LTC4063 Standalone Linear Li-Ion Charger with Micropower Low Dropout Linear Regulator U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO Charge Current Programmable up to 1A Integrated 100mA Adjustable Low Dropout Linear Regulator Charges Single Cell Li-Ion Batteries Directly from USB Port Preset Charge Voltage with ±0.35% Accuracy No External MOSFET, Sense Resistor or Blocking Diode Needed Thermal Regulation Maximizes Charge Rate Without Risk of Overheating* Adjustable LDO Output Voltage Range: 1.2V to 4.2V Programmable Charge Termination Timer Programmable Charge Current Detection/Termination SmartStartTM Prolongs Battery Life Charge Status Output 35µA Charger Quiescent Current in Shutdown 15µA LDO Quiescent Current Available in a Low Profile (0.75mm) 10-Lead (3mm × 3mm) DFN Package U APPLICATIO S ■ ■ ■ Handheld Computers Portable MP3 Players Digital Cameras The LTC®4063 is a standalone linear charger for single cell lithium-ion batteries with an adjustable low dropout linear regulator (LDO). The adjustable LDO regulates an output voltage between 1.2V to 4.2V at up to 100mA load current. When the input supply (wall adapter or USB supply) is removed, the LDO regulates the output voltage without interruption. The battery charger and LDO regulator can be enabled individually. No external sense resistor or external blocking diode is required for charging due to the internal MOSFET architecture. Internal thermal feedback regulates the charge current to maintain a constant die temperature during high power operation or high ambient temperature conditions. The float voltage is fixed at 4.2V and the charge current is programmed with an external resistor. Charge termination methods include minimum charge current or maximum time. With power applied, the LTC4063 can be put into shutdown mode to reduce the supply current to 35µA and the battery drain current to less than 2µA. Other features include smart recharge, undervoltage lockout, LDO current limiting and a charge status pin to indicate when the charge cycle has completed. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. SmartStart is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. *Protected by U.S. Patents including 6522118. U TYPICAL APPLICATIO Complete Charge Cycle (900mAh Battery) Single Cell Li-Ion Battery Charger with Regulated 3V Output (C/10 Termination) BAT LTC4063 OUT 1µF + 440k TIMER PROG IDET 715Ω VOUT 3V FB GND 2.2µF 160k 4.2V SINGLE CELL Li-Ion BATTERY 700 CHARGE CURRENT (mA) VCC CONSTANT CURRENT 600 4.50 4.25 500 4.00 400 3.75 300 3.50 200 3.25 100 0 4063 TA01a CONSTANT VOLTAGE VCC = 5V TA = 25°C BATTERY VOLTAGE (V) 700mA VIN 4.3V TO 8V 4.75 800 3.00 2.75 0 0.25 0.50 0.75 1 1.25 1.50 1.75 2 2.25 4063 TA01b TIME (HOURS) 4063fb 1 LTC4063 W U U U W W W ABSOLUTE MAXIMUM RATINGS PACKAGE/ORDER INFORMATION (Note 1) Input Supply Voltage (VCC) ....................... – 0.3V to 10V CHGEN, LDOEN, CHRG ............................. – 0.3V to 10V FB ............................................................... – 0.3V to 8V PROG, IDET, TIMER ...................... – 0.3V to VCC + 0.3V BAT, OUT .................................................... –0.3V to 8V BAT Short-Circuit Duration .......................... Continuous OUT Short-Circuit Duration ......................... Continuous BAT Pin Current (Note 8) .......................................... 1A Maximum Junction Temperature (Note 7) ........... 125°C Operating Temperature Range (Note 2) .. – 40°C to 85°C Storage Temperature Range ................. – 65°C to 125°C ORDER PART NUMBER TOP VIEW 10 VCC BAT 1 OUT 2 FB 3 LDOEN 4 7 TIMER CHGEN 5 6 CHRG LTC4063EDD 9 PROG 11 8 IDET DD PART MARKING DD PACKAGE 10-LEAD (3mm × 3mm) PLASTIC DFN LBHX TJMAX = 125°C, θJA = 40°C/W (NOTE 3) EXPOSED PAD (PIN 11) IS GROUND MUST BE SOLDERED TO PCB Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: http://www.linear.com/leadfree/ Consult factory for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The ● indicates the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VCC = 5V, unless otherwise noted. SYMBOL PARAMETER CONDITIONS VCC VCC Supply Voltage ICC ICC Supply Current VFLOAT VBAT Regulated Output Voltage IBAT BAT Pin Current (Note 5) RPROG = 10k, Constant-Current Mode RPROG = 1.25k, Constant-Current Mode Standby Mode, Charge Terminated Shutdown Mode (CHGEN = 5V, LDOEN = 5V) VPROG PROG Pin Voltage RPROG = 10k, Constant-Current Mode RPROG = 1.25k, Constant-Current Mode VCHRG CHRG Output Low Voltage ICHRG = 5mA ITRIKL Trickle Charge Current VBAT < VTRIKL, RPROG = 10k VBAT < VTRIKL, RPROG = 1.25k VTRIKL Trickle Charge Threshold Voltage VUV MIN TYP MAX 8 V 400 100 35 15 800 200 65 30 µA µA µA µA 4.185 4.170 4.2 4.2 4.215 4.230 V V 93 760 100 800 –3.5 ±1 107 840 –7 ±2 mA mA µA µA 0.97 0.97 1 1 1.03 1.03 V V 0.35 0.6 V 6 60 10 80 14 100 mA mA VBAT Rising Hysteresis 2.8 2.9 100 3 V mV VCC Undervoltage Lockout Voltage From Low to High Hysteresis 3.7 3.8 200 3.9 V mV VASD VCC – VBAT Lockout Threshold Voltage VCC from Low to High, VBAT = 4.2V VCC from High to Low, VBAT = 4.2V 145 10 180 45 220 75 mV mV VCHGEN CHGEN Input Threshold Voltage CHGEN Rising, 4.3V < VCC < 8V Hysteresis 0.4 0.7 100 1 V mV RCHGEN CHGEN Pin Pull-Down Resistor 1.2 2 5 MΩ VCT Charge Termination Mode Threshold Voltage VTIMER from High to Low Hysteresis 0.4 0.7 100 1 V mV VUT User Termination Mode Threshold Voltage VTIMER from Low to High Hysteresis 4.15 4.1 100 4.5 V mV ● Charge Mode (Note 4), RPROG = 10k Standby Mode, Charge Terminated Shutdown (CHGEN = 5V, VCC < VBAT or VCC < VUV) CHGEN = 5V and LDOEN = 5V 4.3 ● ● ● ● 0°C ≤ TA ≤ 85°C ● ● ● ● ● UNITS 4063fb 2 LTC4063 ELECTRICAL CHARACTERISTICS The ● indicates the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VCC = 5V, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS IDETECT Charge Current Detection Threshold RDET = 1k, 0°C ≤ TA ≤ 85°C RDET = 2k, 0°C ≤ TA ≤ 85°C RDET = 10k, 0°C ≤ TA ≤ 85°C RDET = 20k, 0°C ≤ TA ≤ 85°C 90 45 8.5 4 100 50 10 5 110 55 11.5 6 mA mA mA mA ∆VRECHRG Recharge Threshold Voltage VFLOAT – VRECHRG, 0°C ≤ TA ≤ 85°C 75 100 125 mV tTERM Termination Comparator Filter Time Current Termination Mode 1 1.5 2.2 ms tRECHRG Recharge Comparator Filter Time tTIMER Charge Cycle Time CTIMER = 0.1µF tSS Soft-Start Time IBAT from 0 to ICHG TLIM 3 7 14 2.55 3 3.45 ms Hour 100 µs Junction Temperature in Constant Temperature Mode 105 °C RON Power FET “ON” Resistance (Between VCC and BAT) 375 mΩ VBAT-LDO LDO Supply Voltage (BAT) IBAT-LDO LDO Supply Current (from BAT) 2.65 4.4 V VCC < VBAT, IOUT = 0mA VCC > VBAT, IOUT = 0mA (Note 6) 15 9 25 18 µA µA IBAT-LDO-SD LDO Supply Current in Shutdown VBAT = 4.4V 2.5 5 µA VFB FB Regulated Voltage VBAT = 3.7V, IOUT = 1mA ● 800 816 mV VFB(LINE) VFB Line Regulation VBAT = 2.65V to 4.4V, IOUT = 1mA ● 1 4 mV VFB(LOAD) VFB Load Regulation IOUT = 1mA to 100mA, VBAT = 4.4V ● 1 4 mV VLDOEN LDOEN Input Threshold Voltage (Rising) LDOEN Rising, VBAT = 4.4V Hysteresis 0.4 0.7 100 1 V mV RLDOEN LDOEN Pin Pull-Down Resistor 1.2 2 5 MΩ VDO LDO Dropout Voltage IOUT = 100mA, VOUT = 3V 125 200 mV VLDOUVLO LDO Undervoltage Lockout Threshold VBAT from High to Low Hysteresis 2.45 2.55 100 2.65 V mV IFB FB Pin Current –25 0 25 nA ISC Short-Circuit Output Current VOUT = 0V 500 mA VNO(RMS) Output Voltage Noise VOUT = 3V, IOUT = 100mA, COUT = 2.2µF, 10Hz ≤ f ≤ 100kHz 135 µVRMS ● 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 LTC4063EDD is guaranteed to meet performance specifications from 0°C to 70°C. Specifications over the – 40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls. Note 3: Failure to correctly solder the Exposed Pad of the package to the PC board will result in a thermal resistance much higher than 40°C/W. Note 4: Supply current includes PROG pin current and IDET pin current (approximately 100µA each) but does not include any current delivered to the battery through the BAT pin (approximately 100mA). 784 Note 5: Does not include LDO supply current. Note 6: The LDO is partially powered from VCC, thus reducing the supply current from the BAT pin. Note 7: 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 8: Defined by long term current density limitations. 4063fb 3 LTC4063 TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C unless otherwise noted. Regulated Output (Float) Voltage vs Charge Current Regulated Output (Float) Voltage vs Temperature 4.215 VCC = 5V RPROG = 1.25k 4.24 4.210 VCC = 8V 4.205 VFLOAT (V) 4.20 4.18 4.16 RPROG = 10k 1.004 4.22 VFLOAT (V) 1.006 RPROG = 10k 4.200 1.002 VPROG (V) 4.26 PROG Pin Voltage vs Temperature (Constant-Current Mode) VCC = 4.3V VCC = 8V 1.000 VCC = 4.3V 4.195 0.998 4.190 0.996 4.14 4.12 4.10 4.185 –50 100 200 300 400 500 600 700 800 CHARGE CURRENT (mA) 0 –25 0 25 50 TEMPERATURE (°C) 75 Charge Current vs PROG Pin Voltage –25 0 25 50 TEMPERATURE (°C) 195 100 CHRG Pin I-V Curve 35 CTIMER = 0.1µF VCC = 5V VBAT = 4V 30 190 TA = –40°C TA = 25°C 600 500 400 300 25 185 ICHRG (mA) tTIMER (MINUTES) 700 IBAT (mA) 75 4063 G03 Internal Charge Timer vs Temperature VCC = 5V RPROG = 1.25k VTIMER = 5V 800 0.994 –50 4063 G02 4063 G01 900 100 VCC = 4.3V 180 175 VCC = 8V TA = 90°C 20 15 10 200 170 5 100 165 –50 –25 0 0.2 0 0.4 0.6 0.8 1.0 1.2 VPROG (V) 0 50 25 75 0 TEMPERATURE (°C) 100 Trickle Charge Current vs Temperature Trickle Charge Threshold Voltage vs Temperature 2.96 VCC = 5V VBAT = 2.5V RPROG = 1.25k 2.94 86 4 3 VCHRG (V) 2 5 6 7 Charge Current vs Battery Voltage 1000 VCC = 5V RPROG = 1.25k 800 2.92 VTRIKL (V) ITRIKL (mA) 1 4063 G06 84 82 IBAT (mA) 88 0 4063 G05 4063 G04 90 125 2.90 600 400 2.88 80 76 –50 200 2.86 78 –25 50 25 0 TEMPERATURE (°C) 75 100 4063 G07 2.84 –50 –25 0 25 50 TEMPERATURE (°C) 75 100 4063 G08 0 VCC = 5V RPROG = 1.25k θJA = 40°C/W 2.7 3 3.3 3.6 3.9 VBAT (V) 4.2 4.5 4063 G09 4063fb 4 LTC4063 TYPICAL PERFORMANCE CHARACTERISTICS Charge Current vs Ambient Temperature 1000 900 ONSET OF THERMAL REGULATION 800 Recharge Threshold Voltage vs Temperature Charge Current vs Supply Voltage 4.16 RPROG = 1.25k VBAT = 3.3V θJA = 35°C/W TA = 25°C 800 RPROG = 1.25k 4.14 RPROG = 2k 400 200 V = 5V CC VBAT = 4V θJA = 40°C/W 0 50 25 0 75 –50 –25 TEMPERATURE (°C) 4.12 ONSET OF THERMAL REGULATION 600 400 4.06 125 4 4.5 5 5.5 6 7 6.5 7.5 70 VCC = 5V VCC = 8V 850 40 VCC = 5V 30 VCC = 4.3V VCHGEN (mV) ICC (µA) 450 750 650 10 0 –50 125 800 700 20 400 –25 50 25 0 TEMPERATURE (°C) 600 –50 –25 100 75 4063 G13 803 VBAT = 4.2V 802 TA = 25°C 800 TA = 90°C TA = –40°C 798 –25 50 25 0 TEMPERATURE (°C) 75 100 4063 G16 797 0 20 40 TA = 115°C 60 80 IOUT (mA) 100 VBAT = 4.2V 800 799 799 1.8 1.6 –50 VFB (V) VFB (mV) RCHGEN (MΩ) 801 801 2.0 ILOAD = 1mA 802 2.6 2.2 125 FB Pin Regulated Voltage vs Temperature 803 2.8 100 4063 G15 FB Pin Regulated Voltage vs Output Current 3.0 2.4 50 25 75 0 TEMPERATURE (°C) 4063 G14 CHGEN Pin Pull-Down Resistance vs Temperature 100 900 50 550 100 75 CHGEN Pin Threshold Voltage (On-to-Off) vs Temperature CHGEN = VCC LDOEN = 0V 60 500 0 25 50 TEMPERATURE (°C) 4063 G12 Shutdown Current vs Temperature VBAT = 4V IBAT = 200mA RPROG = 1.25k 50 25 75 0 TEMPERATURE (°C) –25 4063 G11 650 RDS(ON) (mΩ) 4.04 –50 8 VCC (V) Power FET On Resistance vs Temperature 350 –50 –25 VCC = 8V 4.08 4063 G10 600 VCC = 4.3V 4.10 500 300 100 VRECHRG (V) IBAT (mA) IBAT (mA) 700 600 VBAT = 2.65V 798 120 4063 G17 797 –50 –25 50 25 75 0 TEMPERATURE (°C) 100 125 4063 G18 4063fb 5 LTC4063 TYPICAL PERFORMANCE CHARACTERISTICS LDO Regulator Dropout Voltage vs Temperature 25 VOUT = 3V IOUT = 100mA 20 VBAT = 4.2V IBAT (µA) VDROPOUT (mV) 150 100 15 VBAT = 2.65V 10 50 5 0 –50 –25 0 25 50 TEMPERATURE (°C) 75 0 –50 100 –25 50 0 25 TEMPERATURE (°C) 4063 G19 75 100 10 1 0.1 0.01 10 100 1k 10k FREQUENCY (Hz) LDOEN Pin Pull-Down Resistance vs Temperature LDOEN Pin Threshold (On-to-Off) vs Temperature 3.0 900 VOUT = 3V 100k 4063 G24 4060 G20 LDO Regulator Dropout Voltage vs Load Current 180 LDO Regulator Output Noise Spectral Density OUTPUT NOISE SPECTRAL DENSITY (µV/√Hz) 200 LDO Regulator Quiescent Current vs Temperature VBAT = 4V 150 2.8 850 TA = 115°C TA = 90°C 90 60 0 0 20 40 60 80 LOAD CURRENT (mA) 750 700 TA = 25°C TA = –40°C 30 800 RLDOEN (MΩ) VLDOEN (mV) VDROPOUT (mV) 2.6 120 120 2.2 2.0 650 100 2.4 1.8 600 –50 –25 50 25 75 0 TEMPERATURE (°C) 4063 G26 100 125 1.6 –50 –25 50 25 0 TEMPERATURE (°C) VOUT 500µV/ DIV 100 4063 G23 4063 G22 LDO Regulator 10Hz to 100kHz Output Noise 75 LDO Regulator Transient Response 135µVRMS OUTPUT VOLTAGE DEVIATION 50mV/DIV LOAD CURRENT 50mA/DIV COUT = 2.2µF ILOAD = 100mA VOUT = 3V 10ms/DIV 4063 G21 COUT = 2.2µF VOUT = 1.2V 50µs/DIV 4063 G28 4063fb 6 LTC4063 U U U PI FU CTIO S BAT (Pin 1): Charger Output and Regulator Input. This pin provides charge current to the battery and regulates the final float voltage to 4.2V. This pin also supplies power to the LDO regulator. OUT (Pin 2): LDO Regulator Output. This pin should be bypassed with a ≥ 2µF low ESR capacitor as close to the pin as possible for best performance. The minimum VOUT is 1.2V. FB (Pin 3): Regulator Feedback Input. The voltage on this pin is compared to the internal reference voltage (800mV) by the error amplifier to keep the output voltage in regulation. An external resistor divider between OUT and FB sets the output voltage. LDOEN (Pin 4): LDO Enable Input. A logic high on the LDOEN pin shuts down the LDO. In this state, OUT becomes high impedance and the battery drain current drops to less than 5µA. A logic low on the LDOEN pin enables the LDO regulator. A 2M pull-down resistor defaults the LDO to its enabled state. CHGEN (Pin 5): Charger Enable Input. A logic high on the CHGEN pin places the charger into shutdown mode, where the ICC quiescent current is less than 65µA. A logic low on this pin enables battery charging. A 2M pull-down resistor to ground defaults the charger to its enabled state. CHRG (Pin 6): Open-Drain Charge Status Output. The charge status indicator pin has two states: pull-down and high impedance. This output can be used as a logic interface or an LED driver. In the pull-down state, an NMOS transistor capable of sinking 10mA pulls down on the CHRG pin. The state of this pin is dependent on the value of IDETECT as well as the termination method being used. See Applications Information. TIMER (Pin 7): Timer Program and Termination Select Pin. This pin selects which method is used to terminate the charge cycle. Connecting a capacitor, CTIMER, to ground selects Charge Time termination. The charge time is set by the following formula: Connecting the pin to ground selects Charge Current termination, while connecting the pin to VCC selects User termination. See Applications Information. IDET (Pin 8): Current Detection Threshold Program Pin. The current detection threshold, IDETECT, is set by connecting a resistor, RDET, to ground. IDETECT is set by the following formula: IDETECT = RDET = RPROG 100 V • ICHG = or 10RDET RDET 100 V IDETECT The CHRG pin becomes high impedance when the charge current drops below IDETECT. IDETECT can be set to 1/10th the programmed charge current by connecting IDET directly to PROG. See Applications Information. This pin is clamped to approximately 2.4V. Driving this pin to voltages beyond the clamp voltage can draw large currents and should be avoided. PROG (Pin 9): Charge Current Program and Charge Current Monitor. The charge current is set by connecting a resistor, RPROG, to ground. When charging in constant current mode, this pin servos to 1V. The voltage on this pin can be used to measure the charge current using the following formula: IBAT = VPROG • 1000 RPROG VCC (Pin 10): Positive Input Supply Pin. Provides power to the battery charger. This pin should be bypassed with a 1µF capacitor. Exposed Pad (Pin 11): Ground. This pin is the back of the Exposed Pad package and must be soldered to the PCB copper for minimal thermal resistance. CTIMER or 0.1µF Time (Hours) CTIMER = 0.1µF • 3 (Hours) Time (Hours) = 3 Hours • 4063fb 7 LTC4063 W BLOCK DIAGRA 10 VCC – TO BAT 1000× + 4.1V 6 1× 1× C1 – CHRG BAT + MA STOP OUT 1 2 RECHRG 4 LDOEN CA LDOEN – 2MΩ LOGIC 5 CHGEN VA + RA + – FB 1V 800mV 1.2V CHGEN TERM 3 R2 0.1V VCC 2MΩ R1 + – 3µA SEL C2 + C3 – – + 2.9V TO BAT COUNTER 0.1V OSCILLATOR + TDIE – 105°C TA SHDN IDET TIMER 7 8 PROG 9 GND 11 4063 BD CTIMER RDET RPROG 4063fb 8 LTC4063 U OPERATIO The LTC4063 is designed to charge a single cell lithiumion battery and supply a regulated output voltage for battery-powered applications. Using the constant current/constant voltage algorithm, the charger can deliver up to 1A of charge current with a final float voltage accuracy of ±0.35%. The LTC4063 includes an internal P-channel power MOSFET and thermal regulation circuitry. No blocking diode or external sense resistor is required; thus, the basic charger circuit requires only two external components. The LDO regulator is powered from the battery terminal and can be programmed for output voltages between 1.2V and 4.2V using external resistors. An output capacitor is required on the OUT pin for stability and improved transient response. A low ESR capacitor of ≥2µF should be used. Normal Operation The charge cycle begins when the voltage at the VCC pin rises above the UVLO level and a discharged battery is connected to BAT. If the BAT pin voltage is below 2.9V, the charger enters trickle charge mode. In this mode, the LTC4063 supplies 1/10th of the programmed charge current in order to bring the battery voltage up to a safe level for full current charging. Once the BAT pin voltage rises above 2.9V, the charger enters constant-current mode where the programmed charge current is supplied to the battery. When the BAT pin approaches the final float voltage (4.2V), the LTC4063 enters constant-voltage mode and the charge current decreases as the battery becomes fully charged. The LTC4063 offers several methods with which to terminate a charge cycle. Connecting an external capacitor to the TIMER pin activates an internal timer that stops the charge cycle after the programmed time period has elapsed. Grounding the TIMER pin and connecting a resistor to the IDET pin causes the charge cycle to terminate once the charge current falls below a set threshold when the charger is in constant-voltage mode. Connecting the TIMER pin to VCC disables internal termination, allowing external charge termination to be used by the CHGEN input. See Applications Information for more on charge termination methods. Programming the Charge Current The charge current is programmed using a single resistor from the PROG pin to ground. The battery charge current is 1000 times the current out of the PROG pin. The program resistor and the charge current are calculated by the following equations: RPROG = 1000 V 1000 V , ICHG = ICHG RPROG The charge current out of the BAT pin can be determined at any time by monitoring the PROG pin voltage and applying the following equation: IBAT = VPROG • 1000 RPROG SmartStart When the LTC4063 is initially powered on or brought out of shutdown mode, the charger checks the voltage on BAT. If the BAT pin is below the recharge threshold of 4.1V (which corresponds to approximately 80% to 90% battery capacity), the LTC4063 enters charge mode and begins a full charge cycle. If the BAT pin is above 4.1V, the LTC4063 enters standby mode and does not begin charging. This feature reduces the number of unnecessary charge cycles, prolonging battery life. Automatic Recharge When the charger is in standby mode, the LTC4063 continuously monitors the voltage on the BAT pin. When the BAT pin voltage drops below 4.1V, the charge cycle is automatically restarted and the internal timer is reset to 50% the programmed charge time (if time termination is being used). This feature eliminates the need for periodic charge cycle initiations and ensures that the battery is always fully charged. Automatic recharge is disabled in User Termination mode. Thermal Regulation An internal thermal feedback loop reduces the programmed charge current if the die temperature attempts to rise above a preset value of approximately 105°C. This feature 4063fb 9 LTC4063 U OPERATIO protects the LTC4063 from excessive temperature and allows the user to push the limits of the power handling capability of a given circuit board without risk of damaging the LTC4063. The charge current can be set according to typical (not worst-case) ambient temperatures with the assurance that the charger will automatically reduce the current in worst-case conditions. Undervoltage Lockout (UVLO) An internal undervoltage lockout circuit monitors the input voltage and keeps the charger in shutdown mode until VCC rises above the undervoltage lockout threshold (3.8V). The UVLO circuit has a built-in hysteresis of 200mV. Furthermore, to protect against reverse current in the power MOSFET, the UVLO circuit keeps the charger in shutdown mode if VCC falls to less than 45mV above the battery voltage. Hysteresis of 135mV prevents the charger from cycling in and out of shutdown. Manual Shutdown At any point in the charge cycle, the charger can be put into shutdown mode by pulling the CHGEN pin high. This reduces the supply current to less than 65µA and the battery drain current of the charger to less than 2µA. A new charge cycle can be initiated by pulling the CHGEN pin low. Pulling the LDOEN pin high puts the LDO into shutdown mode reducing the battery drain current of the LDO to less than 5µA. When both the CHGEN and LDOEN pins are pulled high, the total battery drain current from the LTC4063 is less than 2µA. If shutdown is not required, leaving these pins disconnected continuously enables the circuit. Trickle Charge and Defective Battery Detection When the BAT pin voltage is below the 2.9V trickle charge threshold (VTRIKL), the charger reduces the charge current to 10% of the programmed value. If the battery remains in trickle charge for more than 25% of the total programmed charge time, the charger stops charging and enters a FAULT state, indicating that the battery is defective.1 The LTC4063 indicates the FAULT state by driving the CHRG open-drain output with a square wave. The duty cycle of this oscillation is 50% and the frequency is set by CTIMER: fCHRG = 0.1µF • 3.1Hz CTIMER An LED driven by the CHRG output exhibits a blinking pattern, indicating to the user that the battery needs replacing. To exit the FAULT state, the charger must be restarted either by toggling the CHGEN input or removing and reapplying power to VCC. Charge Status Output (CHRG) The charge status indicator pin has two states: pull-down and high impedance. In the pull-down state, an NMOS transistor pulls down on the CHRG pin and can sink up to 10mA. A pull-down state indicates that the LTC4063 is charging a battery and the charge current is greater than IDETECT (which is set by the external resistor RDET). A high impedance state indicates that the charge current has dropped below IDETECT. In the case where the IDET pin is left open (RDET = ∞, IDETECT = 0), a high impedance state on CHRG indicates that the LTC4063 is not charging. Low Dropout Linear Regulator (LDO) The OUT pin provides a stable, regulated output voltage powered from the battery. This output can power devices such as memory or USB controllers from the battery when there is no power applied to VCC. The LDO can deliver 100mA of current with a nominal dropout voltage of 150mV. It is designed to be stable with a low ESR capacitor greater than 2µF on the OUT pin. Furthermore, the LDO is capable of operating from a Li-Ion battery voltage as low as 2.65V with less than 300mV of dropout over the specified operating conditions. An undervoltage lockout circuit automatically disables the LDO when the battery voltage drops below 2.55V, reducing the battery drain current to less than 5µA. The LDO can be disabled by pulling the LDOEN pin high, reducing the battery quiescent current to less than 5µA. 1The defective battery detection feature is only available when time termination is being used. 4063fb 10 LTC4063 U OPERATIO BAT SINGLE CELL Li-Ion BATTERY VOUT OUT R2 LTC4063 + COUT FB GND anywhere between 1.2V and 4.2V, although the upper limit is limited by the battery voltage minus the regulator dropout voltage. R1 ⎛ R2 ⎞ VOUT = 800mV • ⎜ 1 + ⎟ ⎝ R1⎠ 4063 F01 Figure 1. Adjustable Linear Regulator Figure 1 shows how an external resistor divider sets the regulator output voltage. The output voltage can be set In order to maintain stability under light load conditions, the maximum recommended value of R1 is 160k. U W U U APPLICATIO S I FOR ATIO Programming Charge Termination The LTC4063 terminates a charge cycle using several methods, allowing the designer considerable flexibility in choosing an ideal charge termination algorithm. Table 1 shows a brief description of the different termination methods and their behavior. Charge Time Termination Connecting a capacitor (CTIMER) to the TIMER pin enables the timer and selects Charge Time Termination. The total charge time is set by: Time (Hours) = 0.1µF • 3 Hours CTIMER When the programmed time has elapsed, the charge cycle terminates and the charger enters standby mode. Subsequent recharge cycles terminate when half the programmed time has elapsed. The IDET pin determines the behavior of the CHRG output. Connecting a resistor (RDET) from the IDET pin to ground sets the charge current detection threshold, IDETECT: IDETECT = RPROG 100 V • ICHG = 10RDET RDET or RDET = 100 V IDETECT Table 1 METHOD Charge Time Termination Charge Current Termination User-Selectable Charge Termination TIMER 0.1µF to GND IDET CHARGER DESCRIPTION CHRG OUTPUT DESCRIPTION RDET to Charges for 3 Hours. After 3 Hours, the Charger Pull-Down State While IBAT > IDETECT. High Impedance Stops Charging and Enters Standby Mode. GND State While IBAT < IDETECT or When Charging is Stopped Recharge Cycles Last for 1.5 Hours 0.1µF to GND NC GND RDET to GND GND Charges for 3 Hours. After 3 Hours, the Charger Pull-Down State When Charging. High Impedance State Stops Charging and Enters Standby Mode. When Charging is Stopped Recharge Cycles Last for 1.5 Hours Charges Until Charge Current Drops Below IDETECT, Then Enters Standby Mode Pull-Down State When Charging. High Impedance State When Charging is Stopped NC Charges Indefinitely Until CHGEN Pin is Pulled High Pull-Down State When Charging. High Impedance State When Charging is Stopped VCC RDET to GND Charges Indefinitely Until CHGEN Pin is Pulled High. SmartStart is Disabled Pull-Down State While IBAT > IDETECT. High Impedance State While IBAT < IDETECT or When Charging is Stopped VCC NC Charges Indefinitely Until CHGEN Pin is Pulled High. SmartStart is Disabled Pull-Down State When Charging. High Impedance State When Charging is Stopped 4063fb 11 LTC4063 U W U U APPLICATIO S I FOR ATIO When the charge current (IBAT) is greater than IDETECT, the CHRG output is in its pull-down state. When the charger enters constant-voltage mode operation and the charge current falls below IDETECT, the CHRG output becomes high impedance, indicating that the battery is almost fully charged. The CHRG output will also become high impedance once the charge time elapses. If the IDET pin is not connected, the CHRG output remains in its pulldown state until the charge time elapses and terminates the charge cycle. Figure 2 shows a charger circuit using charge time termination that is programmed to charge at 500mA. Once the charge current drops below 100mA in constant-voltage mode (as set by RDET), the CHRG output turns off the LED. This indicates to the user that the battery is almost fully charged and ready to use. The LTC4063 continues to charge the battery until the internal timer reaches 3 hours (as set by CTIMER). During recharge cycles, the LTC4063 charges the battery until the internal timer reaches 1.5 hours. Figure 3 describes the operation of the LTC4063 charger when Charge Time Termination is used. 500mA VIN VCC BAT LTC4063 CHRG PROG RPROG 2k IDET RDET 1k + TIMER GND CTIMER 0.1µF 4063 F02 Figure 2. Charge Time Termination. The Charger Automatically Shuts Off After 3 Hours POWER ON FAULT MODE NO CHARGE CURRENT CHRG STATE: SQUARE WAVE 1/4 CHARGE TIME ELAPSES CHGEN = 0V OR UVLO CONDITION STOPS TRICKLE CHARGE MODE 1/10 FULL CURRENT CHRG STATE: PULL-DOWN BAT < 2.9V BAT > 2.9V CHARGE MODE SHUTDOWN MODE FULL CURRENT ICC DROPS TO 35µA CHRG STATE: 2.9V < BAT < 4.1V PULL-DOWN IF IBAT > IDETECT Hi-Z IF IBAT < IDETECT CHRG STATE: Hi-Z CHARGE TIME ELAPSES STANDBY MODE BAT > 4.1V NO CHARGE CURRENT CHGEN = 5V OR UVLO CONDITION CHRG STATE: Hi-Z BAT < 4.1V RECHARGE MODE FULL CURRENT 1/2 CHARGE TIME ELAPSES CHRG STATE: PULL-DOWN IF IBAT > IDETECT Hi-Z IF IBAT < IDETECT 4063 F03 Figure 3. State Diagram of a Charge Cycle Using Charge Time Termination 4063fb 12 LTC4063 U W U U APPLICATIO S I FOR ATIO Charge Current Termination comparator ensures that transient loads of this nature do not result in premature charge cycle termination. Once the average charge current drops below IDETECT, the charger terminates the charge cycle. Connecting the TIMER pin to ground selects Charge Current Termination. With this method, the timer is disabled and a resistor (RDET) must be connected from the IDET pin to ground. IDETECT is programmed using the same equation stated in the previous section (repeated here for convenience): IDETECT = The CHRG output is in its pull-down state when charging and in its high impedance state once charging has stopped. Figure 4 describes the operation of the LTC4063 charger when charge current termination is used. RPROG 100 V • ICHG = 10RDET RDET User-Selectable Charge Termination or RDET = Connecting the TIMER pin to VCC selects User-Selectable Charge Termination, in which all internal termination features are disabled. The charge cycle continues indefinitely until the charger is shut down through the CHGEN pin. The IDET pin programs the behavior of the CHRG output in the same manner as when using Charge Time Termination. Specifically, when the charge current (IBAT) is greater than IDETECT, the CHRG output is in its pull-down state. When the charger enters constant-voltage mode operation and the charge current falls below IDETECT, the CHRG output becomes high impedance, indicating that the battery is charged. If the IDET pin is not connected, the CHRG output remains in its pull-down state until the charger is shut down. 100 V IDETECT The charge cycle terminates when the charge current falls below IDETECT. This condition is detected using an internal, filtered comparator to monitor the IDET pin. When the IDET pin falls below 100mV for longer than tTERM (typically 1.5ms), charging is terminated. When charging, transient loads on the BAT pin can cause the IDET pin to fall below 100mV for short periods of time before the DC current has dropped below the IDETECT threshold. The 1.5ms filter time (tTERM) on the internal POWER ON TRICKLE CHARGE MODE 1/10 FULL CURRENT CHGEN = 0V OR UVLO CONDITION STOPS CHRG STATE: PULL-DOWN BAT < 2.9V BAT > 2.9V 2.9V < BAT < 4.1V CHARGE MODE SHUTDOWN MODE FULL CURRENT ICC DROPS TO 35µA CHRG STATE: Hi-Z CHRG STATE: PULL-DOWN BAT < 4.1V IBAT < IDETECT IN VOLTAGE MODE STANDBY MODE NO CHARGE CURRENT CHRG STATE: Hi-Z BAT > 4.1V 4063 F04 CHGEN = 5V OR UVLO CONDITION Figure 4. State Diagram of a Charge Cycle Using Charge Current Termination 4063fb 13 LTC4063 U W U U APPLICATIO S I FOR ATIO POWER ON CHGEN = 0V OR UVLO CONDITION STOPS TRICKLE CHARGE MODE 1/10 FULL CURRENT SHUTDOWN MODE CHRG STATE: PULL-DOWN ICC DROPS TO 35µA BAT < 2.9V BAT > 2.9V CHRG STATE: Hi-Z CHARGE MODE FULL CURRENT CHRG STATE: 2.9V < BAT PULL-DOWN IF IBAT > IDETECT Hi-Z IF IBAT < IDETECT 4063 F05 CHGEN = 5V OR UVLO CONDITION Figure 5. State Diagram of a Charger Cycle Using User Termination With User-Selectable Charge Termination, the SmartStart feature is disabled; when the charger is powered on or enabled, the LTC4063 automatically begins charging, regardless of the battery voltage. Figure 5 describes charger operation when User-Selectable Charge Termination is used. Programming C/10 Current Detection/Termination In most cases, an external resistor, RDET, is needed to set the charge current detection threshold, IDETECT. However, when setting IDETECT to be 1/10th of ICHG, the IDET pin can 500mA VIN VCC BAT LTC4063 PROG RPROG 2k IDET RDET 2k + TIMER GND 500mA VIN VCC BAT LTC4063 PROG RPROG 1k IDET + TIMER GND 4063 F06 Figure 6. Two Circuits that Charge at 500mA Full-Scale Current and Terminate at 50mA be connected directly to the PROG pin. This reduces the component count, as shown in Figure 6. When PROG and IDET are connected in this way, the fullscale charge current, ICHG, is programmed using a different equation: RPROG = 500 V 500 V , ICHG = ICHG RPROG Stability Considerations The battery charger constant voltage mode feedback loop is stable without any compensation provided a battery is connected. However, a 1µF capacitor with a 1Ω series resistor to GND is recommended at the BAT pin to keep ripple voltage low when the battery is disconnected. When the charger is in constant current mode, the PROG pin is in the feedback loop, not the battery. The constant current stability is affected by the impedance at the PROG pin. With no additional capacitance on the PROG pin, the charger is stable with program resistor values as high as 10k; however, additional capacitance on this node reduces the maximum allowed program resistor. For the LDO regulator, a capacitor (COUT) must be connected from OUT to GND to ensure regulator loop stability. It is recommended that low ESR capacitors be used for COUT to reduce noise on the output of the linear regulator. COUT must be ≥ 2µF for best performance. 4063fb 14 LTC4063 U W U U APPLICATIO S I FOR ATIO Regulator Output Noise Noise measurements on the output should be made with care to ensure accurate results. Coaxial connections and proper shielding should be used to maintain measurement integrity. Figure 7 shows a test setup for taking the measurement. When the output is set to 3V and a 100mA load is applied, the LTC4063 output noise power in the 10Hz to 100kHz band is typically measured to be 135µVRMS. For more information on obtaining accurate noise measurements for LDOs, see Application Note 83. Power Dissipation When designing the battery charger circuit, it is not necessary to design for worst-case power dissipation scenarios because the LTC4063 automatically reduces the charge current during high power conditions. The conditions that cause the LTC4063 to reduce charge current through thermal feedback can be approximated by considering the power dissipated in the IC. Most of the power dissipation is generated from the internal charger MOSFET (the LDO generates considerably less heat in most applications). Thus, the power dissipation is calculated to be approximately: Example: An LTC4063 operating from a 5V wall adapter is programmed to supply 800mA full-scale current to a discharged Li-Ion battery with a voltage of 3.3V. Assuming θJA is 40°C/W (see Thermal Considerations), the ambient temperature at which the LTC4063 will begin to reduce the charge current is approximately: TA = 105°C – (5V – 3.3V) • (800mA) • 40°C/W TA = 105°C – 1.36W • 40°C/W = 105°C – 54.4°C TA = 50.6°C The LTC4063 can be used above 50.6°C ambient, but the charge current will be reduced from 800mA. The approximate current at a given ambient temperature can be approximated by: IBAT = 105°C – TA ( VCC – VBAT ) • θJA Using the previous example with an ambient temperature of 60°C, the charge current will be reduced to approximately: IBAT = 105°C – 60°C 45°C = (5V – 3.3V) • 40°C/W 68°C/A IBAT = 662mA PD = (VCC – VBAT) • IBAT PD is the power dissipated, VCC is the input supply voltage, VBAT is the battery voltage and IBAT is the charge current. The approximate ambient temperature at which the thermal feedback begins to protect the IC is: TA = 105°C – PD • θJA It is important to remember that LTC4063 applications do not need to be designed for worst-case thermal conditions, since the IC will automatically reduce power dissipation when the junction temperature reaches approximately 105°C. TA = 105°C – (VCC – VBAT) • IBAT • θJA 5Hz SINGLE ORDER HIGHPASS IN GAIN = 60dB 10Hz 2nd ORDER BUTTERWORTH HP 100kHz 4th ORDER BUTTERWORTH LP 5Hz SINGLE ORDER HIGHPASS 10Hz TO 100kHz 4063 F07 Figure 7. Filter Structure for Noise Testing LDOs 4063fb 15 LTC4063 U W U U APPLICATIO S I FOR ATIO Protection Features While the thermally regulated charger limits the junction temperature to 105°C during normal operation, current overload at the LDO regulator output may result in excessive power dissipation. Internal circuitry limits the output currents, allowing the battery charger and regulator to be short-circuited to ground indefinitely. Furthermore, if the junction temperature exceeds 150°C, both the battery charger and regulator will shut down. The LTC4063 becomes enabled again once the junction temperature drops below 140°C. If the fault condition remains in place, the part will thermal cycle between the shutdown and enabled states. The LTC4063 also protects against reverse conduction from the LDO output to the battery input. This provides protection if a discharged (low voltage) battery is powering the LDO, and the output voltage is held above the battery voltage by a backup battery or a second regulator circuit. When the output voltage is higher than the battery voltage, the reverse output current is typically less than 50µA. Thermal Considerations In order to deliver maximum charge current under all conditions, it is critical that the exposed metal pad on the backside of the LTC4063 package is properly soldered to the PC board ground. Correctly soldered to a 2500mm2 double sided 1oz copper board, the LTC4063 has a thermal resistance of approximately 40°C/W. Failure to make thermal contact between the exposed pad on the backside of the package and the copper board will result in thermal resistances far greater than 40°C/W. As an example, a correctly soldered LTC4063 can deliver over 800mA to a battery from a 5V supply at room temperature. Without a good backside thermal connection this number would drop to much less than 500mA. VCC Bypass Capacitor Many types of capacitors can be used for input bypassing, however, caution must be exercised when using multilayer ceramic capacitors. Because of the self-resonant and high Q characteristics of some types of ceramic capacitors, high voltage transients can be generated under some start-up conditions such as connecting the charger input to a live power source. Adding a 1.5Ω resistor in series with an X5R ceramic capacitor will minimize start-up voltage transients. For more information, see Application Note 88. Charge Current Soft-Start and Soft-Stop The LTC4063 includes a soft-start circuit to minimize the inrush current at the start of a charge cycle. When a charge cycle is initiated, the charge current ramps from zero to the full-scale current over a period of approximately 100µs. Likewise, internal circuitry slowly ramps the charge current from full-scale to zero when the charger is shut down or self terminates. This has the effect of minimizing the transient current load on the power supply during start-up and charge termination. Reverse Polarity Input Voltage Protection In some applications, protection from reverse polarity voltage on VCC is desired. If the supply voltage is high enough, a series blocking diode can be used. In other cases where the voltage drop must be kept low, a P-channel MOSFET can be used (as shown in Figure 8). DRAIN-BULK DIODE OF FET LTC4063 VIN VCC 4063 F08 Figure 8. Low Loss Input Reverse Polarity Protection 4063fb 16 LTC4063 U W U U APPLICATIO S I FOR ATIO USB and Wall Adapter Power The LTC4063 allows charging from both a wall adapter and a USB port. Figure 9 shows how to combine wall adapter and USB power inputs. A P-channel MOSFET, MP1, is used to prevent back conducting into the USB port when a wall adapter is present and a Schottky diode, D1, is used to prevent USB power loss through the 1k pulldown resistor. 5V WALL ADAPTER ICHG = 800mA USB POWER ICHG = 500mA Most wall adapters can supply more current than the 500mA limited USB port. Therefore, an N-channel MOSFET, MN1, and an extra 3.3k program resistor are used to increase the charge current to 800mA when the wall adapter is present. D1 VCC MP1 SYSTEM LOAD BAT LTC4063 GND IDET + PROG Li-Ion BATTERY 3.3k 1k MN1 2k 1.25k 4063 F09 Figure 9. Combining Wall Adapter and USB Power 4063fb 17 LTC4063 U TYPICAL APPLICATIO S Full-Featured Li-Ion Charger with 2.5V Regulated Output (Using Charge Time Termination) VIN 5V 1µF 1k 10 800mA VCC 1 BAT CHRG LTC4063 2 7 OUT TIMER 9 PROG 6 1.25k 0.1µF 8 FB IDET VOUT 2.5V 2.2µF GND 625Ω + 340k 3 SINGLE CELL Li-Ion BATTERY 160k 11 4063 TA02 USB/Wall Adapter Power Li-Ion Charger (Using Charge Current Termination) 5V WALL ADAPTER 10 USB POWER VCC BAT + Li-Ion CELL LTC4063 1µF 7 TIMER PROG IDET 1k 1 GND 11 9 2.5k 8 100mA/ 500mA 2k 10k µC 4063 TA03 4063fb 18 LTC4063 U PACKAGE DESCRIPTIO 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 R = 0.115 TYP 6 3.00 ±0.10 (4 SIDES) 0.38 ± 0.10 10 1.65 ± 0.10 (2 SIDES) PIN 1 TOP MARK (SEE NOTE 6) (DD10) DFN 1103 5 0.200 REF 1 0.75 ±0.05 0.00 – 0.05 0.25 ± 0.05 0.50 BSC 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 4063fb 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. 19 LTC4063 RELATED PARTS PART NUMBER Battery Chargers DESCRIPTION COMMENTS LTC1733 Monolithic Lithium-Ion Linear Battery Charger Standalone Charger with Programmable Timer, Up to 1.5A Charge Current LTC1734 Lithium-Ion Linear Battery Charger in ThinSOTTM Simple ThinSOT Charger, No Blocking Diode, No Sense Resistor Needed LTC1734L Lithium-Ion Linear Battery Charger in ThinSOT Low Current Version of LTC1734; 50mA ≤ ICHRG ≤ 180mA LTC4002 Switch Mode Lithium-Ion Battery Charger Standalone, 4.7V ≤ VIN ≤ 24V, 500kHz Frequency, 3 Hour Charge Termination LTC4050 Lithium-Ion Linear Battery Charger Controller Features Preset Voltages, C/10 Charger Detection and Programmable Timer, Input Power Good Indication, Thermistor Interface LTC4052 Monolithic Lithium-Ion Battery Pulse Charger No Blocking Diode or External Power FET Required, ≤1.5A Charge Current LTC4053 USB Compatible Monolithic Li-Ion Battery Charger Standalone Charger with Programmable Timer, Up to 1.25A Charge Current LTC4054 Standalone Linear Li-Ion Battery Charger with Integrated Pass Transistor in ThinSOT Thermal Regulation Prevents Overheating, C/10 Termination, C/10 Indicator, Up to 800mA Charge Current LTC4057 Lithium-Ion Linear Battery Charger Up to 800mA Charge Current, Thermal Regulation, ThinSOT Package LTC4058 Standalone 950mA Lithium-Ion Charger in DFN C/10 Charge Termination, Battery Kelvin Sensing, ±7% Charge Accuracy LTC4059 900mA Linear Lithium-Ion Battery Charger 2mm × 2mm DFN Package, Thermal Regulation, Charge Current Monitor Output LTC4060 NiMH/NiCd Standalone Battery Charger 1-/4-Cell Series Batteries, No Microcontroller, No Firmware Required, Termination by –dV, Max Voltage or Max Time, Up to 2A Charge Current LTC4411/LTC4412 Low Loss PowerPathTM Controller in ThinSOT Automatic Switching Between DC Sources, Load Sharing, Replaces ORing Diodes Power Management LTC3405/LTC3405A 300mA (IOUT), 1.5MHz, Synchronous Step-Down DC/DC Converter 95% Efficiency, VIN = 2.7V to 6V, VOUT = 0.8V, IQ = 20µA, ISD < 1µA, ThinSOT Package LTC3406/LTC3406A 600mA (IOUT), 1.5MHz, Synchronous Step-Down DC/DC Converter 95% Efficiency, VIN = 2.5V to 5.5V, VOUT = 0.6V, IQ = 20µA, ISD < 1µA, ThinSOT Package LTC3411 1.25A (IOUT), 4MHz, Synchronous Step-Down DC/DC Converter 95% Efficiency, VIN = 2.5V to 5.5V, VOUT = 0.8V, IQ = 60µA, ISD < 1µA, MS Package LTC3440 600mA (IOUT), 2MHz, Synchronous Buck-Boost DC/DC Converter 95% Efficiency, VIN = 2.5V to 5.5V, VOUT = 2.5V, IQ = 25µA, ISD < 1µA, MS Package ThinSOT and PowerPath are trademarks of Linear Technology Corporation. 4063fb 20 Linear Technology Corporation LT/LWI 0906 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 2004