AS3020 800mA Linear Battery Charger In SOT23-5LPackage DESCRIPTION FEATURES AS3020 is a complete constant - current and Programmable Charge Current Up to 800mA constant-voltage linear charger for single cell No MOSFET, Sense Resistor or Blocking Diode lithium-ion and Lithium-Polymer batteries. Its SOT23-5L Package and low external component Required Constant-Current/Constant-Voltage Operation count make AS3020 ideally suited for portable with Thermal Protection to Maximize Charge applications. Furthermore the AS3020 is specifically Rate without Risk of Overheating designed to work within USB power specification. At Charges Single Cell Li-Ion Batteries Directly the same time AS3020 can also be used in the from USB Port standalone lithium-ion and Lithium-polymer battery Press 4.2V Charge Voltage with ± 1% Accuracy charger. 25μA. Supply Current in Shutdown No external sense resistor is needed and no 2.9V Trickle Charge Threshold blocking diode is required due to the internal Available Without Trickle Charge MOSFET architecture. Thermal feedback regulates Soft-Start Limits Inrush Current the charge current to limit the die temperature during Available in SOT23-5L Package high power operation or high ambient temperature. The charge voltage is fixed at 4.2V and the charge APPLICATIONS current can be programmed externally with a single Cellular Telephones, resistor. The A3020 automatically terminates the PDA’s, MP3 Players charge cycle when the charge current drops to Charging Docks and Cradles 1/10th the programmed value after the final float Bluetooth Applications voltage is reached. “ANI” and “ANISEM” is Trademarks of ANISEM Semiconductor, Inc. When the input supply (wall adapter or USB supply) is removed the AS3020 automatically enters a low TYPICAL APPLICATION current stage dropping the battery drain current to VIN 4.5V to 6.5V less than 2μA. The AS3020 can be put into shutdown mode reducing the supply current to 25μA. Other features include charge current monitor, undervoltage lockout, automatic recharge and a 4 VCC LED status pin to indicate termination and the presence of an input voltage. ORDER INFORMATION Part Number Operating Temperature AS3020EGT -40°C to 85°C AS3020 BAT 330 PROG 1 CHRG 3 4.2V Li-lon Batery 5 1.65K GND 2 EVALUATION BOARD Board Number Dimensions EV3020EG-00A 50mmX x 50mmY x 1.4mmZ AS3020 Rev.1.6 10/25/2009 www.anisem.com ANISEM Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2008 ANISEM All Rights Reserved. 1 AS3020 – 800mA LINEAR BATTERY CHARGER ABSOLUTE MAXIMUM RATINGS(1) PACKAGE REFERENCE VCC Supply Voltage………………..……………7V PROG Voltage ……………...………….VCC +0.3V PROG Current…………………………….…800uA CHRG Voltage ………………….………………..7V BAT Voltage ……………………..………………..7V BAT Current…………………………………800mA Junction Temperature ……………….……….. 125°C Lead Temperature (Soldering, 10sec.) …..…+300°C Storage Temperature Range …….... -65℃ to 150°C Part Number* Package Operating Temp AS3020EGT SOT23-5L -40°C to 85°C Recommended Operating Conditions(2) Supply Voltage VIN……………….………-0.3V to 7V Operating Temperature ……………. -40°C to 85°C NOTEs: 1) Exceeding these ratings may damage the device. 2) The device is not guaranteed to function outside of its operating conditions. 3) Measure on approximately 1’’square of 1 oz copper. ELECTRICAL CHARACTERISTICS VIN =5V, TA = 25°C, Unless otherwise noted. PARAMETER CONDITIONS Supply Voltage MIN TYP 4.25 Supply Current 6.5 V 300 2000 uA Standby Mode 200 500 uA 25 50 uA VCC<VBAT or VCC<VUV BAT Current UNITS Charge Mode, RPROG=9K Shutdown Mode(RPROG unconnected, Regulated Output Voltage MAX IBAT=40mA 4.158 4.2 4.242 V RPROG=9K, Current Mode 93 100 107 mA RPROG=1.8K, Current Mode 465 500 535 mA Standby Mode, VBAT=4.2V 0 -2.5 -6 uA Shutdown Mode 1 2 uA Sleep Mode, VCC=0V 1 2 uA Trickle Charge Current VBAT<VTRIK1, RPROG=1.8K 20 45 70 mA Trickle Charge Threshold RPROG=9K, VBAT Rising 2.8 2.9 3.0 V Trickle Voltage Hysteresis RPROG=9K 60 80 110 mV VCC UVLO Threshold From Vcc Low to High 3.7 3.8 3.93 V 150 200 300 mV PROG Pin Rising 1.15 1.21 1.30 V PROG Pin Falling 0.9 1.0 1.1 V VCC from Low to High 70 100 140 mV VCC from High to Low 5 30 50 mV VCC UVLO Hysteresis Manual Shutdown Threshold VCC-VBAT Lockout Threshold AS3020 Rev.1.6 10/25/2009 www.anisem.com ANISEM Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2008 ANISEM All Rights Reserved. 2 AS3020 – 800mA LINEAR BATTERY CHARGER ELECTRICAL CHARACTERISTICS VIN =5V, TA = 25°C, Unless otherwise noted. PARAMETER CONDITIONS MIN TYP MAX UNITS C/10 Termination Current RPROG=9K 0.085 0.10 0.115 mA/mA Threshold RPROG=1.8K 0.085 0.10 0.115 mA/mA PROG Pin Voltage RPROG=9K, Current Mode 0.93 1.0 1.07 V CHRG Pull-down Current VCHRG=5V 8 20 35 uA CHRG Output Low Voltage ICHRG=5mA 0.35 0.6 V Recharge Battery Threshold VFLOAT-VRECHRG 100 200 mV PIN FUNCTIONS PIN NUMBER PIN NAME FUNCTION Open-Drain Charge Status Output. When the battery is charging. The CHRG Pin is 1 CHRG pulled low by an internal N-channel MOSFET. When the charge cycle is completed, a weak pull-down of approximately 20uA is connected to the CHRG pin, indicating an “AC Present” condition. 2 GND 3 BAT 4 VCC 5 PROG AS3020 Rev.1.6 10/25/2009 Ground. Charge Current Output. Provides charge current to the3 battery and regulates the final float voltage to 4.2V. Input Supply Voltage. Provides power to the charger. VCC can range from 4.25 to 6.5 and should be bypassed with at least a 1uF capacitor. Charge Current Program. Charge current Monitor and Shutdown Pin. www.anisem.com ANISEM Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2008 ANISEM All Rights Reserved. 3 AS3020 – 800mA LINEAR BATTERY CHARGER FUNCTION BLOCK DIAGRAM AS3020 Rev.1.6 10/25/2009 www.anisem.com ANISEM Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2008 ANISEM All Rights Reserved. 4 AS3020 – 800mA LINEAR BATTERY CHARGER OPERATION The charge current out of the BAT pin can be The AS3020 is a single cell lithium-lon battery determined at any time by monitoring the PROG pin charger using a constant-current/constant-voltage voltage using the following equation: algorithm. It can deliver up to 800mA of charger current(using a good thermal PCB layout) with a final float voltage accuracy of ± 1%. The AS3020 includes an internal P-MOSFET and IBAT= VPROG * 900 RPROG thermal regulation circuitry. No blocking diode or external CHARGE TERMINATION current sense resistor is required; thus, the basic A charge cycle is terminated when the charge charger external current falls to 1/10th the programmed value after the components. Furthermore, the AS3020 is capable of final float voltage is reached. This condition is operating from a USB power source. detected by using an internal, filtered comparator to circuit requires only two monitor the PROG pin. When the PROG pin voltage NORMAL CHARGER CYCLE falls below 100mV for longer than tTERM(typically A charge cycle begins when the voltage at the VCC 1ms), charging is terminated. The charge current is pin rises above the UVLO threshold level and a 1% latched off and the AS3020 enters standby mode, program resistor is connected from the PROG pin to where the input supply current drops to 200mA (note: ground or when a battery is connected to the charger C/10 termination is disabled in trickle charging and output. If the BAT pin is less than 2.8V, the charger thermal limiting modes).When charging, transient enters constant-current is supplied to the battery. loads on the BAT pin can cause the PROG pin to fall When the BAT pin approaches the final float below 100mV for short periods to 1/10th the voltage(4.2V), the AS3020 enters constant-voltage programmed value. The 1ms filter time(tTERM) on the mode and the charge current begins to decrease. termination comparator ensures that transient loads When the charge current drops to 1/10 of the of this nature do not result in premature charge cycle programmed value, the charge cycle ends. termination. Once the average charge current drops below 1/10th the programmed value, the AS3020 PROGRAMMING CHARGE CURRENT terminates the charge cycle and ceases to provide The charge current is programmed using a single any current through the BAT pin. In this state, all resistor from the PROG pin to ground. The battery loads on the BAT pin must be supplied by the battery. charge current is 1100 times the current out of the The AS3020 constantly monitors the BAT pin voltage PROG pin. The program resistor and the charge in standby mode. If this voltage drops below the current are calculated using the following equations: 4.05V recharge threshold, another charge cycle begins and current is once again supplied to the RPROG= 900V 900V , ICHG= ICHG RPROG AS3020 Rev.1.6 10/25/2009 battery. www.anisem.com ANISEM Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2008 ANISEM All Rights Reserved. 5 AS3020 – 800mA LINEAR BATTERY CHARGER OPERATION(Continued) UNDERVOLTAGE LOCKOUT(UVLO) To manually restart a charge cycle when in standby An internal undervoltage lockout circuit monitors the mode, the input voltage must be removed and input voltage and keeps the charger in shutdown reapplied, or the charger must be shut down and mode until Vcc rises above the undervoltage lockout restarted using the PROG pin. Figure1 shows the threshold.The UVLO circuit has a built-in hysteresis state diagram of a typical charge cycle. of 200mV. Furthermore, to protect against reverse current in the power MOSFET, the UVLO circuit CHARGE STATUS INDICATOR(CHRG) keeps the charger in shutdown mode if Vcc falls to The charge status output has three different states: with 30mV of the battery voltage. If the UVLO strong pull-down 10mA, weak pull-down 20uA, and comparator is tripped, the charger will not come out high of shutdown mode until Vcc rises 100mV above the impedance. The strong pull-down state indicates that the AS3020 is in a charge cycle. Once battery. the charge cycle has terminated, The pin state is determined by undervoltage lockout conditions. A weak pull-down indicates that VCC meets the UVLO conditions and the AS3020 is ready to charge. High impedance indicates that the AS3020 is in undervoltage lockout mode: either Vcc is less than 100mV above the BAT pin voltage or insufficient voltage is applied to the Vcc pin. THERMAL LIMITING An internal thermal feedback loop reduces the programmed charge current if the die temperature attempts to rise above a preset value of approximately 120 ℃ . This feature protects the AS3020 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 AS3020. The charge current can be Figure1. Status Diagram of A Typical Charge Cycle set according to typical(not worst-case) ambient temperature with the assurance that the charger will automatically reduce the current in worst-case conditions. AS3020 Rev.1.6 10/25/2009 www.anisem.com ANISEM Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2008 ANISEM All Rights Reserved. 6 AS3020 – 800mA LINEAR BATTERY CHARGER APPLICATION INFORMATION STABILITY CONSIDERATIONS The constant-voltage mode feedback loop is stable without an output capacitor provided a battery is connected to the charge 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. In constant-current mode, the PROG pin is in the feedback loop, not the battery. The constant-current mode 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 20k. However, additional capacitance on this mode reduces the maximum allowed program resistor. The pole frequency at the PROG pin should be kept above 100kHz. 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 charge input to a live power source. Adding a 1.5Ω resistor in series with a ceramic capacitor will minimize start-up voltage transients. AS3020 Rev.1.6 10/25/2009 POWER DISSIPATION The conditions that cause the AS3020 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= VCC-VBAT * IBAT The approximate ambient temperature at which the thermal feedback begins to protect the IC is TA=120 - PD*θJA TA=120 - VCC- VBAT *IBAT*θJA THERMAL CONSIDERATIONS Because of the small size of the thin SOT23 package, it is very important to use a good thermal PC board layout to maximize the available charge current. The thermal path for the heat generated by the IC is from the die to the cooper lead frame, through the package leads, (especially the ground lead) to the PC board copper. The PC board copper is the heat sink. The footprint copper pads should be as wide as possible and expand out to larger copper areas to spread and dissipate the heat to the surrounding ambient. Other heat sources on the board, not related to the charger, must also be considered when affect overall temperature rise and the maximum charge current. www.anisem.com ANISEM Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2008 ANISEM All Rights Reserved. 7 AS3020 – 800mA LINEAR BATTERY CHARGER PACKAGE DESCRIPTION Package 5-Lead Plastic SOT23-5L 2.70min 3.10max 5 4 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 2 3 0.95REF 0.30min 0.55max 1.90REF AS3020 Rev.1.6 10/25/2009 0.45REF 0.6REF 10°max www.anisem.com ANISEM Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2008 ANISEM All Rights Reserved. 8 AS3020 – 800mA LINEAR BATTERY CHARGER © ANISEM Semiconductor Co., Ltd ANISEM assume responsibility for use of any circuitry other than circuitry entirely embodied in an ANISEM product. No circuit patent licenses, copyrights, mask work rights, or other intellectual property rights are implied. ANISEM reserves the right to make changes to their products or specifications or to discontinue any product or service without notice. Customers are advised to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. ANISEM warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with ANISEM’s standard warranty. Testing and other quality control techniques are utilized to the extent ANISEM deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed. AS3020 Rev.1.6 10/25/2009 www.anisem.com ANISEM Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2008 ANISEM All Rights Reserved. 9 EV3020-r1.0 800mA Linear Battery Charger FEATURES GENERAL DESCRIPTION Programmable Charge Current Up to 800mA AS3020 is a complete constant - current and No MOSFET, Sense Resistor or Blocking Diode constant-voltage Required lithium-ion Constant-Current/Constant-Voltage Operation SOT23-5L Package and low external component count with Thermal Protection to Maximize Charge make AS3020 ideally suited for portable applications. Rate without Risk of Overheating Furthermore the AS3020 is specifically designed to Charges Single Cell Li-Ion Batteries Directly work within USB power specification. At the same time from USB Port AS3020 can also be used in the standalone lithium-ion Press 4.2V Charge Voltage with ± 1% Accuracy and Lithium-polymer battery charger. 25μA. Supply Current in Shutdown No external sense resistor is needed and no blocking 2.9V Trickle Charge Threshold diode is required due to the internal MOSFET Available Without Trickle Charge architecture. Thermal feedback regulates the charge Soft-Start Limits Inrush Current current to limit the die temperature during high power Available in SOT23-5L Package operation or high ambient temperature. The charge and linear charger Lithium-Polymer for single cell batteries. Its voltage is fixed at 4.2V and the charge current can be programmed externally with a single resistor. The APPLICATIONS A3020 automatically terminates the charge cycle when Cellular Telephones, the charge current drops to 1/10th the programmed PDA’s, MP3 Players value after the final float voltage is reached. Charging Docks and Cradles When the input supply (wall adapter or USB supply) is Bluetooth Applications removed the AS3020 automatically enters a low current stage dropping the battery drain current to less TYPICAL APPLICATION than 2μA. The AS3020 can be put into shutdown mode reducing the supply current to 25μA. VIN 4.5V to 6.5V Other features include charge current monitor, undervoltage lockout, automatic recharge and a status 4 VCC LED pin to indicate termination and the presence of an input voltage. AS3020 BAT 330 PROG 1 CHRG 3 4.2V Li-lon Batery 5 1.65K GND 2 600mA single cell Li-lon Charger EV3020 Rev.10 7/25/2008 www.anisem.com ANISEM Proprietary Information. Unauthorized Photocopy and Duplication Prohibited. © 2008 ANISEM All Rights Reserved. 1