LP4055 POWER | Alldatasheet
Document overview
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Technical content
Features
Programmable Charge Current Up to 800mA No MOSFET, Sense Resistor or Blocking Diode Required Protection of Reverse Connection of Battery Constant-Current/Constant-Voltage Operation with Thermal Regulation to Maximize Charge Rate Without Risk of Overheating 4.2V /4.35V Charge Voltage with ± 1% Accuracy Charge Current Monitor Output for Gas Gauging Automatic Recharge 2.9V Trickle Charge Threshold C/10 Charge Termination Output OCP Charging OTP
Applications
Portable Media Players/MP3 players Cellular and Smart mobile phone PDA/DSC Bluetooth Applications Marking Information Part Marking Package Shipping LP4055B5F LP4055QVF LPS BBYWX SOT23-5 TDFN-6 3K/REEL Marking indication: Y:Production year W:Production week X:Production batch.
LP4055-03 Apr.-2017 Email: marketing@lowpowersemi.com www.lowpowersemi.com Page 2 of 8 Preliminary Datasheet LP4055 Typical Application Circuit Functional Pin Description Package Type Pin Configurations SOT23-6 / TDFN-6
4 VCC
Open-Drain Charge Status Output. When the battery is charging, the CHRG pin is pulled low by an internal N -channel MOSFET. When the LP4055 detects an under voltage lockout condition or charge complete, CHRG is forced high impedance. 2 5,7 GND Ground. 3 4 BAT Charge Current Output. Provides charge current to the battery and regulates the final float voltage to 4.2V. An internal precision resistor divider from this pin sets the float voltage. 4 3 VCC Positive Input Supply Voltage. Provide power to the charger. V CC can range from 4.5V to 6.5V and should be bypassed with at least a 1µF capacitor. When VCC drops to within 30mV of the BAT pin voltage, the LP4055 enters shutdown mode, dropping IBAT to less than1µA. 5 1 PROG Charge Current Program and Charge Current Monitor Pin. The charge current is programmed by connecting a 1% resistor to ground（RPROG）. When charging in 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/RPROG - 2 FULL Open-Drain Charge Complete Status Output. When the battery charge complete, the FULL pin is pulled low by an internal N -channel MOSFET. When the LP4055 is charging, FULL is forced high impedance. 10uF BATTERY GREEN RED 10uF CHRG CHRG_OK GND PROG VCC BATT LP4055QVF VIN 2.7K
LP4055-03 Apr.-2017 Email: marketing@lowpowersemi.com www.lowpowersemi.com Page 3 of 8 Preliminary Datasheet LP4055 Absolute Maximum Ratings Note 1 Note 1. Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Thermal Information ESD Susceptibility
LP4055-03 Apr.-2017 Email: marketing@lowpowersemi.com www.lowpowersemi.com Page 4 of 8 Preliminary Datasheet LP4055
Electrical Characteristics
(TA=25℃. VCC=5V, LP4055B5F,the specifications which apply over the full operating temperature range, unless otherwise noted.) Symbol Parameter Condition Min Typ Max Units VCC Adapter/USB Voltage Range 4.5 5 6.5 V ICC Input Supply Current Charge Mode, RPROG = 10k 300 1000 μA Standby Mode (Charge Terminated) 50 200 Shutdown Mode (RPROG NC, VCC<VBAT, or VCC<VUV) VFLOAT Regulated Output (Float) Voltage 0℃≤TA≤85℃, LP4055B5F 4.158 4.2 4.242 V IBAT BAT Pin Current RPROG=10k, Current Mode 80 100 120 mA RPROG=2k, Current Mode 400 500 600 Reverse Current, VBAT=-4.2V -1 Standby Mode, VBAT=4.2V Shutdown Mode (RPROG NC) Sleep Mode, VCC=0V μA VTRIKL Trickle Charge Threshold Voltage RPROG=10k, VBAT Rising 2.8 2.9 3.0 V VTRHYS Trickle Charge Hysteresis Voltage RPROG=10k 60 80 110 mV VUV VCC Undervoltage Lockout Threshold From VCC Low to High 3.7 3.8 3.95 V VUVHYS VCC Undervoltage Lockout Hysteresis 500 mV VASD VCC–VBAT Lockout Threshold Voltage 100 mV ITERM Termination Current Threshold RPROG=10k 10 %IBAT RPROG=2k 10 VPROG PROG Pin Voltage RPROG=10k, Charge Mode 1 V VCHRG/FULL CHRG/FULL Pin Output Low Voltage ICHRG/FULL=5mA 0.35 0.6 V ICHRG/FULL CHRG/FULL Pin Weak Pull-Down Current VCHRG/FULL=5V 5 uA ΔVRECHRG Recharge Battery Threshold Voltage VFLOAT-VRECHRG 100 150 200 mV TLIM Junction Temperature in Constant Temperature Mode 150 ℃ RON Power FET “ON” Resistance (Between VCC and BAT) 500 mΩ tSS Soft-Start Time IBAT=0 to IBAT=1000V/RPROG 200 μs
LP4055-03 Apr.-2017 Email: marketing@lowpowersemi.com www.lowpowersemi.com Page 5 of 8 Preliminary Datasheet LP4055
Application Information
The LP4055 is a single cell lithium-ion battery charger using a constant-current/constant-voltage algorithm. It can deliver up to 800mA of charge current (using a good thermal PCB layout) with a final float voltage accuracy of ± 1%. The LP4055 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 LP4055 is capable of operating from a USB power source. Normal Charge Cycle A charge cycle begins when the voltage at the VCC pin rises above the UVLO threshold level and a 1% program resistor is connected from the PROG 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 to bring the battery voltage up to a safe level for full current charging. 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 LP4055 enters constant-voltage mode and the charge current begins to decrease. The charge cycle ends when the charge current drops to 1/10 of the programmed value. Programming 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 using the following equations: RPROG=1000V/IBAT IBAT=1000V/RPROG The charge current out of the BAT pin can be determined at any time by monitoring the PRO G pin voltage using the following equation: IBAT=VPROG/RPROG×1000 Charge Termination A charge cycle is terminated when the charge current falls to 1/10th the ISET rammed 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 200mV for longer than tTERM(typically 1ms), charging is terminated. The charge current is latched off and the LP28056S enters standby mode, where the input supply current drops to 200µA. In this state, all loads on the BAT pin must be supplied by the battery. (Note: C/10 termination is disabled in trickle charging and therm al limiting modes). 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 LP4055 is in a charge cycle. Once the charge cycle has ter minated, the pin state is determined by under voltage lockout conditions. High impedance indicates that the charge cycle complete or the LP 4055 is in under voltage lockout mode: either V CC is less than 100mV above the BAT pin voltage or insufficient voltage is applied to the VCC pin. A microprocessor can be used to distin guish between these two states. Function CHRG FULL Charging LOW HIGH Charge Complete HIGH LOW Charge Current An internal thermal feedback loop reduces the programmed charge current if the die temperature attempts to rise above a preset value of approximately 150℃. This feature protects the LP4055 from excessive temperature and allows the user to push the limits o f the power handling capability of a given circuit board without risk of damaging the LP4055. The charge current can be set according to typical (not worst -case) ambient temperature with the assurance that the charger will automatically reduce the current in worst -case conditions. SOT power considerations are discussed further in the Applications Information section.
LP4055-03 Apr.-2017 Email: marketing@lowpowersemi.com www.lowpowersemi.com Page 6 of 8 Preliminary Datasheet LP4055 Stability Considerations The constant-voltage mode feedback loop is stable without an output capacitor provided a battery is connected to th e charger output. With no battery present, an output capacitor is recommended to reduce ripple voltage. When using high value, low ESR ceramic capacitors, it is recommended to add a 1Ω resistor in series with the capacitor. No series resistor is needed if tantalum capacitors are used. Manual Shutdown At any point in the charge cycle, the LP4055 can be put into shutdown mode by removing RPROG. This reduces the battery drain current to less than 1µA and the supply current to less than 1µA. A new charge cycle can be initiated by reconnecting the program resistor. The CHRG pin is in a high impedance state if the LP4055 is in undervoltage lockout mode: either V CC is within 100mV of the BAT pin voltage or insufficient voltage is applied to the VCC pin. Automatic Recharge Once the charge cycle is terminated, the LP4055 continuously monitors the voltage on the BAT pin using a comparator with a 2ms filter time ( tRECHRG). A charge cycle restarts when the battery voltage falls below 4.05V (which corresponds to approximately 80% to 90% battery capacity). This ensures that the battery is kept at or near a fully charged condition and eliminates the need for periodic charge c ycle initiations. CHRG output enters a strong pull-down state during recharge cycles. Under voltage Lockout (UVLO) An internal under voltage lockout circuit monitors the input voltage and keeps the charger in shutdown mode until V CC rises above the under voltage lockout threshold .The UVLO circuit has a built -in hysteresis of 500mV. Furthermore, to protect against reverse current in the power MOSFET, the UVLO circuit keeps the charger in shutdown mode if V CC falls to within 30mV of the battery voltage. If the UVLO comparator is tripped, the charger will not come out of shutdown mode until VCC raises 100mV above the battery voltage. Power Dissipation（SOT23-5） The conditions that cause the LP4055 to reduce charge current through thermal feedback can be app roximated 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=(VCC-VBAT)×IBAT Where 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=150℃-PD×θJA TA=150℃-(VCC-VBAT)×IBAT×θJA 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. Layout Considerations For the main current paths as indicated in bold lines, keep their traces short and wide. Put the input and output capacitor as close as possible to the device pins (VCC, BAT and GND). Connect all analog grounds to a command node and then connect the command node to the power ground behind the output capacitors.
LP4055-03 Apr.-2017 Email: marketing@lowpowersemi.com www.lowpowersemi.com Page 7 of 8 Preliminary Datasheet LP4055 Packaging Information SOT23-5
LP4055-03 Apr.-2017 Email: marketing@lowpowersemi.com www.lowpowersemi.com Page 8 of 8 Preliminary Datasheet LP4055 TDFN-6