LP4057B6F

Preliminary Datasheet LP4057 600mA Standalone Linear Li-Ion Battery Charger General Description Features The LP4057 is a complete constant-current/constant- voltage  Programmable Charge Current Up to 600mA linear charger for single cell lithium-ion batteries. Its  No MOSFET, Sense Resistor or Blocking Diode Required package and low external component count make the LP4057 ideally  Constant-Current/Constant-Voltage Operation with suited for portable applications. Furthermore, the LP4057 is specifically designed to work within USB power specifications. No external sense resistor is needed, and no blocking diode is required due to the internal MOSFET architecture. Thermal feedback regulates the charge current to limit the die temperature during high power operation or high ambient Thermal Regulation to Maximize  Charge Rate Without Risk of Overheating  4.2V Charge Voltage with ± 1% Accuracy  Charge Current Monitor Output for Gas Gauging  Automatic Recharge temperature. The charge voltage is fixed at 4.2V, and the  3V Trickle Charge Threshold charge current can be programmed externally with a single  Charging OTP resistor. The LP4057 automatically terminates the charge cycle  Package in SOT23-6 when the charge current drops to 1.5/10th the programmed value after the final float voltage is reached. When the input supply (wall adapter or USB supply) is removed, the LP4057 Applications automatically enters a low current state, dropping the battery  Portable Media Players/MP3 players drain current to less than 1µA. Other features include charge  Cellular and Smart mobile phone current monitor, automatic recharge and a status pin to indicate  PDA/DSC charge termination and the presence of an input voltage. Bluetooth Applications Marking Information Order Information LP4057 Part Marking Package Shipping LPS LP4057B6F F: Pb-Free Package Type B6 : SOT23-6 BMYWX LPS SOT23-6 3K/REEL BCYWX Marking indication: Y:Production year W:Production week X:Production batch.  LP4057-01 Sep.-2021 Email: marketing@lowpowersemi.com www.lowpowersemi.com Page 1 of 8 Preliminary Datasheet LP4057 Functional Pin Description SOT23-6 Package Type Pin Configurations CHRG 1 6 ISET GND 2 5 FULL BAT 3 4 IN SOT23-6 (Top View) Pin Name Description Open-Drain Charge Status Output. When the battery is charging, the CHRG 1 CHRG pin is pulled low by an internal N-channel MOSFET. When the charge cycle is completed, the pin is pulled High. 2 GND 3 BAT 4 IN Ground. Charge Current Output. Provides charge current to the battery and regulates the final float voltage to 4.2V. Positive Input Supply Voltage. Open-Drain Charge Status Output. When the battery is charging, the FULL pin 5 FULL is pulled High by an internal N-channel MOSFET. When the charge cycle is completed, the pin is pulled Low. Charge Current Program and Charge Current Monitor Pin. The charge current is programmed by connecting a 1% resistor, RISET, to ground. When charging in 6 ISET constant-current mode, this pin servos to 1V. In all modes, the voltage on this pin can be used to measure the charge current using the following formula: IBAT=1000/RISET LP4057-01 Sep.-2021 Email: marketing@lowpowersemi.com www.lowpowersemi.com Page 2 of 8 Preliminary Datasheet LP4057 Typical Application Circuit LP4057B6F VIN 4 IN BAT VBAT 3 RIN 1Ω VIN 6 CIN 10uF ISET 2K RSET FULL 2 GND CBAT 10uF CHRG 5 1 LED1 LED2 Functional Block Diagram CC/CV REGULATOR IN 3.8V BAT UVLO SOFT-STRAT BAT CV LOOP CHRG FULL CHARGER CONTROL CHARGE STATE (LP4057B6F) VRECHAGR RECHARGE BAT 3V TDIE TRICKLE CHARGE 125℃ 100mV 1V TERMINATION 1000/IBAT GND ISET LP4057-01 Sep.-2021 Email: marketing@lowpowersemi.com www.lowpowersemi.com Page 3 of 8 Preliminary Datasheet LP4057 Absolute Maximum Ratings Note1  Input to GND(VIN) --------------------------------------------------------------------------------------------------- -0.3V to 10V  Other Pin to GND ------------------------------------------------------------------------------------------------------ -0.3V to 8V  BAT Short-circuit Duration ------------------------------------------------------------------------------------------- Continuous  Maximum Junction Temperature (TJ)  Maximum Soldering Temperature (at leads, 10 sec) ---------------------------------------------------------------------------------- 125℃ -------------------------------------------------------------- 260℃ Note1. Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Thermal Information  Maximum Power Dissipation (, TA=25°C) ----------------------------------------------------------------------------- 0.45W  Thermal Resistance (JA) ------------------------------------------------------------------------------------------------ 250℃/W ESD Susceptibility  HBM(Human Body Model) ---------------------------------------------------------------------------------------------------- 2KV  MM(Machine Model) ------------------------------------------------------------------------------------------------------------ 200V Recommended Operating Conditions  Ambient Temperature Range ------------------------------------------------------------------------------------ -20℃ to 85℃ LP4057-01 Sep.-2021 Email: marketing@lowpowersemi.com www.lowpowersemi.com Page 4 of 8 Preliminary Datasheet LP4057 Electrical Characteristics (TA = 25℃. VIN = 5V, unless otherwise noted.) SYMBOL PARAMETER VIN Adapter/USB Voltage Range IIN Input Supply Current Standby Mode (Charge Terminated) VFLOAT Regulated Output (Float) Voltage IBAT = 40mA IBAT BAT Pin Current CONDITIONS MIN TYP. MAX UNITS 4.5 5 6.5 V 50 4.158 4.2 RISET = 10K，Current Mode 100 RISET = 2K，Current Mode 500 Standby Mode, VBAT = 4.2V Sleep Mode, VIN = 0V uA 4.242 V mA ±1 uA VTRIKL Trickle Charge Threshold Voltage RISET = 10k, VBAT Rising 3 V VTRHYS Trickle Charge Hysteresis Voltage RISET = 10K 150 mV ITRIKL Trickle charge current VBAT < VTRIKL, RISET =10K 40 VBAT < VTRIKL, RISET=2K 200 VUV VIN Undervoltage Lockout Threshold From VIN Low to High 3.8 V VUVHYS VIN Undervoltage Lockout Hysteresis 200 mV VASD VIN–VBAT Lockout Threshold Voltage 150 mV ITERM C/10 Termination Current Threshold 15 % IBAT VISET ISET Pin Voltage RISET = 10K,Charge Mode 1 V VSTAT STAT1/STAT2 Pin Output Low Voltage ISTAT = 5mA 0.5 V ISTAT STAT1/2 Pin Weak Pull-Down Current ICHRG = 5V 5 uA ΔVRECHRG Recharge Battery Threshold Voltage VFLOAT - VRECHRG LP4057-01 Sep.-2021 Email: marketing@lowpowersemi.com 200 www.lowpowersemi.com mA mV Page 5 of 8 Applications Information The LP4057 is a single cell lithium-ion battery charger using a constant-current/constant-voltage algorithm. It can deliver up to 600mA of charge current (using a good thermal PCB layout) with a final float voltage accuracy of ± 1%. The LP4057 includes an internal P-channel power MOSFET and thermal regulation circuitry. No blocking diode or external current sense resistor is required; thus, the basic charger circuit requires only three external components. Furthermore, the LP4057 is capable of operating from a USB power source. Normal Charge Cycle A charge cycle begins when the voltage at the VIN pin rises Charge Status Indicator (CHRG/FULL) The charge status output has two different states: strong pull-down (~5mA) and high impedance. The strong pull-down state indicates that the LP4057 is in a charge cycle. High impedance indicates that the charge cycle complete or the LP4057 is in under voltage lockout mode: either VIN is less than 150mV above the BAT pin voltage or insufficient voltage is applied to the IN pin. A microprocessor can be used to distinguish between these two states. Charge Stage CHRG FULL Charging Low High Charge Complete High Low above the UVLO threshold level and a 1% program resistor is connected from the ISET pin to ground or when a battery is connected to the charger output. If the BAT pin is less than 2.9V, the charger enters trickle charge mode. When 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 LP4057 enters constant-voltage mode and the charge current begins to decrease. When the charge current drops to 1.5/10 of the programmed value the charge cycle ends. Charge Termination A charge cycle is terminated when the charge current falls to 1.5/10th the programmed value after the final float voltage is reached. This condition is detected by using an internal, filtered comparator to monitor the ISET pin. When the ISET pin voltage falls below 100mV for longer than TTERM (typically 1ms), charging is terminated. The charge current is latched off and the LP4057 enters standby mode, where the input supply current drops to 50µA. When charging, transient loads on the BAT pin can cause the ISET pin to fall below 150mV for short Programming Charge Current periods of time before the DC charge current has dropped to The charge current is programmed using a single resistor 1.5/10th the programmed value. The 1ms filter time (TTERM) on from the ISET pin to ground. The battery charge current is the termination comparator ensures that transient loads of this 1000 times the current out of the ISET pin. The program nature do not result in premature charge cycle termination. resistor and the charge current are calculated using the Once the average charge current drops below 1.5/10th the following equations: programmed value, the LP4057 terminates the charge cycle RISET=1000÷IBAT, and ceases to provide any current through the BAT pin. In this state, all loads on the BAT pin must be supplied by the battery. IBAT=1000÷RISET The LP4057 constantly monitors the BAT pin voltage in The charge current out of the BAT pin can be determined at standby mode. If this voltage drops below the 4.0V recharge any time by monitoring the ISET pin voltage using the threshold (VRECHRG), another charge cycle begins and current following equation: is once again supplied to the battery. To manually restart a IBAT=VISET÷RISET×1000 LP4057-01 Sep.-2021 charge cycle when in standby mode, the input voltage must be removed and reapplied. Email: marketing@lowpowersemi.com www.lowpowersemi.com Page 6 of 8 Thermal Limit IN Bypass Capacitor An internal thermal feedback loop reduces the programmed Many types of capacitors can be used for input bypassing; charge current if the die temperature attempts to rise above a however, caution must be exercised when using multilayer preset value of approximately 125℃. This feature protects the ceramic capacitors. Because of the self-resonant and high Q LP4057 from excessive temperature and allows the user to characteristics of some types of ceramic capacitors, high push the limits of the power handling capability of a given voltage transients can be generated under some start-up circuit board without risk of damaging the LP4057. The charge conditions, such as connecting the charger input to a live current can be set according to typical (not worst-case) power source. Adding a 1.5Ω resistor in series with an X5R ambient temperature with the assurance that the charger will ceramic capacitor will minimize start-up voltage transients. automatically reduce the current in worst-case conditions. Automatic Recharge Layout Considerations  Once the charge cycle is terminated, the LP4057 continuously monitors the voltage on the BAT pin using a comparator with keep their traces short and wide.  a 2ms filter time (TRECHARGE). A charge cycle restarts when the battery voltage falls below 4.0V (which corresponds to For the main current paths as indicated in bold lines, Put the input capacitor as close as possible to the device pins (IN and GND).  Connect all analog grounds to a command node and approximately 80% to 90% battery capacity). This ensures then connect the command node to the power ground that the battery is kept at or near a fully charged condition and behind the output capacitors. eliminates the need for periodic charge cycle initiations. CHRG output enters a strong pull-down state during recharge cycles. Power Dissipation The conditions that cause the LP4057 to reduce charge current through thermal feedback can be approximated by considering the power dissipated in the IC. Nearly all of this power dissipation is generated by the internal MOSFET—this is calculated to be approximately: PD=(VIN－VBAT) × IBAT LP4057-01 Sep.-2021 Email: marketing@lowpowersemi.com www.lowpowersemi.com Page 7 of 8 Packaging Information SOT23-6 A D B C A1 b 1.00 2.60 e H 0.95 L 0.5 Recommended Land Pattern SYMBOL MILLIMETER MIN NOM MAX A 0.889 1.100 1.295 A1 0.000 0.050 0.152 B 1.397 1.600 1.803 b 0.28 0.35 0.559 C 2.591 2.800 3.000 D 2.692 2.920 3.120 e LP4057-01 0.95BSC H 0.080 0.152 0.254 L 0.300 0.450 0.610 Sep.-2021 Email: marketing@lowpowersemi.com www.lowpowersemi.com Page 8 of 8