LM3622 LM3622 Lithium-Ion Battery Charger Controller Literature Number: SNVS043A LM3622 Lithium-Ion Battery Charger Controller General Description The LM3622 is a charge controller for Lithium-Ion batteries. This monolithic integrated circuit accurately controls an external pass transistor for precision Lithium-Ion battery charging. The LM3622 provides a constant voltage or constant current (CVCC) configuration that changes, as necessary, to optimally charge lithium-ion battery cells. Voltage charging versions (4.1V, 4.2V, 8.2V, and 8.4V) are available for one or two cell battery packs and for coke or graphite anode battery chemistry. The LM3622 accepts input voltages from 4.5V to 24V. Controller accuracy over temperature is 30mV/cell for A grade and 50mV/cell for the standard grade. No precision external resistors are required. Furthermore, the LM3622's proprietary output voltage sensing circuit drains less than 200nA from the battery when the input source is disconnected. The LM3622 circuitry includes functions for regulating the charge voltage with a temperature compensated bandgap reference and regulating the current with an external sense resistor. The internal bandgap insures excellent controller performance over the operating temperature and input supply range. The LM3622 can sink 15mA minimum at the EXT pin to drive the base of an external PNP pass transistor. It also has low-voltage battery threshold circuitry that removes this drive when the cell voltage drops below a preset limit. The LVSEL pin programs this threshold voltage to either 2.7V/cell or 2.15V/cell. The low-voltage detection, which is a user enabled feature, provides an output signal that can be used to enable a "wake up charge" source automatically to precondition a deeply discharged pack. The LM3622 is available in a standard 8-lead SOIC surface mount package. Features n Versions for charging of 1 cell (4.1V or 4.2V) or 2 cells (8.2V or 8.4V) n Versions for coke or graphite anode n Precision ( 30mV/cell) end-of-charge control n Wide input range: 4.5V-24V n Low battery drain leakage: 200nA n 15 mA available to drive low cost PNP Applications n Cellular phone cradle charger n PDA/Notebook cradle charger n Camcorder cradle charger Typical Application 10097401 (c) 2004 National Semiconductor Corporation DS100974 www.national.com LM3622 Lithium-Ion Battery Charger Controller February 2000 LM3622 Connection Diagram 8-Lead Surface Mount Package 10097402 Refer to the Ordering Information Table in this Datasheet for Specific Part Number See NS Package M08A Pin Description Pin No. Name I/O 1 LVSEL Input Low-voltage detection threshold Select. The threshold is 2.15V/cell when this pin is pulled low to GND and 2.70V/cell when it is pulled up to VCC. The battery voltage is sensed between CEL and CS pins. 2 LVENB Input Low-voltage detection Enable. The low-voltage detection is enabled when this pin is pulled Low to GND. Pulling this pin HIGH to VCC disables the low-voltage detection. 3 LV Output Output of the low-voltage detection. This pin is a NPN open-collector output that goes to low impedance state when LVENB is pulled LOW and the battery voltage is below the threshold set by LVSEL. LV stays in HIGH impedance state at any battery voltage when LVENB is pulled HIGH to VCC. LV can be used for turning on a low current source to recondition a deeply depleted battery. 4 GND Ground IC common. 5 CS Input Input for battery charge current and battery negative-terminal voltage sensing. Battery charging current is sensed through an external resistor, RCS, connected between the battery's negative terminal and GND. The maximum charge current is regulated to a value of 100mV/RCS. Battery positive-terminal voltage sensing. 6 CEL Input 7 EXT Output 8 VCC Power Supply www.national.com Description Output of the controller for driving a PNP transistor or P-MOSFET. The controller modulates the current sinking into this pin to control the regulation of either the charge current or the battery voltage. IC power supply 2 LM3622 Ordering Information Voltage Grade Accuracy 30mV 30mV 50mV 50mV 30mV 30mV 50mV 50mV 60mV 60mV 100mV 100mV 60mV 60mV 100mV 100mV 4.1V A 4.1V A 4.1V Standard 4.1V Standard 4.2V A 4.2V A 4.2V Standard 4.2V Standard 8.2V A 8.2V A 8.2V Standard 8.2V Standard 8.4V A 8.4V A 8.4V Standard 8.4V Standard Order Information LM3622AM-4.1 LM3622AMX-4.1 LM3622M-4.1 Supplied As 95 unit increments in rail 2500 unit increments in tape and reel 95 unit increments in rail LM3622MX-4.1 2500 unit increments in tape and reel LM3622AM-4.2 95 unit increments in rail LM3622AMX-4.2 LM3622M-4.2 2500 unit increments in tape and reel 95 unit increments in rail LM3622MX-4.2 2500 unit increments in tape and reel LM3622AM-8.2 95 unit increments in rail LM3622AMX-8.2 LM3622M-8.2 2500 unit increments in tape and reel 95 unit increments in rail LM3622MX-8.2 2500 unit increments in tape and reel LM3622AM-8.4 95 unit increments in rail LM3622AMX-8.4 LM3622M-8.4 LM3622MX-8.4 3 2500 unit increments in tape and reel 95 unit increments in rail 2500 unit increments in tape and reel www.national.com LM3622 Absolute Maximum Ratings (Note 1) Power Dissipation (TA = 25C) (Note 4) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Max. Package Dissipation Supply Voltage (VCC) -0.3 to 24V LV -0.3 to 24V EXT (Note 2) -0.3 to 24V LVSEL -0.3 to 24V LVENB -0.3 to 24V ESD Susceptibility (Note 3) Storage Temperature Operating Ratings (Note 1) Supply Voltage (VCC) 4.5V to 24V Ambient Temperature Range -20C to 70C Junction Temperature Range -20C to 85C Thermal Resistance, JA 2500V SOIC-8 -40C to +125C Lead Temp. Soldering Vapor Phase (60 sec.) Infrared (15 sec.) 350mW 170C/W 215C 220C Electrical Characteristics LM3622-XX Unless otherwise specified VCC = 5V/Cell TA =TJ = 25C. Limits with standard typeface apply for TJ = 25C, and limits in boldface type apply over the indicated temperature range. Symbol Parameter Conditions VCC Operating power supply range ICC Quiescent Current TJ = 0C to +70C VCC = 4.5V/cell (Note 5) VCEL Regulation Voltage LM3622A-4.1 LM3622A-8.2 LM3622A-4.2 LM3622A-8.4 LM3622-4.1 LM3622-8.2 LM3622-4.2 LM3622-8.4 Min Typ 4.5 Max 24.0 210 4.070 8.140 4.170 8.340 4.050 8.100 4.150 8.300 4.100 8.200 4.200 8.400 4.100 8.200 4.200 8.400 Units V A 4.130 8.260 4.230 8.460 4.150 8.300 4.250 8.500 V V V V V V V 110 mV Long Term Stability (Note 6) VCS Current limit threshold at CS pin VCEL = 4V for LM3622-4.X VCEL = 8V for LM3622-8.X 0.02 ICEL Current in CEL pin VCC Supply connected LVth Low voltage detect threshold (between pins CS and GND) LVENB = 0V and LVSEL = 0V 2.00 2.15 2.30 V/Cell LVENB = 0V and LVSEL = VCC 2.55 2.70 2.85 V/Cell IEXT EXT pin output sink current VEXT = 4V for LM3622-4.X VEXT = 8V for LM3622-8.X 15 25 mA IIN1 LVSEL input current LVSEL = 5V, LM3622-4.X LVSEL = 10V, LM3622-8.X 20 50 A IIN2 LVENB input current LVENB = 5V, LM3622-4.X LVENB = 10V, LM3622-8.X 20 50 A ILV LV pin leakage current LV = 5V/Cell VLV LV pin saturation voltage ISINK = 1mA TJ = -20C to 85C 90 100 % 25 VCC Supply Open A 200 0.25 nA 250 nA 0.40 V Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is intended to be functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics. Note 2: VEXT is not allowed to exceed (VCC+ 0.3V) or damage to the device may occur. Note 3: Rating is for the human body model, a 100 pF capacitor discharged through a 1.5k resistor into each pin. Note 4: The maximum power dissipation must be de-rated at elevated temperatures and is limited by TJMAX (maximum junction temperature), JA (junction-toambient thermal resistance) and TA (ambient temperature). The maximum power dissipation at any temperature is: PDissMAX = (TJMAX - TA) / JA up to the value listed in the Absolute Maximum Ratings. Note 5: Limits reflect initial accuracy. www.national.com 4 LM3622 Electrical Characteristics (Continued) Note 6: TJ = 85C, 1000 hours. Activation energy of 0.78eV used. Typical Performance Characteristics Unless otherwise specified, TA = 25C. Current Sense Voltage Regulation Vs VCC Output Voltage Regulation Vs VCC 10097405 Output Drive Current Vs VCC Current Sense Voltage Regulation Vs Temperature 10097404 10097408 Output Drive Current Vs VCC 10097406 10097407 5 Quiescent Current Vs VCC 10097403 www.national.com LM3622 Functional Description 10097411 FIGURE 1. LM3622 Simplified Block Diagram the power down switch will disconnect the resistor divider from the CS pin, preventing the battery from discharging through the CEL pin. The simplified LM3622 block diagram in Figure 1 gives a general idea of the circuit operation. The controller integrates the reference, feedback and drive functions on-chip to control a linear, lithium-ion battery charger in constant voltage and constant current (CVCC) charge operation. The regulated output voltage is sensed between CEL and CS, and the battery charge current is sensed across a current-sense resistor between CS and GND. The EXT pin is designed for driving a series pass element, which can be a PNP transistor or a P-MOSFET. Tying the LVENB pin to ground enables the controller's lowvoltage detection circuit. When the low-voltage detection circuit is enabled and a battery voltage below a preset threshold is detected, the LM3622 will drive the LV pin low and shut off the current flowing into the EXT pin to suspend the CVCC charge process. The low-voltage threshold is user selectable to be either 2.15V/cell or 2.7V/cell by pulling the LVSEL pin to GND or VCC respectively. The LV pin is a NPN open collector output that can be used to turn on a low current source to wake up charge a deeply depleted battery. When the low-voltage detection is disabled (LVENB pulled up to VCC), the LM3622 always starts the charge cycle in constant current mode at any battery voltage below the controller's regulation level, and maintains the LV pin at a highimpedance state. EXT PIN The EXT pin is internally pulled up to VCC via a 20A current source making it possible to eliminate the external baseemitter resistor when driving a PNP transistor, or the gatesource resistor when driving a P-MOSFET. However, the voltage applied to EXT is not allowed to be higher than (VCC + 0.3V), otherwise the reverse current from EXT pin to VCC pin may cause damage to the device. LV PIN CURRENT RATING The LV pin is a low power, NPN open collector output that is rated to sink 10mA maximum. Therefore, the value of the pull up resistor should be chosen high enough to limit the current to be less than 10mA. CS PIN In normal operation, the current limit threshold voltage for the CS pin is 100mV typical. In case of a fault condition, the voltage to this pin should be limited to below 5V. Application Information CEL PIN CURRENT DRAIN The LM3622 has an internal power down switch in series with the on-chip resistor divider that is used for sensing the battery voltage. In the event that the VCC supply is removed, www.national.com 6 LM3622 Typical Application 10097413 FIGURE 2. Low Dropout, Constant Current/Constant Voltage Li-ion Battery Charger The low dropout linear charger shown in Figure 2 provides constant current and constant voltage charging of 1-cell lithium-ion battery packs. J1 and J2 are used for selecting the operation of the low-voltage detection. The LM3622 initializes the charge cycle based on the battery voltage and the enable status of the low-voltage detection. When the low-voltage detection is disabled, the LM3622 starts the charge cycle constant current mode if the battery voltage is below the controller's regulation level. In constant current mode, the LM3622 modulates the base drive of Q2 to regulate a constant 100mV across the current sense resistor R1, thus generating charge current of I-charge = 0.1V/R1 which is equal to 0.5A in this case. Once the battery voltage reaches the target regulation level set by the LM3622, Q2 is controlled to regulate the voltage across the battery, and the constant voltage mode of the charging cycle starts. Once the charger is in the constant voltage mode, the charger maintains a regulated voltage across the battery and the charging current is dependent on the state of the charge of the battery. As the cell approaches a fully charged condition, the charge current falls to a very low value. When the low-voltage detection is enabled and the initial battery voltage is below the low-voltage threshold, the LM3622 turns Q2 off and forces the LV pin low to drive Q1 on to start a wake up charge phase. Q1 in conjunction with R2 provides a low current source to recondition the battery. During the wake up charge mode, Q1 is driven into saturation and the wake up charge current is programmed by R2, I-charge (wake) = (VIN - VCE1 - VD1 - LVth)/R2 where VIN is the input supply voltage, VCE1 is the collectoremitter on state voltage of Q1, VD1 is the diode forward voltage of D1, and LVth is the low-voltage threshold level set by switch J2. Once the battery voltage reaches the low-voltage threshold, the LV pin transitions to a high-impedance state to end the wake up charge phase, and the EXT pin resumes the base drive of Q2 to start the constant current mode. The charging cycle is completed in constant voltage mode when the battery is fully charged. Figure 3 shows the timing diagram of the charge cycle with the low-voltage detection enabled. D1 is a general-purpose silicon diode used for isolating the battery from the charger circuitry that could discharge the battery when the input source is removed. Changing D1 to a Schottky diode will reduce the overall dropout voltage of the circuit, but the penalty is higher leakage current associated with Schottky diodes. 7 www.national.com LM3622 Timing Diagram 10097412 FIGURE 3. Typical Charge Cycle with Low-Voltage Detection Enabled. www.national.com 8 LM3622 Lithium-Ion Battery Charger Controller Physical Dimensions inches (millimeters) unless otherwise noted SOIC-8 Package 8-Lead Small-Outline Package (M8) For Ordering, Refer to Ordering Information Table NS Package Number M08A National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications. For the most current product information visit us at www.national.com. LIFE SUPPORT POLICY NATIONAL'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. BANNED SUBSTANCE COMPLIANCE National Semiconductor certifies that the products and packing materials meet the provisions of the Customer Products Stewardship Specification (CSP-9-111C2) and the Banned Substances and Materials of Interest Specification (CSP-9-111S2) and contain no ``Banned Substances'' as defined in CSP-9-111S2. National Semiconductor Americas Customer Support Center Email: new.feedback@nsc.com Tel: 1-800-272-9959 www.national.com National Semiconductor Europe Customer Support Center Fax: +49 (0) 180-530 85 86 Email: europe.support@nsc.com Deutsch Tel: +49 (0) 69 9508 6208 English Tel: +44 (0) 870 24 0 2171 Francais Tel: +33 (0) 1 41 91 8790 National Semiconductor Asia Pacific Customer Support Center Email: ap.support@nsc.com National Semiconductor Japan Customer Support Center Fax: 81-3-5639-7507 Email: jpn.feedback@nsc.com Tel: 81-3-5639-7560 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI's terms and conditions of sale supplied at the time of order acknowledgment. TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI's standard warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where mandated by government requirements, testing of all parameters of each product is not necessarily performed. TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and applications using TI components. To minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards. TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information published by TI regarding third-party products or services does not constitute a license from TI to use such products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI. Reproduction of TI information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for such altered documentation. Information of third parties may be subject to additional restrictions. Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements. TI products are not authorized for use in safety-critical applications (such as life support) where a failure of the TI product would reasonably be expected to cause severe personal injury or death, unless officers of the parties have executed an agreement specifically governing such use. Buyers represent that they have all necessary expertise in the safety and regulatory ramifications of their applications, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any use of TI products in such safety-critical applications, notwithstanding any applications-related information or support that may be provided by TI. Further, Buyers must fully indemnify TI and its representatives against any damages arising out of the use of TI products in such safety-critical applications. TI products are neither designed nor intended for use in military/aerospace applications or environments unless the TI products are specifically designated by TI as military-grade or "enhanced plastic." Only products designated by TI as military-grade meet military specifications. Buyers acknowledge and agree that any such use of TI products which TI has not designated as military-grade is solely at the Buyer's risk, and that they are solely responsible for compliance with all legal and regulatory requirements in connection with such use. TI products are neither designed nor intended for use in automotive applications or environments unless the specific TI products are designated by TI as compliant with ISO/TS 16949 requirements. Buyers acknowledge and agree that, if they use any non-designated products in automotive applications, TI will not be responsible for any failure to meet such requirements. Following are URLs where you can obtain information on other Texas Instruments products and application solutions: Products Applications Audio www.ti.com/audio Communications and Telecom www.ti.com/communications Amplifiers amplifier.ti.com Computers and Peripherals www.ti.com/computers Data Converters dataconverter.ti.com Consumer Electronics www.ti.com/consumer-apps DLP(R) Products www.dlp.com Energy and Lighting www.ti.com/energy DSP dsp.ti.com Industrial www.ti.com/industrial Clocks and Timers www.ti.com/clocks Medical www.ti.com/medical Interface interface.ti.com Security www.ti.com/security Logic logic.ti.com Space, Avionics and Defense www.ti.com/space-avionics-defense Power Mgmt power.ti.com Transportation and Automotive www.ti.com/automotive Microcontrollers microcontroller.ti.com Video and Imaging RFID www.ti-rfid.com OMAP Mobile Processors www.ti.com/omap Wireless Connectivity www.ti.com/wirelessconnectivity TI E2E Community Home Page www.ti.com/video e2e.ti.com Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265 Copyright (c) 2011, Texas Instruments Incorporated