DATA SHEET AAT3691 Dual Input 1.6A Linear Charger with 28V OVP in a 3x4 TDFN Package General Description Features The AAT3691 BatteryManager™ is an integrated single cell Lithium-Ion (Li-Ion) battery charger IC, designed to operate from USB ports, AC adapter inputs, or from a cellular phone charger adapter up to an input voltage of typical 6.75V. For increased safety, The AAT3691 also includes over-voltage input protection (OVP) up to 28V. • Dual Input USB and AC Adapter Input ▪ Programmable Constant Current from 100mA to 1.6A for ADP Charge ▪ Programmable Constant Current from 50mA to 0.5A for USB Charge • No Battery Present Input Detection • 3.0V ~ 6.75V (typical) Input Voltage Range • Over-Voltage Input Protection up to 28V • High Level of Integration with Internal: ▪ Power Device ▪ Reverse Current Blocking ▪ Current Sensing • Automatic Recharge Sequencing • Fast Over-Voltage Protection Turn Off and Release Turn On Time • Full Battery Charge Auto Turn Off/Sleep Mode/Charge Termination • Charge Status Indicator • Automatic Charge Reduction • Automatic Trickle Charge for Battery Preconditioning • Thermal Shutdown Protection • Active Digital Thermal Loop Control • Power On Reset and Soft Start • Active Low Enable with Internal 200kΩ Resistor PullDown to GND • 3x4mm TDFN Package The AAT3691 precisely regulates battery charge voltage and current for 4.2V Li-Ion battery cells. The charge current can be programmed up to 1.6A for ADP charging and 0.5A for USB charging by external resistors on the ADPSET/USBSET pins. In the case of an over-voltage condition of ADP or USB input power exceeding typical 6.75V, the internal series switch opens, blocking the damage to the battery and charging circuitry. The AAT3691 also includes a no-battery present input (NOBAT). When the NOBAT indicates that no battery is present, OVP block will prevent the input power from passing through the OVP block and suspend the charging function. Battery charging status is continuously monitored for fault conditions. In the event of a battery over voltage or chip over thermal failure, the charger will automatically shutdown, protecting the charging device, control system and battery, until the fault condition is removed. The open drain status monitor output pin (STAT) is adopted to report battery charging activity by active low. The AAT3691 comes in a thermally enhanced, spacesaving, Pb-free 16-pin 3x4 mm TDFN package and is specified for operation over the -40°C to +85°C temperature range. Applications • • • • Digital Still Cameras Mobile Phones Personal Data Assistants (PDAs) Other Li-Ion Battery Powered Devices Typical Application BATT+ USB USBIN Battery Pack BAT 1μF 10μF USBCH IC BATT- 2.2μF AAT3691 Voltage Source NOBAT NOBAT R STAT ADPIN 1μF 2.2μF EN ADP USBSET ADPCH ADPSET GND ON/OFF RADPSET RUSBSET Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 201894B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 27, 2012 1 DATA SHEET AAT3691 Dual Input 1.6A Linear Charger with 28V OVP in a 3x4 TDFN Package Pin Descriptions Pin # Name Type 1 2. 3 4 5, 7, 10 6 8, 9 11 12 13 14 15 16 USB USBCH ADP ADPCH IC STAT GND EN ADPSET USBSET NOBAT N/C BAT I I/O I I/O I O I I I I O Function Input from USB port connector Output from USB OVP stage, input to battery charger. Decouple with 2.2μF capacitor. Input from adapter port connector Output from ADP OVP stage, input to battery charger. Decouple with 2.2μF capacitor. Internally used. Connect to GND or leave floating. Charge status indication pin, open drain. Connect to power ground Active low enable with internal 200kΩ resistor pull-down to GND. ADP charge current programming input pin. USB charge current programming input pin. No battery present input. Logic “High“ indicates no battery. Internal 1.6MΩ pull-high resistor. No connection. Connect to lithium-ion battery. Pin Configuration TDFN34-16 (Top View) USB USBCH ADP ADPCH IC STAT IC GND 2 1 16 2 15 3 14 4 13 5 12 6 11 7 10 8 9 BAT N/C NOBAT USBSET ADPSET EN IC GND Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 201894B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 27, 2012 DATA SHEET AAT3691 Dual Input 1.6A Linear Charger with 28V OVP in a 3x4 TDFN Package Absolute Maximum Ratings1 Symbol VADP ,VUSB VADPCH,, VUSBCH VN TJ TLEAD Description ADP, USB input continuous Charger input continuous BAT, STAT, EN, ADPSET , USBSET, NOBAT, IC Operating Junction Temperature Range Maximum Soldering Temperature (at Leads) Value Units 28 -0.3 to 7.5 -0.3 to 7.5 + 0.3 -40 to 150 300 V V V C C Value Units 50 2 C/W W Thermal Information2 Symbol JA PD Description Maximum Thermal Resistance (TDFN 3x4) Maximum Power Dissipation 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 a FR4 board. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 201894B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 27, 2012 3 DATA SHEET AAT3691 Dual Input 1.6A Linear Charger with 28V OVP in a 3x4 TDFN Package Electrical Characteristics1 VADP = VUSB = 5V, TA = -25°C to +85°C, unless otherwise noted. Typical values are at TA = 25°C. Symbol Description Operation VADP_MAX, Input Over-Voltage Protection Range VUSB_MAX ADP and USB Normal Operating Input Voltage VADP, VUSB Range IADP_OP, Operating Current IUSB_OP ISD(OFF) Shutdown Supply Current ISTANDBY Standby Mode Current Leakage Current from BAT Pin IBAT Over-Voltage Protection Over-Voltage Protection Trip Voltage VOVPT Hysteresis Battery Charger VUVLO_ADP, Under-Voltage Lockout Threshold VUVLO_USB UVLO Hysteresis Voltage Regulation VBAT_EOC Output Charge Voltage Regulation VCH/VCH Output Charge Voltage Tolerance VMIN Preconditioning Voltage Threshold VRCH Conditions Min 3.0 VADP or VUSB = 5V, Charge current = 100mA, EN = 0V VADP or VUSB = 5V, EN = 5V Charge Terminated VBAT = 4V, USB and ADP open Rising edge 0.5 8 300 1 6.5 6.75 300 Rising edge Max Units 28 V 6.5 V 1.5 mA 4 μA μA μA 7.0 V mV 3.0 V mV 4.242 V % V 150 4.158 2.4 Battery Recharge Voltage Threshold Battery Charging Device Charging and OVP Total ON Resistance RDS(ON) Current Regulation ADP Charge Current Programmable Range ILIM_ADP ILIM_USB USB Charge Current Programmable Range ICH_CC Constant-Current Mode Charge Current VADPSET, ADPSET, USBSET Pin Voltage VUSBSET KIADPSET Charge Current Set Factor: ICH_CC/IADPSET KIUSBSET Charge Current Set Factor: ICH_CC/IUSBSET Typ 4.20 0.5 2.6 VBAT_EOC - 0.1 VADP or VUSB = 5V, TA = 25°C VBAT = 3.6V 100 50 -10 2.8 V 600 m 1600 500 10 mA mA % 2 Constant current mode, VBAT = 3.6V Constant current mode, VBAT = 3.6V V 800 800 ICH_TRK Trickle Charge Current RADPSET = 8k 5 10 15 ICH_TERM Charge Termination Threshold Current ICH_CC ≥ 800mA 8 10 12 % ICH_CC % 1. The AAT3691 is guaranteed to meet performance specifications over the -40°C to +85°C operating temperature range and are assured by design, characterization and correlation with statistical process controls. 4 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 201894B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 27, 2012 DATA SHEET AAT3691 Dual Input 1.6A Linear Charger with 28V OVP in a 3x4 TDFN Package Electrical Characteristics (continued)1 VADP = VUSB = 5V, TA = -25°C to +85°C, unless otherwise noted. Typical values are at TA = 25°C. Symbol Description Logic Control / Battery Protection Input High Threshold VEN#(H) VEN#(L) Input Low Threshold VSTAT Output Low Voltage ISTAT STAT Pin Current Sink Capability VNOBAT(H) No Battery Present Input High Threshold VNOBAT(L) No Battery Present Input Low Threshold VBOVP Battery Over-Voltage Protection Threshold TRESPOV Over-Voltage Response Time TOVPON OVP Switch OVP Release Turn-On Delay Time TOVPSTARTON OVP Switch Start Up Turn-On Delay Time TOVPR OVP Switch Turn-On Rise Time TSHDN Chip Thermal Shutdown Temperature Conditions VADP = 5V Min Typ Max 4 0.4 0.4 8 1.2 STAT pin sinks 4mA 1.2 0.4 4.4 VADP, VUSB voltage step up signal from 6V to 8V VADP voltage step down signal from 8V to 6V, RLOAD = 10, CADPCH = 1μF VADP voltage step up signal from 0V to 5V, RLOAD = 10, CADPCH = 1μF RLOAD = 10, CADPCH = 1μF Thermal Shutdown Threshold Hysteresis 0.5 1.0 Units V V V mA V V V μs 5 μs 130 μs 100 140 15 μs °C 1. The AAT3691 is guaranteed to meet performance specifications over the -40°C to +85°C operating temperature range and are 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 201894B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 27, 2012 5 DATA SHEET AAT3691 Dual Input 1.6A Linear Charger with 28V OVP in a 3x4 TDFN Package Typical Characteristics Over-Voltage Protection vs. Temperature End of Charge Voltage vs. Supply Voltage (RADPSET = 1kΩ, RUSBSET = 3.2kΩ) 4.22 6.80 4.21 6.70 6.65 Power sweep low to high Power sweep high to low 6.60 VEOC (V) VADP or VUSB (V) 6.75 4.20 4.19 6.55 USB ADP 6.50 -40 -20 0 20 40 60 4.18 4.4 80 4.8 5.2 Temperature (°C) ICHARGE vs. RADPSET 6.0 6.4 6.8 ICHARGE vs. RUSBSET 10000 1000 ICHARGE (mA) ICHARGE (mA) 5.6 VADP or VUSB (V) 1000 100 10 100 10 1 10 100 1 10 RADPSET (kΩ) 100 RUSBSET (kΩ) Battery Recharge Voltage Threshold vs. Supply Voltage Battery Recharge Voltage Threshold vs. Temperature (RADPSET = 1kΩ; RUSBSET = 3.2kΩ; CBAT = 22μF) (VADP = VUSB = 5V; RADPSET = 1kΩ; RUSBSET = 3.2kΩ; CBAT = 22μF) 4.10 4.10 4.08 VRCH (V) VRCH (V) 4.08 4.06 4.04 4.02 4.06 4.04 4.00 USB ADP 3.98 3.96 4.5 4.9 5.3 5.7 VADP or VUSB (V) 6 6.1 6.5 4.02 4.00 -40 USB ADP -20 0 20 40 60 Temperature (°C) Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 201894B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 27, 2012 80 DATA SHEET AAT3691 Dual Input 1.6A Linear Charger with 28V OVP in a 3x4 TDFN Package Typical Characteristics End of Charge Voltage vs. Temperature Charge Current vs. Temperature (RADPSET = 1kΩ; RUSBSET = 3.2kΩ) (VADP = VUSB = 5V; VBAT = 3.6V; RADPSET = 1kΩ; RUSBSET = 3.2kΩ) 4.22 1800 USB ADP 1600 1400 ICH (mA) VEOC (V) 4.21 4.20 1200 1000 800 600 4.19 400 ADP USB 200 4.18 -40 -20 0 20 40 60 0 -40 80 -20 0 Temperature (°C) 20 40 60 80 Temperature (°C) Charging Current vs. Battery Voltage USB Charging Current vs. Supply Voltage (VADP = VUSB = 5V; RADPSET = 1kΩ; RUSBSET = 3.2kΩ) (RUSBSET = 3.2kΩ) 600 1800 ADP USB 1600 500 ICH_USB (mA) ICH (mA) 1400 1200 1000 800 600 400 400 300 200 VBAT = 3.3V VBAT = 3.6V VBAT = 3.9V 100 200 0 2.5 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 0 4.0 4.5 4.4 4.8 VBAT (V) 5.2 5.6 6.0 6.4 6.8 VUSB (V) ADP Charging Current vs. Supply Voltage USB Charging Current vs. Supply Voltage (RADPSET = 1kΩ) (RUSBSET = 3.2kΩ) 600 1800 1600 500 ICH_USB (mA) ICH_ADP (mA) 1400 1200 1000 800 600 VBAT = 3.3V VBAT = 3.6V VBAT = 3.9V 400 200 0 4.0 4.4 4.8 5.2 5.6 VADP (V) 6.0 6.4 400 300 -40°C 0°C 25°C 50°C 85°C 200 100 6.8 0 4.0 4.4 4.8 5.2 5.6 6.0 6.4 6.8 VUSB (V) Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 201894B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 27, 2012 7 DATA SHEET AAT3691 Dual Input 1.6A Linear Charger with 28V OVP in a 3x4 TDFN Package Typical Characteristics ADP Charging Current vs. Battery Voltage USB Charging Current vs. Battery Voltage (VADP = 5V) (VUSB = 5V) 1800 600 RSET = 1kΩ RSET = 1.14kΩ RSET = 1.33kΩ RSET = 1.6kΩ RSET = 2kΩ RSET = 3.2kΩ RSET = 5.33kΩ RSET = 16kΩ 1200 900 600 500 ICH_USB (mA) ICH_ADP (mA) 1500 300 RSET = 3.2kΩ RSET = 4kΩ RSET = 5.33kΩ RSET = 8kΩ RSET = 16kΩ RSET = 32kΩ 400 300 200 100 0 0 2.5 2.9 3.3 3.7 4.1 2.5 4.5 3.0 NOBAT High Input Threshold vs. Input Power 1.05 1.00 0.95 0.90 -40°C 25°C 85°C 3.6 4.2 4.8 5.4 6.0 NOBAT VIL (V) NOBAT VIH (V) 0.65 1.10 0.85 0.60 0.55 0.50 -40°C 25°C 85°C 0.45 0.40 3.0 6.6 3.6 4.2 VUSB or VADP (V) 0.80 0.75 1.10 0.70 EN VIL (V) EN VIH (V) 1.20 1.05 1.00 0.95 0.90 -40°C 25°C 85°C 0.85 4.8 5.2 5.6 VUSB or VADP (V) 5.4 6.0 6.6 Enable Input Low Threshold vs. Input Power 1.15 4.4 4.8 VUSB or VADP (V) Enable Input High Threshold vs. Input Power 8 4.5 0.70 1.20 0.80 4.0 4.0 NOBAT Low Input Threshold vs. Input Power 1.15 0.80 3.0 3.5 VBAT (V) VBAT (V) 6.0 6.4 0.65 0.60 0.55 0.50 -40°C 25°C 85°C 0.45 0.40 4.0 4.4 4.8 5.2 5.6 6.0 VUSB or VADP (V) Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 201894B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 27, 2012 6.4 DATA SHEET AAT3691 Dual Input 1.6A Linear Charger with 28V OVP in a 3x4 TDFN Package Functional Block Diagram Reverse Blocking OVP Switch BAT USB OVP Sense and Control CV/Precharge USBCH Current Compare USBSET UVLO Charge Control EN Over-Temp. Protect NOBAT IC Current Compare ADPSET STAT ADPCH Charge Status OVP Sense and Control GND ADP Reverse Blocking Functional Description The AAT3691 is a high performance battery charger designed to charge single cell Lithium Ion or Polymer batteries with up to 1600mA charging current from an adaptor (ADP) power source, or with up to 500mA charging current from an USB power source. The AAT3691 is a stand-alone charging solution, with just a few external component required for complete functionality. Both input paths include a fast turn-off over-voltage protection (OVP) circuit with voltage up to +28V and an under-voltage lockout level of 3.0V. The AAT3691 automatically selects the charging source from USB or ADP according to ADP and USB voltage. The ADP path is always the high priority charging path when ADP voltage is higher than 4.5V. The charging current is determined by the selected charging path and its external set resistor (RSET). USB charging uses an automatic charge reduction loop control allow battery charging with limited available current from a USB port while maintaining the regulated port voltage. This system assures that the battery charge function will not overload a USB port while charging if other system demands also share power with the respective port supply. During adapter charging, high set charging current or high ambient operating temperature may cause the AAT3691 junction temperature to rise up to 110°C. A special digital thermal loop control system is employed to maximize charging current by dynamically decreasing the battery charging current. Thermal protection shuts down the AAT3691's charging function when internal dissipation becomes excessive, while OVP function still works. The junction over-temperature threshold is 140°C with 15°C of hysteresis. Once an over-temperature condition is removed, the charging function automatically recovers. The status monitor output pin (STAT) is designed to indicate the battery charge status with open-drain structure by directly driving one external LED. Battery Charging Operation Regardless of which charge input function is selected (adapter input or USB input), the AAT3691 has three basic modes for the battery charge cycle: preconditioning (trickle) charge, constant current/fast charge, and constant voltage charge. When no automatic charge reduction mode or digital thermal loop is triggered, the charge profile is controlled as shown in Figure 1. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 201894B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 27, 2012 9 DATA SHEET AAT3691 Dual Input 1.6A Linear Charger with 28V OVP in a 3x4 TDFN Package Battery Charge Current Battery Voltage Preconditioning Trickle Charge Phase Constant Current Charge Phase Constant Voltage Charge Phase Charge Complete Voltage I = Max CC Regulated Current Charge Current Battery Voltage Constant Current Mode Voltage Threshold Trickle Charge and Termination Threshold I = CC/10 Time Figure 1: Charge Current vs. Battery Voltage Profile during Charging Phases. Battery charging commences only after the AAT3691 checks several conditions in order to maintain a safe charging environment. The input supply must be above the minimum operating voltage and the enable pin must be low. When the battery is connected to the BAT pin and the NOBAT pin indicates there is a battery connected, the AAT3691 checks the condition of the battery and determines which charging mode to apply. If the battery voltage is below VMIN, then the device begins trickle charging by charging at 10% of the programmed constant current. For example, if the programmed current is 500mA, then the trickle charge current is 50mA. Trickle charging is a safety precaution for a deeply discharged cell and will also reduce the power dissipation in the internal series pass MOSFET when the input-output voltage differential is at its highest. Trickle charging continues until the battery voltage reaches VMIN. At this point, the AAT3691 begins constant current charging. The current value for this mode is programmed by the external resistors from the ADPSET and USBSET pin to ground. Programmed current can be set from a minimum of 100mA up to a maximum of 1.6A for an ADP power source, and from a minimum of 50mA up to a maximum of 500mA for a USB power source. Constant current charging continues until the battery voltage reaches the voltage regulation point, VBAT_EOC. When the battery voltage reaches VBAT_EOC (typical 4.2V), the AAT3691 will switch to constant voltage mode. Constant current charge will continue until the charging current is reduced to 10% of the programmed current. After the charge 10 cycle is complete, the AAT3691 turns off the series pass device and automatically goes into standby mode. During this time, the series pass device will block current in both directions, therefore preventing the battery from discharging through the IC. The AAT3691 remains in standby mode until either 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 AAT3691 will monitor all parameters and resume charging in the most appropriate mode. Over-Voltage Protection In normal operation an OVP switch acts as a slew-rate controlled load switch, connecting and disconnecting the power supply from ADP to ADPCH and USB to USBCH. A low-resistance MOSFET is used to minimize the voltage drop between the voltage source and the charger and to reduce the power dissipation. When the voltage on the input exceeds the 6.75V (typical) voltage limit, the device immediately turns off the internal OVP switch, disconnecting the load from the abnormal voltage and preventing damage to any downstream components. On initial power-up with low and battery present, if VUSB/ADP < VUVLO (3V maximum), the OVP switch is held off; if VUVLO < VUSB/ADP < 6.75V (typical), the OVP switch will turn on after a 130μs typical internal delay; if VUSB/ADP rises above 6.75V (typical), the OVP switch is turned off after a 0.5μs typical internal delay. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 201894B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 27, 2012 DATA SHEET AAT3691 Dual Input 1.6A Linear Charger with 28V OVP in a 3x4 TDFN Package System Operation Flowchart Power On Reset OVP Switch Off Yes NOBAT Indicates No Battery No Enable Adapter Charge No Yes No USBCH = ADPCH = 0V Preconditioning Test VMIN > VBAT OVP (6.75V) ≥ V USB or VADP ≥ VUVLO_ADP or VUVLO_USB (3V) No Yes Preconditioning (Trickle Charge) Thermal Loop Current Reduction in C.C. Mode No Yes Yes Recharge Test VRCH > V BAT Yes Current Phase Test VIN > VBAT_EOC Yes Constant Current Charge Mode Device Thermal Loop Monitor TJ > 115°C USBCH = USB, ADPCH = ADP No No VADPCH > VUVLO_ADPCH (3.5V) Voltage Phase Test IBAT > ITERM Yes Yes Constant Voltage Charge Mode No No Charge Completed No VUSBCH > VUVLO_USBCH (3.5V) Yes USB Charge Preconditioning Test VMIN > VBAT No Yes Preconditioning (Trickle Charge) Auto Charge Reduction Loop Control No Yes Recharge Test VRCH > VBAT Yes Current Phase Test VIN > VBAT_EOC Yes Constant Current Charge Mode VUSBCH < 4.5V No No Voltage Phase Test IBAT > ITERM Yes Constant Voltage Charge Mode No Charge Completed Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 201894B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 27, 2012 11 DATA SHEET AAT3691 Dual Input 1.6A Linear Charger with 28V OVP in a 3x4 TDFN Package Application Information ICH_CC (mA) 50 75 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 Charge Sources The AAT3691 operates from sources of an adapter or USB interface. The internal system control will always select the adapter input to charge the battery rather than the USB input if the adapter voltage is above 4.5V. The normal charging input voltage range is up to typical 6.75V. The device can withstand up to 28V on the adapter or USB inputs without damage to the IC. If VADP or VUSB is greater than 6.75V, the internal over-voltage protection circuitry disables charging until the input falls below typical 6.55V. AC Adapter/USB System Power Charging Adapter Mode In the adapter mode, constant current charge levels up to 1.6A can be programmed by the user. The fast charge current for the adapter input mode is set by the RADPSET resistor connected between ADPSET and ground. It is programmed by the following equations: IADP_CC = 2 · KIADPSET RADPSET RADPSET = 2 · KIADPSET IADP_CC with KIADPSET = 800. Table 1 gives the recommended 1% tolerance metal film resistance values for a desired constant current charge level. The initial thermal loop current can be estimated by the following equation: ITLOOP = ICC · 0.44 12 RUSBSET (kΩ) 16 8.06 5.36 4.02 3.24 2.67 2.32 2 1.78 1.60 1.47 1.33 1.24 1.15 1.07 1 32.4 21.5 16 8.06 5.36 4.02 3.24 Table 1: Standard 1% Metal Film Resistor Values for Constant Current Setting. The thermal loop control re-evaluates the circuit die temperature every three seconds and raises the fast charge current in small steps to the full fast charge current level. Figure 2 illustrates the thermal loop function at 1A fast charge current as the ambient temperature increases and recovers. In this manner the thermal loop controls the system charge level, and the AAT3691 provides the highest level of constant current in the fast charge mode for any possible valid ambient temperature condition. 1.6 Thermal Loop Control 1.4 Ambient Temperature increases Charge Current (0.2A/div) To protect the linear charging IC from thermal problems, a special thermal loop control system is used to maximize charging current under adapter charge mode. The thermal management system measures the internal circuit die temperature and reduces the fast charge current when the die exceeds the preset internal temperature control threshold. Once the thermal loop control becomes active, the fast charge current is initially reduced by a factor of 0.44. RADPSET (kΩ) 1.2 1.0 0.8 0.6 0.4 Ambient Temperature decreases 0.2 0.0 Time (10s/div) Figure 2: Digital Thermal Loop Function at 1A Fast Charge Current with Ambient Temperature Increasing and Recovering. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 201894B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 27, 2012 DATA SHEET AAT3691 Dual Input 1.6A Linear Charger with 28V OVP in a 3x4 TDFN Package Adapter Input Charge Inhabit and Resume USB Input Charge Inhibit and Resume The AAT3691 has an under-voltage lockout feature so that if the charger input supply ADP pin drops below the UVLO threshold, the charger will suspend charging. When the UVLO condition is removed and VADPCH > VBAT, the system charge control assesses the state of charge of the battery cell and automatically resumes charging in the appropriate phase (pre-conditioning trickle charge, constant current charge, constant voltage charge or end of charge) according to the condition of the battery. The AAT3691 UVLO and power on reset feature functions when the USB input pin voltage level drops below the UVLO threshold. At this point, the charger suspends charging and shuts down. When power is re-applied to the USB pin or the UVLO condition recovers, the system charge control will assess the state of charge on the battery cell and automatically resume charging in the appropriate mode for the condition of the battery. Enable / Disable USB Mode The AAT3691 also provides an input for intelligent USB charging. When no voltage is present on the adapter input pin or adapter input is below 4.5V, the charge controller will automatically switch to accepting power from the USB input. The USB charge may be user programmed to any level between 50mA and 500mA by selecting the appropriate resistor values for RUSBSET. IUSB_CC = 2 · KIUSBSET RUSBSET RUSBSET = 2 · KIUSBSET IUSB_CC Among them, KIUSBSET is 800. Refer to Table 1 for recommended RUSBSET values for the desired USB input constant current charge levels. USB Charge Reduction In many instances, product system designers do not know the real properties of a potential USB port used to supply power to the battery charger. Typically, powered USB ports found on desktop and notebook PCs should supply up to 500mA. If a USB port being used to supply the charger is unable to provide the programmed fast charge current or if the system under charge must share supply current with other functions, the AAT3691 automatically reduces USB fast charge current to maintain port integrity and protect the host system. The USB charge reduction system becomes active when the voltage on the USBCH input falls below the USB charge reduction threshold, typically 4.5V. The charge reduction system reduces the fast charge current level in a linear fashion until the voltage sensed on the USB input recovers above the charge reduction threshold voltage. The AAT3691 provides an enable function to allow the normal operating input voltage to pass through and control the IC charging. The Enable (EN) pin is active low and is pulled down to ground by an internal 200kΩ resistor. When pulled to a logic high level, the AAT3691 is shut down and forced into the sleep state during which input voltage up to 28V will be blocked and charging be halted regardless of the battery voltage or charging state. When the device is re-enabled, the OVP block will automatically reassess the input voltage and allow the normal operating voltage to pass through. If a battery is also present (NOBAT is low), the charge control circuit will automatically reset and resume charging with the appropriate charging mode based on the battery charge state and measured cell voltage. Over-Temperature Shutdown Thermal protection completely disables charging when internal dissipation exceeds the junction over-temperature threshold, which is 140°C with 15°C of hysteresis. Once the over-temperature fault condition is removed, the charge function automatically recovers. Battery Charge Status Indication The AAT3691 has one status LED driver output. The LED can indicate simple functions such as battery charging, charge complete, and charge disabled. Description EN LED Status Battery charging Charge complete Charge disabled low low high on off off Table 2. LED Status Conditions. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 201894B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 27, 2012 13 DATA SHEET AAT3691 Dual Input 1.6A Linear Charger with 28V OVP in a 3x4 TDFN Package Output Capacitor The LED anodes should be connected to either VUSBCH or VADPCH, depending upon the system design requirements. The LEDs should be biased with as little current as necessary to create reasonable illumination; therefore, a ballast resistor should be adopted to limit the current flowing through the LED by connecting it with the LED in series between STAT and VUSBCH or VADPCH. LED current consumption will add to the overall thermal power budget for the device package, so LED drive current should be kept to a minimum. 2mA should be sufficient to drive most low-cost green or red LEDs. It is not recommended to exceed 8mA for driving an individual status LED. The required ballast resistor value can be estimated using the following formulas: The AAT3691 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. In a fast charge application with current above 1A, a 22μF output capacitor is required to obtain an accurate recharge voltage threshold. If the AAT3691 is used in applications where the battery can be removed from the charger, such as in the case of desktop charging cradles, an output capacitor value greater than 10μF may be required to prevent the device from cycling on and off when no battery is present. To connect to ADPCH: Thermal Considerations R= VADPCH - VFLED ILED To connect to USBCH: R= VUSBCH - VFLED ILED For example, using a red LED with 2.0V VF @ 2mA, calculate R under 5.5V VADPCH: R= 5.5V - 2.0V = 1.75kΩ 2mA Capacitor Selection Input Capacitor An input capacitor is used to filter the input voltage by placing a decoupling capacitor between the ADP, ADPCH, USB and USBCH pins and ground. An input capacitor in the range of 1μF to 10μF 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. This input capacitor range is also suitable for a system with an external power supply source, such as a typical AC-to-DC wall adapter. It will minimize switching or power bounce effects when the power supply is “hot plugged”. Likewise, a 2.2μF 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. 14 The actual maximum charging current is a function of the charge input voltage (USBCH and ADPCH), the battery voltage at the BAT pin, the ambient temperature, the rising temperature when charge current passing through the RDS(ON) of the charging pass, and the thermal impedance of the package. The maximum programmable current may not be achievable under all operating parameters. The AAT3691 is offered in a 3x4mm TDFN package which can provide up to 2.0W of power dissipation when properly soldered 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 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: PD = [(VIN - VBAT) · ICC + (VIN · IOP)] Where: PD = Total power dissipation of the AAT3691 VIN = VADP or VUSB, depending on which mode is selected VBAT = Battery voltage at the BAT pin ICC = Maximum constant fast charge current programmed for the application IOP = Quiescent current consumed by the charger IC for normal operation. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 201894B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 27, 2012 DATA SHEET AAT3691 Dual Input 1.6A Linear Charger with 28V OVP in a 3x4 TDFN Package Next, the maximum operating ambient temperature for a given application can be estimated based on the thermal resistance of the 3x4 TDFN package when sufficiently mounted to a PCB layout and the internal thermal loop temperature threshold. TA = TJ - (θJA · PD) Where: The device power dissipation for the stated condition can be calculated as below: PD = (5.0 – 3.6V) · 1A + (5.0V · 0.25mA) ≈ 1.4W The maximum ambient temperature is TA = 110°C - (50°C/W · 1.4W) = 40°C TA = Ambient temperature in °C TJ = Maximum device junction temperature below the thermal loop threshold PD = Total power dissipation by the device θJA = Package thermal resistance in °C/W. Therefore, under the stated conditions for this worst case power dissipation example, the AAT3691 will enter the digital thermal loop and lower the fast charge constant current when the ambient operating temperature rises above 40°C. Example: Printed Circuit Board Layout Considerations For an application where the fast charge current for the adapter mode is set to 1A, VADP = 5.0V, and the worst case battery voltage is 3.6V, what is the maximum ambient temperature at which the digital thermal loop limiting will become active? Given: VADP = 5.0V VBAT = 3.6V ICC = 1A IOP = 0.25mA TJ = 110°C θJA = 50°C/W For the best results, it is recommended to physically place the battery pack as close to the AAT3691 BAT pin as possible. To minimize voltage drops on the PCB, keep the high current carrying traces adequately wide. For maximum power dissipation of the AAT3691 TDFN package, the exposed pad should be soldered to the board ground plane to further increase local heat dissipation. A ground pad below the exposed pad is strongly recommended. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 201894B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 27, 2012 15 DATA SHEET AAT3691 Dual Input 1.6A Linear Charger with 28V OVP in a 3x4 TDFN Package USB C11 1μF/50V U1 AAT3691 USBCH USB C12 2.2μF/10V USBCH ADP C21 1μF/50V BAT 16 2 USBCH N/C 15 3 ADP ADPCH 4 LED1 Red J2 14 ADPCH USBSET 13 R2 5 IC ADPSET 12 R3 6 STAT EN 11 7 IC IC 10 8 GND GND 9 EP BAT BAT NOBAT 1.74k C22 2.2μF/10V ADPCH USBCH USB ADP R1 ADPCH 1 C3 10μF Disable J1 3 1 2 Figure 3: AAT3691 Evaluation Board Schematic. 16 Figure 4: AAT3691 Evaluation Board Figure 5: AAT3691 Evaluation Board Top Side Layout. Bottom Side Layout. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 201894B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 27, 2012 DATA SHEET AAT3691 Dual Input 1.6A Linear Charger with 28V OVP in a 3x4 TDFN Package Component Part Number Description Manufacturer U1 R1 R2 R3 C3 C11, C21 C12, C22 J1 J2, Disable LED1 ADP, USB, BAT ADPCH, USBCH G1, G2 AAT3691IRN-T1 RC0603FR-071K74L RC0603FR-073K24L RC0603FR-072KL GRM188R60J106M GRM21BR71H105K GRM188R61A225K TMM-103-03-T-S TMM-102-03-T-S 0805KRCT DG308-2.54-02-14 5010K-ND 5011K-ND 0.5A USB Port /1.6A Adapter Lithium-lon; 16-Pin 3x4 TDFN Package Res 1.74KΩ 1/10W 1% 0603 SMD Res 3.24KΩ 1/10W 1% 0603 SMD Res 1.6KΩ 1/10W 1% 0603 SMD Cap Ceramic 10μF 0603 X5R 6.3V 20% Cap Ceramic 1μF 0805 X7R 50V 10% Cap Ceramic 2.2μF 0603 X5R 10V 10% Conn. 3-pin header, 2.54mm Pitch Conn. 2-pin header, 2.54mm Pitch Red LED; 0805 Multi-position micro PCB terminal blocks, 2.54mm, 2 pin, Green Red Test point Black Test point Skyworks Yageo Yageo Yageo Murata Murata Murata Samtec Samtec HB Degson Keystone Keystone Table 3: AAT3691 Evaluation Board Bill of Materials. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 201894B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 27, 2012 17 DATA SHEET AAT3691 Dual Input 1.6A Linear Charger with 28V OVP in a 3x4 TDFN Package Ordering Information Package NOBAT Input EOC Voltage Marking1 Part Number (Tape and Reel)2 TDFN34-16 Active high 4.2 4TXYY AAT3691IRN-4.2-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. Package Information TDFN34-163 3.000 ± 0.050 0.450 ± 0.050 1.600 ± 0.050 Detail "A" 0.230 ± 0.050 0.450 ± 0.050 3.300 ± 0.050 4.000 ± 0.050 Index Area Top View Bottom View 0.750 ± 0.050 Detail "A" 0.000 + 0.100 -0.000 0.203 REF Side View All dimensions in millimeters. 1. XYY = assembly and date code. 2. Sample stock is generally held on part numbers listed in BOLD. 3. The leadless package family, which includes QFN, TQFN, DFN, TDFN and STDFN, has exposed copper (unplated) at the end of the lead terminals due to the manufacturing process. A solder fillet at the exposed copper edge cannot be guaranteed and is not required to ensure a proper bottom solder connection. Copyright © 2012 Skyworks Solutions, Inc. All Rights Reserved. Information in this document is provided in connection with Skyworks Solutions, Inc. (“Skyworks”) products or services. These materials, including the information contained herein, are provided by Skyworks as a service to its customers and may be used for informational purposes only by the customer. Skyworks assumes no responsibility for errors or omissions in these materials or the information contained herein. Skyworks may change its documentation, products, services, specifications or product descriptions at any time, without notice. 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Additional information, including relevant terms and conditions, posted at www.skyworksinc.com, are incorporated by reference. 18 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 201894B • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • April 27, 2012