AAT3685IWP-4.2-1-T1

Lithium-Ion/Polymer Battery Charger General Description The AAT3685 BatteryManager™ is a highly integrated single cell lithium-ion/polymer battery charger IC designed to operate with USB port or line adapter inputs. It requires the minimum number of external components. The AAT3685 precisely regulates battery charge voltage and current for 4.2V lithium-ion/polymer battery cells. Regardless of the type of input power source (USB or adapter), the AAT3685 can be programmed for two separate constant current charge levels up to 1A. An optional Charge Reduction Loop is built in to allow users to charge the battery with available current from the charge supply, while keeping the port voltage regulated. Battery temperature and charge state are fully monitored for fault conditions. In the event of an over-voltage or over-temperature failure, the device will automatically shut down, thus protecting the charging device, control system, and the battery under charge. Status monitor output pins are provided to indicate the battery charge status by directly driving two external LEDs. A serial interface output is available to report any one of 14 various status states to a microcontroller. The AAT3685 is available in a Pb-free, thermallyenhanced, space-saving 12-pin 3x3mm TDFN package and is rated over the -40°C to +85°C temperature range. AAT3685 Features • • • BatteryManager™ • • • • • • • • • Adapter or USB Charger — Programmable up to 1A Max 4.0V to 5.5V Input Voltage Range High Level of Integration With Internal: — Charging Device — Reverse Blocking Diode — Current Sensing Automatic Recharge Sequencing Charge Reduction Loop Battery Temperature Monitoring Full Battery Charge Auto Turn-Off Over-Voltage Protection Emergency Thermal Protection Power On Reset and Soft Start Serial Interface Status Reporting 12-Pin 3x3mm TDFN Package Applications • • • • • • Cellular Telephones Digital Still Cameras Hand-Held PCs MP3 Players Personal Data Assistants (PDAs) Other Lithium-Ion/Polymer Battery-Powered Devices Typical Application Enable Adapter or USB Input Input Hi/Lo Select ADP/USB PWRSEL SETH RSETH RSETL SETL BAT TS C2 10μF EN CHR BATT+ AAT3685 GND BATT- DATA STAT1 STAT2 TEMP Battery Pack Serial Data 3685.2006.10.1.3 1 Lithium-Ion/Polymer Battery Charger Pin Descriptions Pin # 1 2 3 4 AAT3685 Name ADP/USB BAT GND CHR Type In In/Out Ground In/Out Function Line adapter or USB power supply input. Battery charging and sensing. Ground connection. Resistor divider to set USB voltage regulation for charge reduction mode. Leave this pin open for default 4.5V USB regulation point. Tie to ADP/USB pin to disable this function. Enable pin. Logic high enables the IC. Connect to 10kΩ NTC thermistor. Status report to microcontroller via serial interface, open-drain. Battery charge status indicator pin to drive an LED: active low, open-drain. Battery charge status indicator pin to drive an LED: active low, open-drain. When ADP/USB is present, use this pin to toggle between SETH and SETL charging levels. Connect resistor here to set charge current for low-current port. Connect resistor here to set charge current for high-current port. Exposed paddle (bottom); connect to GND directly beneath package. 5 6 7 8 9 10 11 12 EP EN TS DATA STAT2 STAT1 PWRSEL SETL SETH In In/Out In/Out Out Out In In/Out In/Out Pin Configuration TDFN33-12 (Top View) ADP/USB BAT GND CHR EN TS 1 2 3 4 5 6 12 11 10 9 8 7 SETH SETL PWRSEL STAT1 STAT2 DATA 2 3685.2006.10.1.3 Lithium-Ion/Polymer Battery Charger AAT3685 Feature Options Product AAT3685 AAT3685-1 AAT3685 Internal Pull-Up Resistor on EN Pin No Yes Can Leave TS Pin Open No Yes Absolute Maximum Ratings1 Symbol VP VP VN TJ TLEAD Description ADP/USB Input Voltage, VBAT Yes Preconditioning Test VMIN > VBAT No Yes Current Charging Mode Yes Low Current Conditioning Charge No Port Voltage Test VADP/USB < VADP/USB_CHR Yes Current Phase Test VEOC > VBAT No Charge Current Reduction Voltage Phase Test IBAT > ITERM No Charge Completed Yes Voltage Charging Mode 12 3685.2006.10.1.3 Lithium-Ion/Polymer Battery Charger Application Information USB System Power Charging The USB charge mode provides two programmable fast charge levels up to 1A for each, SETH and SETL. The SETH or SETL modes may be externally selected by the select pin (PWRSEL). When the PWRSEL pin is connected to a logic high level, the SETH level will be active. Conversely, when PWRSEL is pulled to a logic low level (ground), the SETL level will be used for fast charging. These two charge levels may be user programmed to any level between 50mA and 1A by selecting the appropriate resistor values for RSETH and RSETL. Refer to Table 1 for recommended RSETH and RSETL values for the desired input constant current charge levels. Charge Reduction In many instances, product system designers do not know the real properties of a potential port to be used to supply power to the battery charger. Typical powered USB ports commonly found on desktop and notebook PCs should supply up to 500mA. In the event a port being used to supply the charger is unable to provide the programmed fast charge current, or if the system under charge must also share supply current with other functions, the AAT3685 will automatically reduce USB fast charge current to maintain port integrity and protect the host system. The charge reduction system becomes active when the voltage on the input falls below the charge reduction threshold (VADP/USB_CHR), which is typically 4.5V. Regardless of which charge function is selected (SETH or SETL), the charge reduction system will reduce the fast charge current level in a linear fashion until the voltage sensed on the input recovers above the charge reduction threshold voltage. The charge reduction threshold (VADP/USB_CHR) may be externally set to a value lower than 4.5V by placing a resistor divider network between VADP/USB and ground with the center connected to the CHR pin. The charge reduction feature may be disabled by connecting a 10kΩ resistor from the CHR pin directly to the ADP/USB input pin. The following equation may be used to approximate a USB charge reduction threshold below 4.5V: AAT3685 R12 Eq. 1: VADP/USB_CHR = 2.0V ÷ R12 + R11 where R11/R12 2 PDATA N=1 N=2 N=3 Thermal Considerations The AAT3685 is packaged in a Pb-free, 3x3mm TDFN package which can provide up to 2.0W of power dissipation when it is properly bonded to a printed circuit board and has a maximum thermal resistance of 50°C/W. Many considerations should be taken into account when designing the printed circuit board layout, as well as the placement of the charger IC package in proximity to other heat generating devices in a given application design. The ambient temperature around the charger IC will also have an affect on the thermal limits of a battery charging application. The maximum limits that can be expected for a given ambient condition can be estimated by the following discussion. First, the maximum power dissipation for a given situation should be calculated: Eq. 4: PD = [(VIN - VBAT) · ICC + (VIN · IOP)] Where: PD = Total Power Dissipation by the Device VIN = Input Voltage Level, VADP/USB VBAT = Battery Voltage as Seen at the BAT Pin ICC IOP = Maximum Constant Fast Charge Current Programmed for the Application = Quiescent Current Consumed by the Charger IC for Normal Operation Next, the maximum operating ambient temperature for a given application can be estimated based on the thermal resistance of the 3x3mm TDFN package when sufficiently mounted to a PCB layout and the internal thermal loop temperature threshold. Eq. 5: TA = TJ - (θJA · PD) 18 3685.2006.10.1.3 Lithium-Ion/Polymer Battery Charger Where: TA TJ PD = Ambient Temperature in Degrees C = Maximum Device Junction Temperature Protected by the Thermal Limit Control = Total Power Dissipation by the Device AAT3685 Capacitor Selection Input Capacitor In general, it is good design practice to place a decoupling capacitor between the ADP/USB pin and ground. An input capacitor in the range of 1μF to 22μF is recommended. If the source supply is unregulated, it may be necessary to increase the capacitance to keep the input voltage above the under-voltage lockout threshold during device enable and when battery charging is initiated. If the AAT3685 input is to be used in a system with an external power supply source rather than a USB port VBUS, such as a typical AC-to-DC wall adapter, then a CIN capacitor in the range of 10μF should be used. A larger input capacitor in this application will minimize switching or power bounce effects when the power supply is "hot plugged" in. Likewise, a 10μF or greater input capacitor is recommended for the USB input to help buffer the effects of USB source power switching noise and input cable impedance. Output Capacitor The AAT3685 only requires a 1μF ceramic capacitor on the BAT pin to maintain circuit stability. This value should be increased to 10μF or more if the battery connection is made any distance from the charger output. If the AAT3685 is to be used in applications where the battery can be removed from the charger, such as in the case of desktop charging cradles, an output capacitor greater than 10μF may be required to prevent the device from cycling on and off when no battery is present. θJA = Package Thermal Resistance in °C/W Example: For an application where the fast charge current is set to 500mA, VUSB = 5.0V and the worst case battery voltage at 3.0V, what is the maximum ambient temperature at which the thermal limiting will become active? Given: VUSB = 5.0V VBAT = 3.0V ICC IOP TJ = 500mA = 0.75mA = 140°C θJA = 50°C/W Using Equation 4, calculate the device power dissipation for the stated condition: Eq. 6: PD = (5.0V - 3.0V)(500mA) + (5.0V · 0.75mA) = 1.00375W The maximum ambient temperature before the AAT3685 thermal limit protection will shut down charging can now be calculated using Equation 5: Eq. 7: TA = 140°C - (50°C/W · 1.00375W) Printed Circuit Board Layout Considerations For the best results, it is recommended to physically place the battery pack as close as possible to the AAT3685 BAT pin. To minimize voltage drops on the PCB, keep the high current carrying traces adequately wide. For maximum power dissipation of the AAT3685 3x3mm TDFN package, the metal substrate should be solder bonded to the board. It is also recommended to maximize the substrate contact to the PCB ground plane layer to further increase local heat dissipation. Refer to the AAT3685 evaluation board for a good layout example (see Figures 5 and 6). = 89.81°C Therefore, under the stated conditions for this worst case power dissipation example, the AAT3685 will suspend charging operations when the ambient operating temperature rises above 89.81°C. 3685.2006.10.1.3 19 Lithium-Ion/Polymer Battery Charger AAT3685 Evaluation Board Layout AAT3685 Figure 5: AAT3685 Evaluation Board Component Side Layout. Figure 6: AAT3685 Evaluation Board Solder Side Layout. 20 3685.2006.10.1.3 Lithium-Ion/Polymer Battery Charger AAT3685 Evaluation Board Schematic Diagram ON/OFF J1 Mini-B GND ID D+ DADP/USB 5 4 3 2 1 123 AAT3685 PWRSEL J2 123 HI LO C2 TB1 ADP/USB GND 1 2 RED GRN LED D2 LED D1 R9 1.5K 10μF R2 R3 Open Open 1 5 U1 AAT3685 PWRSEL STAT2 STAT1 DATA 10 8 9 7 11 12 R5 1.5K R6 1.5K ADP/USB EN BAT BAT TS GND TB2 1 2 3 2 DATA C1 10μF 4 CHR TS GND 3 SETL SETH 6 R8 8.06K R7 40.2K R4 10K R1 Open TDFN33-12 SW1 3685.2006.10.1.3 21 Lithium-Ion/Polymer Battery Charger AAT3685 Evaluation Board Bill of Materials (BOM) Quantity Description 1 1 1 1 2 1 1 2 1 3 1 1 1 1 AAT3685 Desig. Footprint PAD TBLOK2 TBLOK3 USB-MINI-B 0805 1206LED Manufacturer Mill-Max Phoenix Contact Phoenix Contact Part Number 6821-0-0001-00-00-08-0 277-1274-ND 277-1273-ND Test Pin DATA Connecting Terminal Block, USB,GND 2.54mm, 2 Pos Connecting Terminal Block, BAT, GND, TS 2.54mm, 3 Pos USB 2.0 Receptacle, 5 Pos USB Capacitor, Ceramic, 10μF 6.3V 10% X5R 0805 Typical Red LED, Super Bright Typical Green LED Header, 3-Pin Resistor, 10kΩ 1/16W 5% 0603 SMD Resistor, 1.5kΩ 1/16W 1% 0603 SMD Resistor, 40.2kΩ 1/16W 1% 0603 SMD Resistor, 8.06kΩ 1/16W 1% 0603 SMD Switch Tact 6mm SPST H = 5.0mm AAT3685 Lithium-Ion/ Polymer Battery Charger C1, C2 D1 D2 J1, J2 R4 R5, R6, R9 R7 R8 SW1 U1 Hirose Electronic H2959CT-ND Co. Ltd. MuRata 490-1717-1-ND CMD15-21SRC/TR8 CMD15-21VGC/TR8 6821-0-0001-00-00-08-0 P10KCFCT-ND P1.5KCGCT-ND P40.2KHTR-ND P8.06KHCT-ND CKN9012-ND AAT3685IWP Chicago Miniature Lamp 1206LED Chicago Miniature Lamp HEADER2MM-3 Sullins 0603 Panasonic/ECG 0603 0603 0603 SWITCH TDFN33-12 Panasonic/ECG Panasonic/ECG Panasonic/ECG ITT Industries/ C&K Div. AnalogicTech 22 22 3685.2006.10.1.3 Lithium-Ion/Polymer Battery Charger Ordering Information Package TDFN33-12 TDFN33-12 AAT3685 Marking1 RNXYY TMXYY Part Number (Tape and Reel)2 AAT3685IWP-4.2-T1 AAT3685IWP-4.2-1-T1 All AnalogicTech products are offered in Pb-free packaging. The term “Pb-free” means semiconductor products that are in compliance with current RoHS standards, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. For more information, please visit our website at http://www.analogictech.com/pbfree. Package Information Index Area (D/2 x E/2) Detail "B" 3.00 ± 0.05 2.40 ± 0.05 0.3 ± 0.10 0.16 0.375 ± 0.125 0.075 ± 0.075 0.1 REF Top View Bottom View Pin 1 Indicator (optional) 7.5° ± 7.5° + 0.05 0.8 -0.20 0.229 ± 0.051 0.05 ± 0.05 Option A: C0.30 (4x) max Chamfered corner Option B: R0.30 (4x) max Round corner Detail "B" Side View All dimensions in millimeters. 1. XYY = assembly and date code. 2. Sample stock is generally held on part numbers listed in BOLD. © Advanced Analogic Technologies, Inc. Detail "A" AnalogicTech cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in an AnalogicTech product. No circuit patent licenses, copyrights, mask work rights, or other intellectual property rights are implied. AnalogicTech 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. AnalogicTech warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with AnalogicTech’s standard warranty. Testing and other quality control techniques are utilized to the extent AnalogicTech deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed. AnalogicTech and the AnalogicTech logo are trademarks of Advanced Analogic Technologies Incorporated. All other brand and product names appearing in this document are registered trademarks or trademarks of their respective holders. Advanced Analogic Technologies, Inc. 830 E. Arques Avenue, Sunnyvale, CA 94085 Phone (408) 737-4600 Fax (408) 737-4611 3685.2006.10.1.3 0.23 ± 0.05 0.45 ± 0.05 Detail "A" 3.00 ± 0.05 1.70 ± 0.05 23