Description Features SE9016 is a complete constant-current & constant voltage linear charger for single cell lithium-ion and Lithium-Polymer batteries. Its SOT-23 package and low external component count make SE9016 ideally suited for portable applications. Furthermore, the SE9016 is specifically designed to work within USB power specification. At the same time, SE9016 can also be used in the standalone lithium-ion and Lithium-polymer battery chargers. 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 temperature. The charge voltage is fixed at 4.2V, and the charge current can be programmed externally with a single resistor. The SE9016 automatically terminates the charge cycle when the charge current drops to 1/10th the programmed value after the final float voltage is reached. When the input supply (wall adapter or USB supply) is removed, the SE9016 automatically enters a low current stage, dropping the battery drain current to less than 2uA. The SE9016 can be put into shutdown mode, reducing the supply current to 20uA. Other features include charge current monitor, undervoltage lockout, automatic recharge and a status pin to indicate charge termination and the presence of an input voltage. SE9016 is intentionally designed to have slightly negative Tempco. This provides extra protection to Lithium battery during charging. ¾ Programmable Charge Current Up to 800mA. ¾ No MOSFET, Sense Resistor or Blocking Diode Required. ¾ Constant-Current/Constant-Voltage Operation with Thermal Protection to Maximize Charge Rate without Risk of Overheating. ¾ Charges Single Cell Li-Ion Batteries Directly from USB Port. ¾ Preset 4.2V Charge Voltage with ±1% Accuracy. ¾ 20uA Supply Current in Shutdown. ¾ 2.9V Trickle Charge Threshold ¾ Soft-Start Limits Inrush Current. ¾ Available in 5-Lead SOT-23 Package. ¾ RoHS Compliant and 100% Lead (Pb)-Free Application ¾ Cellular Telephones, PDA’s, MP3 Players. ¾ Charging Docks and Cradles ¾ Bluetooth Applications Application Diagram Pin Configuration Revision 6/7/2007 Preliminary and all contents are subject to change without prior notice © Seaward Electronics Inc., 2007. • www.seawardinc.com • Page 1 Absolute Maximum Rating (1) Parameter Symbol Value Units Input Supply Voltage VCC 7 V PROG Voltage VPROG VCC+0.3 V BAT Voltage VBAT 7 V CHRG Voltage VCHRG 7 V BAT Short-Circuit Duration Continuous Thermal Resistance, Junction-to-Ambient ΘJA 250 °C/W BAT Pin Current IBAT 800 mA PROG Pin Current IPROG 800 μA Maximum Junction Temperature TJ 125 °C Storage Temperature TS -65 to +125 °C 300 °C Lead Temperature (Soldering, 10 sec) Operating Rating (2) Parameter Symbol Value Units Supply Input Voltage VIN -0.3 to +7 V Junction Temperature TJ -40 to +85 °C Electrical Characteristics VIN = 5V; TJ = 25°C; unless otherwise specified. Symbol VCC ICC Parameter Conditions Input Supply Voltage Input Supply Current Min Typ 4.25 (3) Max Unit 6 V 500 µA Charge Mode , RPROG = 10k 110 Standby Mode (Charge Terminated) 70 20 40 µA µA 4.158 4.2 4.242 V 90 110 130 mA +/-1 +/-5 mA µA +/-0.5 +/-5 µA +/-1 +/-5 µA Shutdown Mode(RPROG Not Connected, VCC < VBAT, or VCC < VUV) VFLOAT Regulated Output (Float) Voltage IBAT = 30mA, ICHRG = 5mA IBAT BAT Pin Current RPROG = 10k, Current Mode RPROG = 2k, Current Mode Standby Mode, VBAT = 4.2V 500 0 Shutdown Mode (RPROG Not Connected) Sleep Mode, VCC = 0V ITRIKL Trickle Charge Current VBAT < VTRIKL, RPROG = 10k VTRIKL Trickle Charge Threshold Voltage RPROG = 10k, VBAT Rising 10 2.8 Revision 6/7/2007 Preliminary and all contents are subject to change without prior notice © Seaward Electronics Inc., 2007. • www.seawardinc.com • Page 2 2.9 mA 3.0 V Electrical Characteristics (Continued) VIN = 5V; TJ = 25°C; unless otherwise specified Symbol Parameter Conditions VUV VCC Undervoltage Lockout Threshold VUVHYS VCC Undervoltage Lockout Hysteresis VMSD Manual Shutdown Threshold Voltage VASD From VCC Low to High VCC – VBAT Lockout Threshold Voltage ITERM Min C/10 Termination Current Threshold Typ Max Unit 3.4 V 100 mV PROG Pin Rising 1.25 V PROG Pin Falling 1.2 V VCC from Low to High 100 mV VCC from High to Low 30 mV 0.1 mA/mA 0.1 mA/mA RPROG = 10k (4) RPROG = 2k VPROG PROG Pin Voltage RPROG = 10k, Current Mode 0.9 1.03 1.1 V ICHRG CHRG Pin Weak Pull-Down Current VCHRG = 3V 15 µA VCHRG CHRG Pin Output Low Voltage ICHRG = 5mA 0.6 V ΔVRECHRG Recharge Battery Threshold Voltage VFLOAT - VRECHRG 100 mV TLIM Thermal Protection Temperature 120 °C tSS Soft-Start Time IBAT = 0 to 1000V/RPROG 100 µs tRECHARGE Recharge Comparator Filter Time VBAT High to Low 1 ms tTERM Termination Comparator Filter Time IBAT Falling Below ICHG/10 1000 µs IPROG PROG Pin Pull-Up Current 1 µA Note 1: Exceeding the absolute maximum rating may damage the device. Note 2: The device is not guaranteed to function outside its operating rating. Note 3: Supply current includes PROG pin current (approximately 100µA) but does not include any current delivered to the battery through the BAT pin (approximately 100mA). Note 4: ITERM is expressed as a fraction of measured full charge current with indicated PROG resistor. Pin Functions Pin Pin Function Description Pin P Positive Input Supply Voltage. Provides VCC power to the charger. VCC can range from 4.25V to 6.5V and should be Open-Drain Charge Status Output. When the battery is charging, the CHRG bypassed with at least a 1μF capacitor. Ground. GND Pin Function Description CHRG pin is 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. PROG Charge Current Program, Charge Current Monitor and Shutdown Pin. Charge Current Output. Provides BAT charge current to the battery and regulates the final float voltage to 4.2V. Revision 6/7/2007 Preliminary and all contents are subject to change without prior notice © Seaward Electronics Inc., 2007. • www.seawardinc.com • Page 3 Charge Current vs Supply Voltage Float Voltage vs Supply Voltage 600 4.230 RPROG=2k 4.225 4.220 TA=25℃ 4.210 4.205 4.200 4.195 VBAT=4V 300 TA=25℃ 200 100 4.190 4.5 5.0 5.5 VCC (V) 6.0 RPROG=10k 0 4.0 4.185 4.0 6.5 5.0 5.5 6.0 6.5 7.0 Float Voltage vs Temperature Trickle Charge Current vs Supply Voltage 4.215 60 4.210 RPROG=2k 50 V FLOAT (V) 4.205 40 ITR IKL (mA) 4.5 VCC (V) 70 VBAT=2.5V TA=25℃ 30 20 RPROG=10k 10 0 4.0 ONSET OF THERMAL REGULATION 400 IBAT (m A ) 4.215 V BAT (V) 500 RPROG=10k 4.200 4.195 4.190 4.185 4.5 5.0 5.5 VCC (V) 6.0 6.5 7.0 20 40 60 80 Temperature (℃) Revision 6/7/2007 Preliminary and all contents are subject to change without prior notice © Seaward Electronics Inc., 2007. • www.seawardinc.com • Page 4 100 120 Operation The SE9016 is a single cell lithium-ion battery current are calculated using the following equations: charger using a constant-current/constant-voltage R PROG = algorithm. It can deliver up to 800mA of charge 1100V 1100V , I CHG = , I CHG RPROG current (using a good thermal PCB layout) with a The charge current out of the BAT pin can be final float voltage accuracy of ±1%. The SE9016 determined at any time by monitoring the PROG pin includes an internal P-channel power MOSFET and voltage using the following equation: thermal regulation circuitry. No blocking diode or I BAT = external current sense resistor is required; thus, the VPROG • 1100 RPROG basic charger circuit requires only two external Charge Termination components. Furthermore, the SE9016 is capable A charge cycle is terminated when the charge current of operating from a USB power source. falls to 1/10th the programmed value after the final Normal Charge Cycle float voltage is reached. This condition is detected by A charge cycle begins when the voltage at the VCC using an internal, filtered comparator to monitor the pin rises above the UVLO threshold level and a 1% PROG pin. When the PROG pin voltage falls below program resistor is connected from the PROG pin to 100mV for longer than tTERM (typically 1ms), charging ground or when a battery is connected to the is terminated. The charge current is latched off and charger output. If the BAT pin is less than 2.8V, the the SE9016 enters standby mode, where the input charger enters trickle charge mode. In this mode, supply the SE9016 supplies approximately 1/10 the termination is disabled in trickle charging and thermal programmed charge current to bring the battery limiting modes). voltage up to a safe level for full current charging. When charging, transient loads on the BAT pin can When the BAT pin voltage rises above 2.8V, the cause the PROG pin to fall below 100mV for short charger enters constant-current mode, where the periods of time before the DC charge current has programmed charge current is supplied to the dropped to 1/10th the programmed value. The 1ms battery. When the BAT pin approaches the final filter time (tTERM) on the termination comparator float enters ensures that transient loads of this nature do not constant-voltage mode and the charge current result in premature charge cycle termination. Once begins to decrease. When the charge current drops the average charge current drops below 1/10th the to 1/10 of the programmed value, the charge cycle programmed value, the SE9016 terminates the ends. charge cycle and ceases to provide any current voltage (4.2V), the SE9016 current drops to 200mA. (Note: C/10 through the BAT pin. In this state, all loads on the Programming Charge Current BAT pin must be supplied by the battery. The charge current is programmed using a single The SE9016 constantly monitors the BAT pin voltage resistor from the PROG pin to ground. The battery in standby mode. If this voltage drops below the charge current is 1100 times the current out of the 4.05V recharge threshold (VRECHRG), another charge PROG pin. The program resistor and the charge cycle begins and current is once again supplied to the Revision 6/7/2007 Preliminary and all contents are subject to change without prior notice © Seaward Electronics Inc., 2007. • www.seawardinc.com • Page 5 battery. To manually restart a charge cycle when in Undervoltage Lockout (UVLO) standby mode, the input voltage must be removed An internal undervoltage lockout circuit monitors the and reapplied, or the charger must be shut down and input voltage and keeps the charger in shutdown restarted using the PROG pin. Figure 1 shows the mode until VCC rises above the undervoltage lockout state diagram of a typical charge cycle. threshold. The UVLO circuit has a built-in hysteresis of 200mV. Furthermore, to protect against reverse Charge Status Indicator (CHRG) current in the power MOSFET, the UVLO circuit The charge status output has three different states: keeps the charger in shutdown mode if VCC falls to strong pull-down (~10mA), weak pull-down (~20μA) within 30mV of the battery voltage. If the UVLO and high impedance. The strong pull-down state comparator is tripped, the charger will not come out of indicates that the SE9016 is in a charge cycle. Once shutdown mode until VCC rises 100mV above the the charge cycle has terminated, the pin state is battery voltage. determined by undervoltage lockout conditions. A weak pull-down indicates that VCC meets the UVLO conditions and the SE9016 is ready to charge. High impedance indicates that the SE9016 is in Power On undervoltage lockout mode: either VCC is less than VBAT<2.8V 100mV above the BAT pin voltage or insufficient voltage is applied to the VCC pin. PROG Reconnected Or UVLO Connection Stops Trickle Charge Mode 1/10 TH of Full Current Chrg LED: Strong Pull-Dn Thermal Limiting An internal thermal feedback loop reduces the VBAT>2.8V programmed charge current if the die temperature Shutdown Mode CC/CV Charge Mode ICC Drops to < 20μA Full Current attempts Chrg: Hi-Z In UVLO to rise above a preset value of approximately 120℃. This feature protects the WeakPull-Dn Otherwise Chrg LED: Strong Pull-Dn VPROG<100mV SE9016 from excessive temperature and allows the Standby Mode user to push the limits of the power handling capability of a given circuit board without risk of damaging the SE9016. The charge current can be set according to typical (not worst-case) VBAT>2.8V No Charge Current PROG Floated Or UVLO Connection Chrg LED: Weak Pull-Dn ambient 4.05V>VBAT>2.8V temperature with the assurance that the charger will automatically reduce the current in worst-case Figure1. State Diagram of a Typical Charge Cycle conditions. Revision 6/7/2007 Preliminary and all contents are subject to change without prior notice © Seaward Electronics Inc., 2007. • www.seawardinc.com • Page 6 Application Hints Power Dissipation Stability Considerations The constant-voltage mode feedback loop is stable without an output capacitor provided a battery is connected to the 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. 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 The conditions that cause the SE9016 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°C – PDθJA TA = 120°C – (VCC – VBAT) • IBAT • θJA PROG pin, the charger is stable with program resistor values as high as 20k. However, additional capacitance on this node reduces the maximum allowed program resistor. The pole frequency at the PROG pin should be kept above 100kHz. 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 VCC Bypass Capacitor the IC is from the die to the copper lead frame, Many types of capacitors can be used for input through the package leads, (especially the ground bypassing, however, caution must be exercised lead) to the PC board copper. The PC board copper when using multilayer ceramic capacitors. Because is the heat sink. The footprint copper pads should of the self-resonant and high Q characteristics of be as wide as possible and expand out to larger some types of ceramic capacitors, high voltage copper areas to spread and dissipate the heat to transients can be generated under some start-up the surrounding ambient. Other heat sources on the conditions, such as connecting the charger input to board, not related to the charger, must also be a live power source. Adding a 1.5Ω resistor in series considered when designing a PC board layout with a ceramic capacitor will minimize start-up because they will affect overall temperature rise and voltage transients. the maximum charge current. Revision 6/7/2007 Preliminary and all contents are subject to change without prior notice © Seaward Electronics Inc., 2007. • www.seawardinc.com • Page 7 OUTLINE DRAWING SOT-23-5L K B H D A F E C J DIMN A B C D E F H J K DIMENSIONS INCHES MM MIN MAX MIN MAX 0.110 0.059 0.036 0.014 0.0035 0.102 0.120 0.070 0.051 0.020 0.037 0.075 0.006 0.008 0.118 Contact Information Seaward Electronics Incorporated – China Room 1605, Building 1, International Pioneering Park, #1 Shangdi Xinxi Rd. Haidian District, Beijing 100085, China Tel: 86-10-8289-5700/01/05 Fax: 86-10-8289-5706 Email: [email protected] Seaward Electronics Corporation – Taiwan 2F, #181, Sec. 3, Min Quan East Rd. Taipei, Taiwan R.O.C Tel: 886-2-2712-0307 Fax: 886-2-2712-0191 Email: [email protected] Seaward Electronics Incorporated – North America 1512 Centre Pointe Dr. Milpitas, CA95035, USA Tel: 1-408-821-6600 Last Updated - 6/7/2007 Revision 6/7/2007 Preliminary and all contents are subject to change without prior notice © Seaward Electronics Inc., 2007. • www.seawardinc.com • Page 8 2.80 1.50 0.90 0.35 0.090 2.60 3.05 1.75 1.30 0.50 0.95 1.90 0.15 0.20 3.00