DATA SHEET AAT2557 500mA Battery Charger and 300mA LDO Regulator for Portable Systems General Description Features The AAT2557 is a fully integrated 500mA battery charger and a 300mA low dropout (LDO) linear regulator. The input voltage range is 4V to 6.5V for the battery charger and 2.7V to 5.5V for the linear regulator, making it ideal for applications operating with single-cell lithium-ion/ polymer batteries. • Battery Charger: ▪ Input Voltage Range: 4V to 6.5V ▪ Programmable Charging Current up to 500mA ▪ Highly Integrated With • Charging Device • Reverse Blocking Diode • Linear Regulator: ▪ 300mA Output Current ▪ Low Dropout: 400mV at 300mA ▪ Fast Line and Load Transient Response ▪ High Accuracy: ±1.5% ▪ 70µA Quiescent Current • Short-Circuit, Over-Temperature, and Current Limit Protection • TSOPJW-14 Package • -40°C to +85°C Temperature Range The battery charger is a complete constant current/constant voltage linear charger. It offers an integrated pass device, reverse blocking protection, high accuracy current and voltage regulation, charge status, and charge termination. The charging current is programmable via external resistor from 15mA to 500mA. In addition to these standard features, the device offers over-voltage, current limit, and thermal protection. The linear regulator is designed for fast transient response and good power supply ripple rejection. Capable of up to 300mA load current, it includes shortcircuit protection and thermal shutdown. Applications • • • • • • The AAT2557 is available in a Pb-free, thermallyenhanced TSOPJW-14 package and is rated over the -40°C to +85°C temperature range. Bluetooth™ Headsets Cellular and DECT Phones Handheld Instruments MP3 and Portable Music Players PDAs and Handheld Computers Portable Media Players Typical Application Adapter/USB Input ADP INLDO STAT C INLDO EN_BAT LDO Enable EN_LDO AAT2557 VOUTLDO BATT+ BAT C BAT OUTLDO C OUTLDO ISET BYP C BYP GND System Charger Enable BATTRSET Battery Pack Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202178A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 24, 2012 1 DATA SHEET AAT2557 500mA Battery Charger and 300mA LDO Regulator for Portable Systems Pin Descriptions Pin # Symbol 1 EN_LDO 2, 8, 12, 13, 14 GND 3 BYP 4 EN_BAT 5 ISET 6 7 9 10 11 BAT ADP STAT OUTLDO INLDO Function Enable pin for the linear regulator. When connected to logic low, the regulator is disabled and consumes less than 1µA of current. When connected to logic high, it resumes normal operation. Ground. Low noise bypass pin. Connect a 10nF capacitor between this pin and ground to improve AC ripple rejection and reduce noise. Enable pin for the battery charger. When connected to logic low, the battery charger is disabled and consumes less than 1µA of current. When connected to logic high, the charger resumes normal operation. Charge current set point. Connect a resistor from this pin to ground. Refer to typical characteristics curves for resistor selection. Battery charging and sensing. Input for USB/adapter charger. Charge status input. Open drain status output. Linear regulator output. Connect a 2.2µF capacitor from this pin to ground. Linear regulator input voltage. Connect a 1µF or greater capacitor from this pin to ground. Pin Configuration TSOPJW-14 (Top View) EN_LDO GND BYP EN_BAT ISET BAT ADP 2 1 14 2 13 3 12 4 11 5 10 6 9 7 8 GND GND GND INLDO OUTLDO STAT GND Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202178A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 24, 2012 DATA SHEET AAT2557 500mA Battery Charger and 300mA LDO Regulator for Portable Systems Absolute Maximum Ratings1 Symbol VINLDO VADP VEN VX VBYP TJ TA TLEAD Description Input Voltage to GND Adapter Voltage to GND EN_LDO, EN_BAT Voltage to GND BAT, ISET, STAT Voltage to GND BYP Voltage to GND Junction Temperature Range Operating Temperature Range Maximum Soldering Temperature (at leads, 10 sec) Value Units 6.0 -0.3 to 7.5 -0.3 to 6.0 -0.3 to VADP + 0.3 -0.3 to VINLDO + 0.3 -40 to 150 -40 to 85 300 V V V V V °C °C °C Value Units 625 160 mW °C/W Thermal Information Symbol PD qJA Description Maximum Power Dissipation Thermal Resistance2 1. Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at conditions other than the operating conditions specified is not implied. Only one Absolute Maximum Rating should be applied at any one time. 2. Mounted on an FR4 board. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202178A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 24, 2012 3 DATA SHEET AAT2557 500mA Battery Charger and 300mA LDO Regulator for Portable Systems Electrical Characteristics1 VINLDO = VOUTLDO(NOM) + 1V for VOUTLDO options greater than 1.5V. IOUTLDO = 1mA, COUTLDO = 2.2µF, CINLDO = 1µF, CBYP = 10nF, TA = -40°C to +85°C, unless otherwise noted. Typical values are TA = 25°C. Symbol Description Conditions Min Typ Max Units -1.5 1.5 % -2.5 2.5 VOUTLDO + VDOLDO2 5.5 V 600 mV Linear Regulator VOUTLDO Output Voltage Tolerance VINLDO Input Voltage VDOLDO DVOUT/ VOUTLDO*DVINLDO Dropout Voltage 3 Line Regulation DVOUTLDO(Line) Dynamic Line Regulation DVOUTLDO(Load) Dynamic Load Regulation IOUTLDO ISC IQLDO ISHDN Output Current Short-Circuit Current Quiescent Current Shutdown Current PSRR Power Supply Rejection Ratio TSD THYS eN TC TEN_LDO_DLY VEN_LDO(L) VEN_LDO(H) IEN_LDO Over-Temperature Shutdown Threshold Over-Temperature Shutdown Hysteresis Output Noise Output Voltage Temperature Coefficient LDO Enable Time Delay LDO Enable Threshold Low LDO Enable Threshold High LDO Enable Input Current IOUTLDO = 1mA to 300mA TA = 25°C TA = -40°C to +85°C IOUTLDO = 300mA 400 VINLDO = VOUTLDO + 1 to 5.0V 0.09 %/V 2.5 mV 60 mV 600 70 mA mA µA µA IOUTLDO = 300mA, VINLDO = VOUTLDO + 1 to VOUTLDO + 2, TR/ TF = 2µs IOUTLDO = 1mA to 300mA, TR <5µs VOUTLDO > 1.2V VOUTLDO < 0.4V VINLDO = 5V; VEN_LDO = VIN VINLDO = 5V; VEN_LDO = 0V 1kHz IOUTLDO =10mA 10kHz 1MHz 300 125 1.0 65 45 43 145 12 50 22 15 BYP Open dB 0.6 1.5 VEN_LDO = 5.5V 1.0 °C °C µVRMS ppm/°C µs V V µA 1. The AAT2557 is guaranteed to meet performance specifications over the -40°C to +85°C operating temperature range and is assured by design, characterization, and correlation with statistical process controls. 2.VDO is defined as VIN - VOUT when VOUT is 98% of nominal. 3. For VOUT < 2.3V, VDO = 2.5V - VOUT. 4 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202178A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 24, 2012 DATA SHEET AAT2557 500mA Battery Charger and 300mA LDO Regulator for Portable Systems Electrical Characteristics1 VADP = 5V; TA = -40°C to +85°C, unless otherwise noted. Typical values are TA = 25°C. Symbol Description Battery Charger Operation VADP Adapter Voltage Range Under-Voltage Lockout (UVLO) VUVLO UVLO Hysteresis IOP Operating Current ISHUTDOWN Shutdown Current ILEAKAGE Reverse Leakage Current from BAT Pin Voltage Regulation VCO(REG) Output Charge Voltage Regulation DVCH/VCH Output Charge Voltage Tolerance VMIN Preconditioning Voltage Threshold VRCH Battery Recharge Voltage Threshold Current Regulation ICH_CC Charge Current Programmable Range DICH_CC/ICH_CC Charge Current Regulation Tolerance VISET ISET Pin Voltage KI_A Current Set Factor: ICH/ISET Charging Devices RDS(ON) Charging Transistor On Resistance Logic Control/Protection VEN_BAT(H) Battery Charger Enable Threshold High VEN_BAT(L) Battery Charger Enable Threshold Low VSTAT STAT Pin Output Low Voltage ISTAT STAT Pin Current Sink Capability VOVP Battery Over-Voltage Protection Threshold ICH_TKL/ICH_CC Preconditioning Charge Current ICH_TERM/ICH_CC Charge Termination Current Conditions Rising Edge Min Typ 4.0 3.0 Max Units 6.5 4.0 V V mV mA µA µA 150 0.5 0.3 0.4 Charge Current = 200mA VBAT = 4.25V, EN_BAT = GND VBAT = 4V, ADP Pin Open 4.158 2.85 4.20 0.5 3.0 1 1 2 4.242 3.15 VCO(REG) 0.1 Measured from VCO(REG) 15 V 500 mA % V 1.1 W 10 2 800 VADP = 5.5V 0.9 1.6 0.4 0.4 8 STAT Pin Sinks 4mA ICH = 100mA V % V 4.4 10 10 V V V mA V % % 1. The AAT2557 is guaranteed to meet performance specifications over the -40°C to +85°C operating temperature range and is assured by design, characterization, and correlation with statistical process controls. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202178A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 24, 2012 5 DATA SHEET AAT2557 500mA Battery Charger and 300mA LDO Regulator for Portable Systems Typical Characteristics – Battery Charger Charging Current vs. Battery Voltage Constant Charging Current vs. Set Resistor Values (VADP = 5V) 600 1000 RSET = 3.24kΩ 100 ICH (mA) ICH (mA) 500 10 400 RSET = 5.36kΩ 300 RSET = 8.06kΩ 200 100 1 0 1 10 100 1000 2.7 2.9 RSET = 16.2kΩ RSET = 31.6kΩ 3.1 3.7 3.3 RSET (kΩ) 3.5 3.9 4.1 4.3 VBAT (V) Constant Output Charge Voltage Regulation vs. Adapter Voltage Constant Output Charge Voltage Regulation vs. Temperature (RSET = 8.06kΩ) 4.206 4.23 RSET = 8.06kΩ 4.22 4.202 4.200 VCO(REG) (V) VCO_REG (V) 4.204 RSET = 31.6kΩ 4.198 4.196 4.194 4.5 4.75 5 5.25 5.5 5.75 6 6.25 -50 -25 0 25 50 75 100 Temperature (°C) Constant Charging Current vs. Temperature (RSET = 8.06kΩ) (RSET = 8.06kΩ) 210 220 208 210 205 VBAT = 3.3V ICH (mA) ICH (mA) 4.19 4.17 6.5 Constant Charging Current vs. Adapter Voltage 200 190 VBAT = 3.6V VBAT = 4V 203 200 198 195 180 193 4 4.25 4.5 4.75 5 5.25 5.5 VADP (V) 6 4.20 4.18 VADP (V) 170 4.21 5.75 6 6.25 190 6.5 -50 -25 0 25 50 Temperature (°C) Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202178A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 24, 2012 75 100 DATA SHEET AAT2557 500mA Battery Charger and 300mA LDO Regulator for Portable Systems Typical Characteristics – Battery Charger Recharging Voltage Threshold vs. Temperature Preconditioning Voltage Threshold vs. Temperature (RSET = 8.06kΩ) (RSET = 8.06kΩ) 4.18 3.03 4.16 3.02 VMIN (V) VRCH (V) 4.14 4.12 4.10 4.08 3 2.99 4.06 2.98 4.04 4.02 3.01 -50 -25 0 25 50 75 2.97 -50 100 -25 0 Temperature (°C) (RSET = 8.06kΩ) ITRICKLE (mA) ITRICKLE (mA) 20.4 20.2 20.0 19.8 19.6 RSET = 5.36kΩ 30 RSET = 8.06kΩ 20 0 25 50 75 100 Temperature (°C) RSET = 31.6kΩ RSET = 16.2kΩ 4 4.2 4.4 4.6 4.8 5 5.2 5.4 5.6 5.8 6 6.2 6.4 VADP (V) Operating Current vs. Temperature Sleep Mode Current vs. Supply Voltage (RSET = 8.06kΩ) (RSET = 8.06kΩ) 800 550 700 500 450 400 500 400 300 25°C 200 350 300 -50 85°C 600 ISLEEP (nA) IOP (µA) 40 10 19.4 0 100 RSET = 3.24kΩ 50 20.6 -25 75 60 20.8 -50 50 Preconditioning Charge Current vs. Adapter Voltage Preconditioning Charge Current vs. Temperature 19.2 25 Temperature (°C) -40°C 100 -25 0 25 50 Temperature (°C) 75 0 100 4 4.25 4.5 4.75 5 5.25 5.5 5.75 6 6.25 6.5 VADP (V) 25°C 85°C Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202178A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 24, 2012 -40°C 7 DATA SHEET AAT2557 500mA Battery Charger and 300mA LDO Regulator for Portable Systems Typical Characteristics – Battery Charger Enable Input High Voltage vs. Adapter Voltage Enable Input Low Voltage vs. Adapter Voltage (RSET = 8.06kΩ) (RSET = 8.06kΩ) 1.2 1.1 1 0.9 25°C 0.8 0.7 85°C 0.9 0.8 4.25 4.5 4.75 5 5.25 5.5 5.75 6 25°C 0.7 0.6 4 -40°C 1 -40°C VEN_BAT(L) (V) VEN_BAT(H) (V) 1.1 6.25 6.5 VADP (V) 4 4.25 4.5 4.75 5 5.25 5.5 85°C 5.75 6 6.25 6.5 VADP (V) Typical Characteristics – LDO Regulator Dropout Voltage vs. Temperature 1.250 540 1.225 480 Dropout Voltage (mV) VEN_LDO(L) and VEN_LDO(H) (V) Enable Input High and Low Voltages vs. Input Voltage 1.200 VEN(H) 1.175 1.150 1.125 VEN(L) 1.100 1.075 1.050 2.5 3.0 3.5 4.0 4.5 5.0 360 300 180 120 60 Input Voltage (V) IL = 50mA -40 -30 -20 -10 0 Dropout Voltage vs. Output Current 3.2 IOUT = 300mA IOUT = 150mA 2.6 2.4 2.0 2.7 IOUT = 10mA IOUT = 100mA IOUT = 50mA 450 400 350 300 2.9 3.0 3.1 3.2 3.3 85°C 250 200 150 -40°C 100 25°C 50 0 2.8 Input Voltage (V) 8 Dropout Voltage (mV) Output Voltage (V) 500 IOUT = 0mA 2.8 2.2 10 20 30 40 50 60 70 80 90 100 110 120 Temperature (°C) Dropout Characteristics 3.0 IL = 100mA IL = 150mA 240 0 5.5 IL = 300mA 420 0 50 100 150 200 Output Current (mA) Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202178A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 24, 2012 250 300 DATA SHEET AAT2557 500mA Battery Charger and 300mA LDO Regulator for Portable Systems Typical Characteristics – LDO Regulator Quiescent Current vs. Temperature Ground Current vs. Input Voltage 90 100 Quiescent Current (µA) Ground Current (µA) 80 70 60 IOUT=300mA 50 IOUT=150mA IOUT=50mA 40 IOUT=0mA 30 IOUT=10mA 20 10 0 90 80 70 60 50 40 30 20 10 0 2 2.5 3 3.5 4 4.5 -40 -30 -20 -10 5 Input Voltage (V) LDO Initial Turn-On Response Time 1.202 5 Input Voltage (top) (V) Output Voltage (V) 6 1.201 1.200 1.199 1.198 1.197 10 20 30 40 50 60 70 80 4 3 2 3 1 2 0 1 0 90 100 Time (50µs/div) Temperature (°C) LDO Turn-Off Response Time LDO Turn-On Time from Enable (IOUT = 100mA) (VIN Present) 4 1 3 0 2 1 0 Enable Voltage (top) (V) Enable Voltage (top) (V) 2 5 0 3 2 1 0 Output Voltage (bottom) (V) 3 Output Voltage (bottom) (V) 4 Time (5µs/div) Output Voltage (bottom) (V) 1.203 0 10 20 30 40 50 60 70 80 90 100 110 120 Temperature (°C) Output Voltage vs. Temperature 1.196 -40 -30 -20 -10 0 Time (5µs/div) Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202178A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 24, 2012 9 DATA SHEET AAT2557 500mA Battery Charger and 300mA LDO Regulator for Portable Systems Typical Characteristics – LDO Regulator Load Transient Response Line Transient Response (VOUT = 2.8V) VIN 4 3.00 VOUT 2.99 2.98 Time (100µs/div) Output Voltage (top) (V) 5 Output Voltage (bottom) (V) Input Voltage (top) (V) 6 2.85 VOUT 2.80 2.75 100 0 IOUT Time (100µs/div) Load Transient Response 300mA 3.0 2.9 2.8 2.7 VOUT 400 300 200 IOUT 100 0 Output Current (bottom) (mA) Output Voltage (top) (V) (VOUT = 2.8V) Time (10µs/div) 10 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202178A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 24, 2012 Output Current (bottom) (mA) 2.90 DATA SHEET AAT2557 500mA Battery Charger and 300mA LDO Regulator for Portable Systems Functional Block Diagram Reverse Blocking BAT ADP OverTemperature Protection Charge Control - STAT Constant Current + + ISET - VREF UVLO EN_BAT INLDO Err. Amp. BYP VREF OverCurrent Protection OUTLDO EN_LDO Functional Description The AAT2557 is a high performance power management IC comprised of a lithium-ion/polymer battery charger and a linear regulator. Battery Charger The battery charger is designed for single-cell lithiumion/polymer batteries using a constant current and constant voltage algorithm. The battery charger operates from the adapter/USB input voltage range from 4V to 6.5V. The adapter/USB charging current level can be programmed up to 500mA for rapid charging applications. A status monitor output pin is provided to indicate GND the battery charge state by directly driving one external LED. Internal device temperature and charging state are fully monitored for fault conditions. Fault condition can be one of the following: • Battery over-voltage (OV) • Battery temperature sense hot or cold • Battery charge timer time-out • Chip thermal shutdown In the event of an over-voltage or over-temperature failure, the device will automatically shut down, protecting the charging device, control system, and the battery under charge. Other features include an integrated reverse blocking diode and sense resistor. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202178A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 24, 2012 11 DATA SHEET AAT2557 500mA Battery Charger and 300mA LDO Regulator for Portable Systems Linear Regulator Protection Circuitry The advanced circuit design of the linear regulator has been specifically optimized for very fast start-up. This proprietary CMOS LDO has also been tailored for superior transient response characteristics. These traits are particularly important for applications that require fast power supply timing. Over-Voltage Protection The high-speed turn-on capability is enabled through implementation of a fast-start control circuit which accelerates the power-up behavior of fundamental control and feedback circuits within the LDO regulator. The LDO regulator output has been specifically optimized to function with low-cost, low-ESR ceramic capacitors; however, the design will allow for operation over a wide range of capacitor types. The regulator comes with complete short-circuit and thermal protection. The combination of these two internal protection circuits gives a comprehensive safety system to guard against extreme adverse operating conditions. The regulator features an enable/disable function. The EN_LDO pin is active high and is compatible with CMOS logic levels. To assure the LDO regulator will turn on, the EN_LDO control level must be greater than 1.5V. The LDO regulator will be disabled when the voltage on the EN_LDO pin falls below 0.6V. If the enable function is not needed in a specific application, it may be tied to INLDO to keep the LDO regulator in a continuously on state. Battery Charger Under-Voltage Lockout The AAT2557 has internal circuits for UVLO and power on reset features. If the ADP supply voltage drops below the UVLO threshold, the battery charger will suspend charging and shut down. When power is reapplied to the ADP pin or the UVLO condition recovers, the system charge control will automatically resume charging in the appropriate mode for the condition of the battery. 12 When the voltage on the BAT pin exceeds the overvoltage protection threshold (VOVP = 4.4V) it is defined as an over-voltage protection event. If this over-voltage condition occurs, the charger control circuitry will shut down the device. The charger will resume normal charging operation after the over-voltage condition is removed. Over-Temperature Protection The AAT2557’s battery charger has a thermal protection circuit which will shut down charging functions when the internal die temperature exceeds the preset thermal limit threshold (145°C). Once the internal die temperature falls below the thermal limit, normal charging operation will resume. The AAT2557’s LDO also has an internal thermal protection circuit which will turn on when the device die temperature exceeds 145°C. The internal thermal protection circuit will actively turn off the LDO regulator output pass device to prevent the possibility of over temperature damage. The LDO regulator output will remain in a shutdown state until the internal die temperature falls back to 12°C below the 145°C trip point. Short-Circuit Protection The AAT2557’s LDO contains an internal short-circuit protection circuit that will trigger when the output load current exceeds the internal threshold limit. Under short-circuit conditions, the output of the LDO regulator will be current limited until the short-circuit condition is removed from the output or until the package power dissipation exceeds the device thermal limit. The combination and interaction between the short-circuit and thermal protection systems allow the LDO regulator to withstand indefinite short-circuit conditions without sustaining permanent damage. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202178A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 24, 2012 DATA SHEET AAT2557 500mA Battery Charger and 300mA LDO Regulator for Portable Systems Battery Charging Operation Battery charging commences only after checking several conditions in order to maintain a safe charging environment. The input supply (ADP) must be above the minimum operating voltage (UVLO) and the enable pin must be high (internally pulled down). When the battery is connected to the BAT pin, the charger checks the condition of the battery and determines which charging mode to apply. If the battery voltage is below VMIN, the charger begins battery pre-conditioning by charging at 10% of the programmed constant current; e.g., if the programmed current is 150mA, then the pre-conditioning current (trickle charge) is 15mA. Pre-conditioning is purely a safety precaution for a deeply discharged cell and will also reduce the power dissipation in the internal series MOSFET pass device when the input-output voltage differential is at its highest. Pre-conditioning continues until the battery voltage reaches VMIN (see Figure 1). At this point, the charger begins constant-current charging. The current level for this mode is programmed using a single resistor from Battery UVLO Trickle Charge Constant Current Charge Phase (CC) the ISET pin to ground. Programmed current can be set from a minimum 15mA up to a maximum of 500mA. Constant current charging will continue until the battery voltage reaches the voltage regulation point, VBAT and the battery charger begins constant voltage mode. The regulation voltage is factory programmed to a nominal 4.2V and will continue charging until the charging current has reduced to 10% of the programmed current. After the charge cycle is complete, the pass device turns off and the device automatically goes into a power-saving sleep mode. During this time, the series pass device will block current in both directions, preventing the battery from discharging through the IC. The battery charger will remain in sleep mode, even if the charger source is disconnected, until one of the following events occurs: the battery terminal voltage drops below the VRCH threshold; the charger EN pin is recycled; or the charging source is reconnected. In all cases, the charger will monitor all parameters and resume charging in the most appropriate mode. Constant Voltage Charge Phase (CV) Constant Current Charge Phase Constant Voltage Charge Phase Recharge Phase ICH_CC Termination Phase I CH_ CC Termination Phase VCO( REG) VRCH VMIN I CH_ TERM when VUVLO I CH_ TKL VBAT = VCO( REG) I CH_ TERM when VBAT = VCO( REG) Figure 1: Current vs. Voltage Profile During Charging Phases. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202178A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 24, 2012 13 DATA SHEET AAT2557 500mA Battery Charger and 300mA LDO Regulator for Portable Systems Battery Charging System Operation Flow Chart Enable No Power On Reset Yes Power Input Voltage VADP > VUVLO Yes Shut Down Yes Fault Conditions Monitoring OV, OT Charge Control No Preconditioning Test V MIN > VBAT Yes Preconditioning (Trickle Charge) Yes Constant Current Charge Mode Yes Constant Voltage Charge Mode No No Recharge Test V RCH > VBAT Yes Current Phase Test V CO(REG) > VBAT No Voltage Phase Test IBAT > ICH_TERM No Charge Completed 14 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202178A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 24, 2012 DATA SHEET AAT2557 500mA Battery Charger and 300mA LDO Regulator for Portable Systems Application Information Soft Start / Enable The EN_BAT pin is internally pulled down. When pulled to a logic high level, the battery charger is enabled. When left open or pulled to a logic low level, the battery charger is shut down and forced into the sleep state. Charging will be halted regardless of the battery voltage or charging state. When it is re-enabled, the charge control circuit will automatically reset and resume charging functions with the appropriate charging mode based on the battery charge state and measured cell voltage from the BAT pin. Event Description Status No battery charging activity Battery charging via adapter or USB port Charging completed OFF ON OFF Table 1: LED Status Indicator. Constant Charge Current ICH_CC (mA) Set Resistor Value (kW) 500 400 300 250 200 150 100 50 40 30 20 15 3.24 4.12 5.36 6.49 8.06 10.7 16.2 31.6 38.3 53.6 78.7 105 The LDO is enabled when the EN_LDO pin is pulled high. The control and feedback circuits have been optimized for high-speed, monotonic turn-on characteristics. Adapter or USB Power Input Constant current charge levels up to 500mA may be programmed by the user when powered from a sufficient input power source. The battery charger will operate from the adapter input over a 4.0V to 6.5V range. The fast charge constant current charge level is user programmable with a set resistor placed between the ISET pin and ground. The accuracy of the fast charge, as well as the preconditioning trickle charge current, is dominated by the tolerance of the set resistor used. For this reason, a 1% tolerance metal film resistor is recommended for the set resistor function. Fast charge constant current levels from 15mA to 500mA may be set by selecting the appropriate resistor value from Table 2. Charge Status Output The AAT2557 provides battery charge status via a status pin. This pin is internally connected to an N-channel open drain MOSFET, which can be used to drive an external LED. The status pin can indicate several conditions, as shown in Table 1. 1000 ICH_CC (mA) Programming Charge Current Table 2: RSET Values. 100 10 1 1 10 100 1000 RSET (kΩ) Figure 2: Constant Charging Current vs. Set Resistor Values. The LED should be biased with as little current as necessary to create reasonable illumination; therefore, a ballast resistor should be placed between the LED cathode and the STAT pin. LED current consumption will add to the overall thermal power budget for the device package, hence it is good to keep the LED drive current to a minimum. 2mA should be sufficient to drive most lowcost green or red LEDs. It is not recommended to exceed 8mA for driving an individual status LED. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202178A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 24, 2012 15 DATA SHEET AAT2557 500mA Battery Charger and 300mA LDO Regulator for Portable Systems The required ballast resistor values can be estimated using the following formulas: R1= (VADP - VF(LED)) ILED Example: R1 = (5.5V - 2.0V) = 1.75kΩ 2mA Note: Red LED forward voltage (VF) is typically 2.0V @ 2mA. Thermal Considerations The AAT2557 is offered in a TSOPJW-14 package which can provide up to 625mW of power dissipation when it is properly bonded to a printed circuit board and has a maximum thermal resistance of 160°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 IC will also have an effect 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: Where: PD VADP VBAT ICH = = = = Total Power Dissipation by the Device ADP/USB Voltage Battery Voltage as Seen at the BAT Pin Constant Charge Current Programmed for the Application IOP = Quiescent Current Consumed by the Charger IC for Normal Operation [0.5mA] VINLDO = Input Voltage as Seen at the INLDO Pin VOUTLDO = Output Voltage as Seen at the OUTLDO Pin IOUTLDO = LDO Load Current IQLDO = LDO Quiescent Current By substitution, we can derive the maximum charge current before reaching the thermal limit condition (thermal cycling). The maximum charge current is the key factor when designing battery charger applications. ICH(MAX) = (PD(MAX) - VIN · IOP) VIN - VBAT (TJ(MAX) - TA) - V · I IN OP θJA ICH(MAX) = VIN - VBAT In general, the worst condition is the greatest voltage drop across the IC, when battery voltage is charged up to the preconditioning voltage threshold. Capacitor Selection Linear Regulator Input Capacitor (TJ(MAX) - TA) PD(MAX) = θJA Where: PD(MAX) = Maximum Power Dissipation (W) qJA = Package Thermal Resistance (°C/W) TJ(MAX) = Maximum Device Junction Temperature (°C) [135°C] TA = Ambient Temperature (°C) PD = [(VADP - VBAT) · ICH + (VADP · IOP)] + (VINLDO - VOUTLDO) IOUTLDO + VINLDO · IQLDO 16 An input capacitor greater than 1µF will offer superior input line transient response and maximize power supply ripple rejection. Ceramic, tantalum, or aluminum electrolytic capacitors may be selected since there is no specific capacitor ESR requirement for CINLDO. However, for best performance of the LDO regulator at maximum load current output, ceramic capacitors are recommended for CINLDO due to their inherent capability over tantalum capacitors to withstand input current surges from low impedance sources such as batteries in portable devices. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202178A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 24, 2012 DATA SHEET AAT2557 500mA Battery Charger and 300mA LDO Regulator for Portable Systems Battery Charger Input Capacitor In general, it is good design practice to place a decoupling capacitor between the ADP pin and GND. 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 adapter input is to be used in a system with an external power supply source, such as a typical AC-to-DC wall adapter, then a CADP capacitor in the range of 10µF should be used. A larger input capacitor in this application will minimize switching or power transient effects when the power supply is “hot plugged” in. Linear Regulator Output Capacitor For proper load voltage regulation and operational stability, a capacitor is required between OUT and GND. The COUTLDO capacitor connection to the LDO regulator ground pin should be made as directly as practically possible for maximum device performance. Since the regulator has been designed to function with very low ESR capacitors, ceramic capacitors in the 1.0µF to 10µF range are recommended for best performance. Applications utilizing the exceptionally low output noise and optimum power supply ripple rejection should use 2.2µF or greater for COUTLDO. In low output current applications, where output load is less than 10mA, the minimum value for COUTLDO can be as low as 0.47µF. may be required to prevent the device from cycling on and off when no battery is present. Bypass Capacitor and Low Noise Applications A bypass capacitor pin is provided to enhance the low noise characteristics of the AAT2557 LDO regulator. The bypass capacitor is not necessary for operation of the AAT2557. However, for best device performance, a small ceramic capacitor should be placed between the bypass pin (BYP) and the device ground pin (GND). The value of CBYP may range from 470pF to 10nF. For lowest noise and best possible power supply ripple rejection performance, a 10nF capacitor should be used. To practically realize the highest power supply ripple rejection and lowest output noise performance, it is critical that the capacitor connection between the BYP pin and GND pin be direct and PCB traces should be as short as possible. Refer to the PCB Layout Recommendations section of this document for examples. There is a relationship between the bypass capacitor value and the LDO regulator turn-on and turnoff time. In applications where fast device turn-on and turn-off time are desired, the value of CBYP should be reduced. In applications where low noise performance and/or ripple rejection are less of a concern, the bypass capacitor may be omitted. The fastest device turn-on time will be realized when no bypass capacitor is used. Battery Charger Output Capacitor Printed Circuit Board Layout Considerations The AAT2557 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 AAT2557 is to be used in applications where the battery can be removed from the charger, such as with desktop charging cradles, an output capacitor greater than 10µF For the best results, it is recommended to physically place the battery pack as close as possible to the AAT2557 BAT pin. To minimize voltage drops on the PCB, keep the high current carrying traces adequately wide. The input capacitors should connect as closely as possible to ADP and INLDO. Manufacturer Part Number Value (µF) Voltage Rating Temp. Co. Case Size Murata Murata Murata Murata Murata Murata Murata Murata GRM21BR61A106KE19 GRM188R60J475KE19 GRM188R61A225KE34 GRM188R60J225KE19 GRM188R61A105KA61 GRM185R60J105KE26 GRM188F51H103ZA01 GRM155F51H103ZA01 10 4.7 2.2 2.2 1.0 1.0 0.01 0.01 10 6.3 10 6.3 10 6.3 50 50 X5R X5R X5R X5R X5R X5R Y5V Y5V 0805 0603 0603 0603 0603 0603 0603 0402 Table 3: Surface Mount Capacitors. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202178A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 24, 2012 17 DATA SHEET AAT2557 500mA Battery Charger and 300mA LDO Regulator for Portable Systems Figure 3: AAT2557 Evaluation Board Top Side Layout. ADP TB1 Figure 4: AAT2557 Evaluation Board Bottom Side Layout. 7 GND R2 1.5k JP2 JP3 INLDO 1 GND 10 JP1 INLDO INLDO C3 4.7µF GND EN_BAT BAT TB2 BAT 6 EN_LDO OUTLDO BYP 14 13 12 8 2 C4 2.2µF 11 STAT GND GND GND GND GND GND 3 TP1 INLDO AAT2557ITO 9 4 EN_LDO TSOPJW-14 ADP C1 10µF D1 GND U1 C5 10nF ISET C2 10µF 5 R1 8.06k GND Figure 5: AAT2557 Evaluation Board Schematic. 18 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202178A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 24, 2012 DATA SHEET AAT2557 500mA Battery Charger and 300mA LDO Regulator for Portable Systems Ordering Information Package Marking1 Part Number (Tape and Reel)2 TSOPJW-14 TSOPJW-14 VKXYY 9ZXYY AAT2557ITO-CT-T1 AAT2557ITO-CW-T1 Skyworks Green™ products are compliant with all applicable legislation and are halogen-free. For additional information, refer to Skyworks Definition of Green™, document number SQ04-0074. Legend Voltage Code 1.2 1.5 1.8 1.9 2.5 2.6 2.7 2.8 2.85 2.9 3.0 3.3 4.2 E G I Y N O P Q R S T W C 1. XYY = assembly and date code. 2. Sample stock is generally held on part numbers listed in BOLD. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202178A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 24, 2012 19 DATA SHEET AAT2557 500mA Battery Charger and 300mA LDO Regulator for Portable Systems Package Information TSOPJW-14 2.85 ± 0.20 2.40 ± 0.10 0.20 +- 0.10 0.05 0.40 BSC Top View 0.04 REF 0.05 +- 0.05 0.04 Side View 0.15 ± 0.05 + 0.05 1.05 - 0.00 + 0.000 1.00 - 0.075 3.05 +- 0.05 0.10 4° ± 4° 0.45 ± 0.15 2.75 ± 0.25 End View All dimensions in millimeters. Copyright © 2012 Skyworks Solutions, Inc. All Rights Reserved. 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Additional information, including relevant terms and conditions, posted at www.skyworksinc.com, are incorporated by reference. 20 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202178A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 24, 2012