 COUT 4.7μF IDEAL OVP C2 10nF OVI 441312 F06 Figure 6 441312fb 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 INA C1 10μF C2 10nF 0.1μF D1 OPTIONAL OUTA IDEAL VCC RSTAT 470k RENBA 560k D2 5.6V 1Ω BAT STAT ENBA LTC4413-2 OVI GND STAT OVP OUTB OVP ENBB INB + COUT 4.7μF IDEAL TO LOAD 441312 F07 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 441312fb 14 LTC4413-1/LTC4413-2 PACKAGE DESCRIPTION DD Package 10-Lead Plastic DFN (3mm × 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 3.00 ±0.10 (4 SIDES) R = 0.115 TYP 6 0.38 ± 0.10 10 1.65 ± 0.10 (2 SIDES) PIN 1 TOP MARK (SEE NOTE 6) (DD) DFN 1103 5 0.200 REF 1 0.25 ± 0.05 0.50 BSC 0.75 ±0.05 0.00 – 0.05 2.38 ±0.10 (2 SIDES) 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 INA C1 10μF C2 10nF OUTA D1 OPTIONAL IDEAL VCC RSTAT 470k RENBA 560k 0.1μF D2 5.6V 1Ω ENBA STAT LTC4413-2 OVI GND STAT OVP OUTB OVP ENBB INB BAT + COUT 4.7μF IDEAL TO LOAD 441312 F07 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 DESCRIPTION COMMENTS LTC1558/LTC1559 Backup Battery Controller with Programmable Output Adjustable Backup Voltage from 1.2V NiCd Button Cell, Includes Boost Converter LTC1998 2.5μA, 1% Accurate Programmable Battery Detector Adjustable Trip Voltage/Hysteresis, ThinSOTTM LTC4054 800mA Standalone Linear Li-Ion Battery Charger with Thermal Regulation in ThinSOT No External MOSFET, Sense Resistor or Blocking Diode Required, Charge Current Monitor for Gas Guaging, C/10 Charge Termination LTC4350 Hot Swappable Load Share Controller Allows N + 1 Redundant Supply, Equally Loads Multiple Power Supplies Connected in Parallel LTC4411 2.6A Low Loss Ideal Diode in ThinSOT No External MOSFET, Automatic Switching Between DC sources, Simplified Load Sharing LTC4412/LTC4412HV PowerPath Controller in ThinSOT More Efficient than Diode OR’ing, Automatic Switching Between DC Sources, Simplified Load Sharing, 3V ≤ VIN ≤ 28V, 3V ≤ VIN ≤ 36V (HV) LTC4413 Dual 2.6A, 2.5V to 5.5V, Ideal Diodes in 3mm × 3mm DFN Lower Quiescent Current with Slower Response Time LTC4414 36V, Low Loss PowerPath Controller for Large PFETs 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 ThinSOT is a trademark of Linear Technology Corporation. 441312fb 16 Linear Technology Corporation LT 0907 REV B • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com © LINEAR TECHNOLOGY CORPORATION 2006