Li-ion/Li Polymer Battery Charger

® ISL6297 Data Sheet March 20, 2007 FN9215.1 Li-ion/Li Polymer Battery Charger The ISL6297 is a Dual-Mode Lithium Ion battery charger optimized for cellular phone travel charger applications. It uses Intersil’s patent-pending dual-mode charge technology to minimize the heat normally generated in a linear charger. By minimizing the heat generation, the ISL6297 can be placed inside the connector of the travel charger to completely remove the influence of the adapter cable on the charging performance. The ISL6297 is an enhancement of the original ISL6292B. New features include improved accuracy, pre-charge circuit verification, and enhanced LED indicator function. Working with a current-limited AC/DC converter, the dualmode charger charges a Li-ion battery with the same current profile as a traditional linear charger. The constant charge current is determined by the current limit of the AC/DC converter. The constant output voltage is fixed at 4.2V. When the battery voltage is below 2.8V, the charger preconditions the battery with a low trickle-charge current. The charge status is indicated by a bi-color LED. A safety timer prevents charging a dead battery for an excessively long period. The ISL6297 also features THERMAGUARD™, a thermal foldback function that automatically reduces the charge current when the internal die temperature exceeds a +100°C limit to prevent further temperature rise. This function removes the concern of thermal failure in the targeted space-limited applications. An ambient temperature monitoring circuit allows users to set two separate temperature limit levels, for charge and non-charge conditions. The thermally-enhanced QFN package further improves the thermal performance of the ISL6297 in spacelimited applications. Features • Complete Charger for Single-Cell Li-ion Batteries • Integrated Pass Element and Current Sensor • No External Blocking Diode Required • Very Low Thermal Dual-Mode Operation • 0.7% Voltage Accuracy with Remote Sense • Pre-charge circuit verification with LED status indication • Drives a bi-color LED • Programmable Safety Timer • Programmable Current Limit up to 1.5A • Programmable End-of-Charge Current • THERMAGUARD™ Charge Current Thermal Foldback • NTC Thermistor Interface for Battery Temperature Monitor • Two-Level Ambient Temperature Setting • Guaranteed to Operate at 2.65V After Start-Up • Ambient Temperature Range: -20°C to +70°C • Thermally-Enhanced QFN Packages • QFN Package: - Compliant to JEDEC PUB95 MO-220 QFN - Quad Flat No Leads - Package Outline - Near Chip Scale Package footprint, which improves PCB efficiency and has a thinner profile • Pb-Free Plus Anneal Available (RoHS Compliant) Applications • PDAs, Cell Phones and Smart Phones • Portable Instruments, MP3 Players • Medical Handhelds Pinout ISL6297 (16 LD QFN) TOP VIEW BAT BAT VIN VIN • Self-Charging Battery Packs • Stand-Alone Chargers Ordering Information PART NUMBER 12 VSEN 11 TEMP 10 IMIN 9 IREF 16 VIN GRN RED TIME 1 2 3 4 5 GND 15 14 13 PART TEMP. MARKING RANGE (°C) ISL 6297CR 62 97CRZ -20 to +70 -20 to +70 PACKAGE PKG. DWG. # ISL6297CR* ISL6297CRZ* (Note) 16 Ld 4x4 QFN L16.4x4 16 Ld 4x4 QFN L16.4x4 (Pb-free) Add “-T” suffix for tape and reel. NOTE: Intersil Pb-free plus anneal products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin plate termination finish, which are RoHS compliant and compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020. 6 DT 7 EN 8 V2P9 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Thermaguard is a trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2005-2006. All Rights Reserved All other trademarks mentioned are the property of their respective owners. ISL6297 Absolute Maximum Ratings Supply Voltage (VIN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to 7V All Other Pins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to 5.5V Thermal Information Thermal Resistance (Notes 1, 2) θJA (°C/W) θJC (°C/W) 4x4 QFN Package . . . . . . . . . . . . . . . . 41 4 Junction Temperature Range . . . . . . . . . . . . . . . . .-55°C to +150°C Operating Temperature Range . . . . . . . . . . . . . . . . .-40°C to +85°C Storage Temperature Range . . . . . . . . . . . . . . . . . .-65°C to +150°C Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . +300°C Recommended Operating Conditions Ambient Temperature Range . . . . . . . . . . . . . . . . . . .-20°C to +70°C Supply Voltage, VIN . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3V to 6.5V Maximum Pin Voltage (Except VIN). . . . . . . . . . . . . . . . . . . . . 5.25V CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. +150°C max junction temperature is intended for short periods of time. Constantly operated at +150°C may shorten the life of the part. NOTES: 1. θJA is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach” features. See Tech Brief TB379. 2. θJC, “case temperature” location is at the center of the exposed metal pad on the package underside. See Tech Brief TB379. Electrical Specifications PARAMETER Typical values are tested at VIN = 5V and +25°C ambient temperature. Maximum and minimum values are guaranteed over recommended operating conditions, unless otherwise noted. SYMBOL TEST CONDITIONS MIN TYP MAX UNITS POWER-ON RESET, OVER VOLTAGE PROTECTION, PRE-REGULATOR Rising VIN Threshold Falling VIN Threshold 2.9V Reference Output Voltage 2.9V Reference Output Current VIN-BAT Comparator Offset STANDBY CURRENT VBAT Pin Sink Current VIN Pin Supply Current VIN Pin Supply Current Charger Reverse Current VOLTAGE REGULATION Output Voltage Dropout Voltage CHARGE CURRENT Charge/Protection Current Trickle Charge Current End-of-Charge Current CHARGE VOLTAGE THRESHOLDS Short-Circuit Threshold Trickle Charge Threshold - Rising Trickle Charge Threshold - Falling Recharge Threshold - Falling Difference from Final Battery Voltage Open Circuit Test Threshold- Rising VOCR VSC VMIN VMIN VRECHRG 0.9 2.7 2.6 3.90 1.0 2.9 2.7 4.00 -210 4.4 1.1 3.2 3.0 4.08 V V V V mV V ICHARGE ITRICKLE RIREF = 80kΩ, VBAT = 3.7V, VIN = 5V RIREF = 80kΩ, VBAT = 2.0V, VIN = 5V RIMIN = 133kΩ 900 85 56 1000 110 63 1100 135 70 mA mA mA VCH VBAT = 3.7V, ICHARGE = 0.65A 4.17 4.20 250 4.23 300 V mV ISTANDBY IVIN1 IVIN2 VIN floating or EN pin is floating BAT Pin floating, EN = LOW BAT Pin floating, EN = HIGH VIN = 4.3V, VSEN = BAT= 4.5V, EN = HIGH 1.0 0.5 3.0 1.5 1.0 6.0 μA mA mA μA V2P9 ILOAD = 2mA 2.9 2.3 30 3.4 2.4 2.9 4.0 2.65 30 V V V mA mV 2 FN9215.1 March 20, 2007 ISL6297 Electrical Specifications PARAMETER BATTERY TEMPERATURE MONITORING Low Temperature Threshold Low Temperature Hysteresis High Temperature Threshold High Temperature Hysteresis DT Pin MOSFET On Resistance Charge Current Foldback Threshold (Note 4) Current Foldback Gain (Note 5) OSCILLATOR Oscillation Period LOGIC INPUT AND OUTPUT EN Input Low EN Pin External Pull Down to Disable LED Sink Current (RED, GRN) LED Leakage Current NOTES: 3. The actual current may be lower due to the thermal foldback. 4. Guaranteed by design and characterization to be typically +100°C ±15%. 5. Guaranteed by design and characterization. Pin Voltage = 1.0V 5 10 0.8 50 1 V kΩ mA μA TOSC CTIME = 15nF 2.7 3.0 3.3 ms RDT TFOLD GFOLD VTMAX V2P9 = 2.88V VTMIN V2P9 = 2.88V 1.94 135 .704 160 2.0 167 .718 185 25 100 100 2.06 199 .732 200 V mV V mV Ω °C mA/°C Typical values are tested at VIN = 5V and +25°C ambient temperature. Maximum and minimum values are guaranteed over recommended operating conditions, unless otherwise noted. (Continued) SYMBOL TEST CONDITIONS MIN TYP MAX UNITS 3 FN9215.1 March 20, 2007 ISL6297 Pin Description PIN # 1, 15, 16 2 3 4 5 6 7 8 PIN NAME VIN GRN RED TIME GND DT EN V2P9 DESCRIPTION VIN is the input power source. It is recommended to have a 1Ω resistor in series with the input decoupling capacitor to prevent an over-shoot voltage when the input cable is plugged in. Open-drain LED drive pin. This pin sinks a constant-current 10mA to drive a green LED in a bi-color LED pack. Open-drain LED drive pin. This pin sinks a constant-current 10mA to drive a red LED in a bi-color LED pack. Timer Programming Input. The TIME pin determines the oscillation period by connecting a timing capacitor between this pin and GND. The oscillator provides a time reference for the charger. GND is the connection to system ground. Delta Temperature Setting Input. This pin sets the temperature difference before and after the charging starts. This pin can also be used as an indication whether or not the charger is charging. Enable Input. Connect EN LOW to enable the charger. Pull it HIGH or leave it floating to disable the charger. This pin is pulled up to 2.9V when left floating. Untrimmed 2.9V voltage output. This pin outputs a 2.9V voltage source when the input voltage is above POR threshold, independent on the EN pin input. The V2P9 output is used to power the LEDs, the NTC circuit, or for other functions. The maximum output current is 30mA. This output can also be used as an indication for adapter presence. This is the programming input for the constant charging current in a linear charger. In the typical application of a dual-mode charger, the IREF pin programs t