LTC4411ES5#TRMPBF

LTC4411 2.6A Low Loss Ideal Diode in ThinSOTTM U DESCRIPTIO FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Low Loss Replacement for PowerPathTM OR’ing Diodes Small Regulated Forward Voltage (28mV) 2.6A Maximum Forward Current Low Forward ON Resistance (140mΩ Max) Low Reverse Leakage Current ( VIH VIN = 3.6V VOUT = 3.7V VIN = 3.6V VOUT = 3.7V VIN = 0V, VOUT = 5.5V VIN = 3.6V VIN = 3.6V VIN = 3.6V, 100mA < ILOAD < 500mA VIN = 3.6V, ILOAD = 1000mA VIN Rising, 0°C < TA < 85°C VIN Rising VIN Falling MAX 5.5 UNITS V µA 40 ● ● 1.3 22 1.8 25 2.3 µA µA ● 14 17 23 µA ● –1 8 –4 1 28 14 140 245 2.5 2.6 µA mV mV mΩ mΩ V V ● ● ● ● VIN = 3.6V, VOUT > VIN + VRTO, VCTL > VTH + VHYST VIN = 3.6V, VOUT < VIN – VFWD, VCTL < VTH – VHYST VTH = (VIL + VIH)/2 VHYST = (VIH – VIL) VOUT < VIN = 3.6V, VCTL = 1.5V TYP 17 5 100 140 1.6 7 V 11 18 µA 1 µA 1.2 1.1 1.4 1.25 µs µs 530 mV mV µA –1 ● 390 ● 2 460 90 3.5 1.8 2.6 6 Short-Circuit Response IOC Current Limit VIN = 3.6V (Note 5) IQOC Quiescent Current While in Overcurrent Operation VIN = 3.6V, IOUT = 1.8A 575 A 1100 µA 4411fa 2 LTC4411 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. (Note 6) Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: The LTC4411E is guaranteed to meet performance specifications from 0°C to 70°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: TJ is calculated from the ambient temperature TA and power dissipation PD according to the following formula: TJ = TA + (PD • 150°C/W) The following table lists thermal resistance for several different board sizes and copper areas. All measurements were taken in still air on 3/32" FR-4 board with the device mounted on topside. Note 4: Quiescent current increases with load current, refer to plot of IQF vs ILOAD. Note 5: This IC 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 6: Current into a pin is positive and current out of a pin is negative. All voltages are referenced to GND. Measured Thermal Resistance (2-Layer Board*) COPPER AREA TOPSIDE BACKSIDE BOARD AREA THERMAL RESISTANCE JUNCTION-TO-AMBIENT 2500mm2 2500mm2 2500mm2 125°C/W 1000mm2 2500mm2 2500mm2 125°C/W 225mm2 2500mm2 2500mm2 130°C/W 100mm2 2500mm2 2500mm2 135°C/W 50mm2 2500mm2 2500mm2 150°C/W *Each layer uses one ounce copper U W TYPICAL PERFOR A CE CHARACTERISTICS 0.5 0.4 100 0.30 TA = –40°C TA = 0°C TA = 40°C TA = 80°C TA = 120°C 0.3 0.2 0.1 0 0.5 1.0 1.5 2.0 LOAD CURRENT (A) 2.5 3.0 4411 G01 0.20 0.15 0.10 0.05 0 10 TA = –40°C TA = 0°C TA = 40°C TA = 80°C TA = 120°C 0.25 RESISTANCE (Ω) TA = –40°C TA = 0°C TA = 40°C TA = 80°C TA = 120°C FORWARD VOLTAGE (V) QUIESCENT CURRENT (µA) 1000 RFWD and RON vs ILOAD at VIN = 3.6V VFWD vs ILOAD at VIN = 3.6V Typical IQF vs ILOAD at VIN = 3.6V 0 0.5 1.0 1.5 2.0 LOAD CURRENT (A) 2.5 3.0 4411 G02 0 0 0.5 1.0 1.5 LOAD CURRENT (A) 2.0 4411 G03 4411fa 3 LTC4411 U W TYPICAL PERFOR A CE CHARACTERISTICS RFWD vs Temperature at VIN = 3.6V RFWD vs VSUPPLY 0.150 TA = –40°C TA = 0°C TA = 40°C 0.100 0.075 IQROUT CURRENT (A) 0.15 RFWD (Ω) RFWD (Ω) 100µ TA = 80°C TA = 120°C 0.125 0.050 0.10 0.05 2.5 3.0 3.5 4.0 4.5 SUPPLY VOLTAGE (V) 5.0 5.5 0 –40 –20 0 20 40 60 80 TEMPERATURE (°C) 4411 G04 LEAKAGE CURRENT (A) 1µ 100n 0 5 1 2 3 4 REVERSE VOLTAGE (V) 5 6 4411 G06 CTL Turn-Off VCTRL 500mV/DIV VCTRL 500mV/DIV VSTAT 2V/DIV VSTAT 2V/DIV VOUT 2V/DIV IOUT 50mA/DIV 200µs/DIV 2 3 4 REVERSE VOLTAGE (V) TA = –40°C TA = 0°C TA = 40°C TA = 80°C TA = 120°C 100n 100 120 VOUT 2V/DIV IOUT 500mA/DIV 1 1µ CTL Turn-On TA = 60°C TA = 80°C TA = 100°C TA = 120°C 0 10µ 4411 G05 ILEAK vs VREVERSE, VIN = 0V 10µ 10n IQROUT vs VREVERSE at VIN = 0V 0.20 4411 G08 20µs/DIV 4411 G09 6 4411 G07 U U U PI FU CTIO S IN (Pin 1): Ideal Diode Anode and Positive Power Supply for LTC4411. When operating LTC4411 as a switch it must be bypassed with a low ESR ceramic capacitor of 1µF. X5R and X7R dielectrics are preferred for their superior voltage and temperature characteristics. GND (Pin 2): Power and Signal Ground for the IC. CTL (Pin 3): Controlled Shutdown Pin. Weak (3µA) PullDown. Pull this pin high to shut down the IC. Tie to GND to enable. Can be left floating when not in use. STAT (Pin 4): Status Condition Indicator. This pin indicates the conducting status of the LTC4411. If the part is forward biased (VIN > VOUT + VFWD) this pin will be Hi-Z. If the part is reverse biased (VOUT > VIN + VRTO), then this pin will pull down 10µA through an open-drain. When terminated to a high voltage through a 470k resistor, a high voltage indicates diode conducting. May be left floating or grounded when not in use. OUT (Pin 5): Ideal Diode Cathode and Output of the LTC4411. Bypass OUT with a nominal 1mΩ ESR capacitor of at least 4.7µF. The LTC4411 is stable with ESRs down to 0.2mΩ. However stability improves with higher ESRs. 4411fa 4 LTC4411 W BLOCK DIAGRA + IN – 1 5 OUT P1 –+ – VGATE + GND 2 OVERTEMP SHDB VREF CTL – + OFF 4 STAT A UVLO OUTMAX 3 3µA VB VB 10µA 4411 F02 Figure 2. Detailed Block Diagram U OPERATIO Operation begins when the power source at IN rises above the UVLO voltage of 2.4V (typ) and the CTL (control) pin is low. If only the voltage at the IN pin is present, the power source to LTC4411 (VDD) will be supplied from the IN pin. The amplifier (A) will deliver a voltage proportional to the difference between VIN and VOUT to the gate (VGATE) of the internal P-channel MOSFET (P1), driving this gate voltage below VIN. This will turn on P1. As P1 conducts, VOUT will be pulled up towards VIN. The LTC4411 will then control VGATE to maintain a low forward voltage drop. The system is now in forward regulation and the load at OUT will be powered from the supply at IN. As the load current varies, VGATE will be controlled to maintain a low forward voltage drop. If the load current exceeds P1’s ability to deliver the current, as VGATE approaches GND, the P1 will behave as a fixed resistor, with resistance RON, whereby the forward voltage will increase with increased load current. As ILOAD increases further (ILOAD > IMAX), the LTC4411 will regulate the load current as described below. During the forward regulation mode of operation the STAT pin will be an open circuit. 3.0 IOC LOAD CURRENT (A) The LTC4411 operation is described with the aid of Figure 3. Forward regulation for the LTC4411 has three operation modes depending on the magnitude of the load current. For small load currents, the LTC4411 will provide a constant voltage drop; this operating mode is referred to as “constant VON” regulation. As the current exceeds IFWD the voltage drop will increase linearly with the current with a slope of 1/RON; this operating mode is referred to as “constant RON” regulation. As the current increases further, exceeding IMAX, the forward voltage drop will increase rapidly; this operating mode is referred to as “constant ION” regulation. The characteristics for the following parameters: RFWD, RON, VFWD, IFWD, and IMAX are specified with the aid of Figure 3. TA = 40°C 2.5 IMAX 2.0 LTC4411 IFWD 1.5 SLOPE 1/RON 1.0 SLOPE 1/RFWD 0.5 0 0 VFWD SCHOTTKY DIODE 0.25 0.5 0.75 FORWARD VOLTAGE (V) 1.0 4411 F03 Figure 3. LTC4411 vs Schottky Diode Forward Conduction Characteristics 4411fa 5 LTC4411 U OPERATIO When the load current exceeds IMAX, an over current condition is detected and the LTC4411 will limit the output current. This will cause the output voltage to drop as the load current exceeds the amount of current that the LTC4411 can supply. This condition will increase the power consumption within the LTC4411. When an alternate power source is connected to the output, the LTC4411 will sense the increased voltage at OUT, and the amplifier (A) will increase the voltage at VGATE. When VOUT is higher than VIN + VRTO, the internal power source for the LTC4411 (VDD) will be diverted to source current from the OUT pin. At the same time VGATE will be pulled to VDD, which will turn off P1. 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 NORMAL OPERATION REVERSE BIASED current is drawn from IN to sense the potential VIN. During reverse turn-off mode the STAT pin will sink 10µA to indicate that the diode is not conducting. When the CTL input is asserted (high), P1 will have its gate voltage pulled high, and the STAT pin will sink 10µA. A 3µA pull-down current on the CTL pin will ensure a low level at this input if it is left open circuited. The overtemperature condition is detected when the internal die temperature increases beyond 150°C. The overtemperature condition will cause the gate amplifier (A) as well as P1 to be shut off. When the internal die temperature cools to below 140°C, the amplifier will turn on and revert to normal operation. Note that prolonged operation under overtemperature conditions will degrade reliability. ISTAT = 10µA DIODE OFF VCTL > VIH VIN – VOUT < VFWD CONTROL SHUTDOWN VIN – VOUT > VFWD ISTAT = 0 CONSTANT VON DIODE ON REGULATION VCTL < VIL VDD < 2.3 IOUT > IFWD IOUT < IFWD ISTAT = 0 CONSTANT RON DIODE ON REGULATION VDD > 2.4 TJ > 150°C IOUT > IMAX IOUT < IMAX ISTAT = 0 CONSTANT ION DIODE ON REGULATION ISTAT = 10µA DIODE OFF TJ < 140°C WHERE: VDD = MAX {VIN, VOUT} VIL = VTH – VHYST/2 VIH = VTH + VHYST/2 UNDER VOLTAGE LOCK-OUT ISTAT = 0 DIODE OFF ISTAT = 0 OVER DIODE OFF TEMPERATURE SHUTDOWN 4411 F04 Figure 4. State Transition Diagram U W U U APPLICATIO S I FOR ATIO INTRODUCTION Automatic PowerPath Control The LTC4411 is intended for power control applications that include low loss diode ORing, 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. Figure 1 illustrates an application circuit for automatic switchover of a load between a battery and a wall adapter or other power input. With initial application of the battery, the load will be charged up as the LTC4411 turns on. The LTC4411 will control the gate voltage of its internal MOSFET to reduce the MOSFET’s voltage drop to a low forward voltage (VFWD). The system is now in the forward regula4411fa 6 LTC4411 U U W U APPLICATIO S I FOR ATIO tion mode, the forward voltage will be kept low by controlling the gate voltage of the internal MOSFET to react to changes in load current. Should the wall adapter input be applied, the Schottky diode will pull up the output voltage, connected to the load, above the battery voltage. The LTC4411 will sense that the output voltage is higher than the battery voltage and will turn off the internal MOSFET. The STAT pin will then sink current indicating an auxiliary input is connected. The battery is now supplying no load current and all load current flows through the Schottky diode. Microcontrolled PowerPath Monitoring and Control Figure 6 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, monitors each supply input and commands the LTC4411 through the CTL input. Back-toback MOSFETs are used so that the parasitic drain-source diode will not power the load when the MOSFET is turned off (dual MOSFETs in one package are commercially available). turn off and no load current will be drawn from the batteries. The STAT pins provide information as to which input is supplying the load current. This concept can be expanded to more power inputs. Multiple Battery Charging Figure 7 illustrates an application circuit for automatic dual battery charging from a single charger. Whichever battery has the lower voltage will receive the charging current until both battery voltages are equal, then both will be charged. When both are charging simultaneously, the higher capacity battery will get proportionally higher current from the charger. For Li-Ion batteries, both batteries will achieve the float voltage minus the forward regulation voltage of 40mV. This concept can apply to more than two batteries. The STAT pin provides information as to which batteries are being charged. For intelligent control, the CTL pin input can be used with a microcontroller as shown in Figure 5. WALL ADAPTER INPUT CIN 1µF 2 BAT1 AUXILIARY P-CHANNEL MOSFETS AUXILIARY POWER SOURCE R1 470k 2 BAT2 1 C1 10µF 2 3 C1: C0805C106K8PAC C2: C1206C475K8PAC 5 IN OUT LTC4411 GND CTL 3 OUT LTC4411 GND IN CTL STAT VCC 470k OUT LTC4411 GND VCC 470k WHEN BOTH STATUS LINES ARE HIGH, THEN BOTH BATTERIES ARE SUPPLYING LOAD CURRENT. WHEN BOTH STATUS LINES ARE LOW, THEN WALL ADAPTER IS PRESENT AND SUPPLYING FULL LOAD CURRENT STATUS IS HIGH WHEN BAT2 IS SUPPLYING LOAD CURRENT STAT C2 4.7µF TO LOAD STATUS IS HIGH WHEN BAT1 IS SUPPLYING LOAD CURRENT 4 IN CTL COUT 4.7µF 5 LOAD CIN: C0805C105K8PAC COUT: C1206C475K8PAC 4 STAT 3 1 CIN 1µF MICROCONTROLLER PRIMARY POWER SOURCE 1 STATUS 4411 F05 Figure 5. Automatic Switchover of Load Between a Primary and an Auxiliary Power Source with External Dual P-Channel MOSFETs Figure 6. Dual Battery Load Sharing with Automatic Switchover of Load from Batteries to Wall Adapter BATTERY CHARGER INPUT 1 OUT LTC4411 2 GND Load Sharing Figure 6 illustrates an application circuit for dual battery load sharing with automatic switchover of load from batteries to wall adapter. Whichever battery is capable of supplying the higher voltage will provide the load current until it is discharged to the voltage of the other battery. The load will then be shared between the two batteries according to the capacity of each battery. The higher capacity battery will provide proportionally higher current to the load. When a wall adapter input is applied, both LTC4411s 4411 F06 3 IN CTL STAT TO LOAD OR PowerPath CONTROLLER 5 VCC BAT1 470k 4 STATUS IS HIGH WHEN BAT1 IS CHARGING TO LOAD OR PowerPath CONTROLLER 1 2 3 IN OUT LTC4411 GND CTL STAT BAT2 VCC 470k STATUS IS HIGH WHEN BAT2 IS CHARGING 4411 F07 Figure 7. Automatic Dual Battery Charging from a Single Charging Source 4411fa 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. 7 LTC4411 U W U U APPLICATIO S I FOR ATIO High Side Power Switch SUPPLY INPUT CIN 1µF Figure 8 illustrates an application circuit for a logic controlled high side power switch. When the CTL pin is a logical low, the LTC4411 will turn on, supplying current to the load. When the CTL pin is a logical high, the LTC4411 will turn off and deny power to the load. If the load is powered from another (higher voltage) source, the supply connected to VIN remains disconnected from the load. U PACKAGE DESCRIPTIO 1 5 IN OUT LTC4411 2 GND 3 LOGIC INPUT TO COUT LOAD 4.7µF 4 CTL STAT CIN: C0805C105K8PAC COUT: C1206C475K8PAC 4411 F08 Figure 8. Logic Controlled High Side Power Switch S5 Package 5-Lead Plastic TSOT-23 (Reference LTC DWG # 05-08-1635) 0.62 MAX 0.95 REF 2.90 BSC (NOTE 4) 1.22 REF 1.4 MIN 3.85 MAX 2.62 REF 2.80 BSC 1.50 – 1.75 (NOTE 4) PIN ONE RECOMMENDED SOLDER PAD LAYOUT PER IPC CALCULATOR 0.30 – 0.45 TYP 5 PLCS (NOTE 3) 0.95 BSC 0.80 – 0.90 0.20 BSC 0.01 – 0.10 1.00 MAX DATUM ‘A’ 0.30 – 0.50 REF 0.09 – 0.20 (NOTE 3) NOTE: 1. DIMENSIONS ARE IN MILLIMETERS 2. DRAWING NOT TO SCALE 3. DIMENSIONS ARE INCLUSIVE OF PLATING 4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR 5. MOLD FLASH SHALL NOT EXCEED 0.254mm 6. JEDEC PACKAGE REFERENCE IS MO-193 1.90 BSC S5 TSOT-23 0302 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, ThinSOT 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 Gauging, C/10 Charge Termination LTC4350 Hot Swappable Load Share Controller Allows N + 1 Redundant Supply, Equally Loads Multiple Power Supplies Connected in Parallel LTC4412/LTC4412HV PowerPath Controller in ThinSOT More Efficient than Diode OR’ing, Automatic Switching Between DC Sources, Simplified Load Sharing, 3V ≤ VIN ≤ 36V (LTC4412HV) 4411fa 8 Linear Technology Corporation LT/LT 0305 REV A • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com © LINEAR TECHNOLOGY CORPORATION 2003