PRODUCT DATASHEET AAT3691 BatteryManagerTM Dual Input 1.6A Linear Charger with 28V OVP in 3x4 TDFN General Description Features The AAT3691 BatteryManagerTM 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 Trickle Charge for Battery Preconditioning * Thermal Shutdown Protection * Power On Reset and Soft Start * Active Low Enable with Internal 200k 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 -40C to +85C 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 1F 10F USBCH IC BATT- 2.2F AAT3691 Voltage Source NOBAT NOBAT R STAT ADPIN 1F 3691.2009.03.1.1 2.2F EN ADP USBSET ADPCH ADPSET GND www.analogictech.com ON/OFF RADPSET RUSBSET 1 PRODUCT DATASHEET AAT3691 BatteryManagerTM Dual Input 1.6A Linear Charger with 28V OVP in 3x4 TDFN 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 2.2F capacitor. Input from adapter port connector Output from ADP OVP stage, input to battery charger. Decouple with 2.2F capacitor. Internally used. Connect to GND or leave floating. Charge status indication pin, open drain. Connect to power ground Active low enable with internal 200k 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 1.6M 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 www.analogictech.com 3691.2009.03.1.1 PRODUCT DATASHEET AAT3691 BatteryManagerTM Dual Input 1.6A Linear Charger with 28V OVP in 3x4 TDFN 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. 3691.2009.03.1.1 www.analogictech.com 3 PRODUCT DATASHEET AAT3691 BatteryManagerTM Dual Input 1.6A Linear Charger with 28V OVP in 3x4 TDFN Electrical Characteristics1 VADP = VUSB = 5V, TA = -25C to +85C, unless otherwise noted. Typical values are at TA = 25C. Symbol Description Conditions 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 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 A A A 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 = 25C 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 -40C to +85C operating temperature range and are assured by design, characterization and correlation with statistical process controls. 4 www.analogictech.com 3691.2009.03.1.1 PRODUCT DATASHEET AAT3691 BatteryManagerTM Dual Input 1.6A Linear Charger with 28V OVP in 3x4 TDFN Electrical Characteristics (continued)1 VADP = VUSB = 5V, TA = -25C to +85C, unless otherwise noted. Typical values are at TA = 25C. Symbol Description Conditions 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 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 = 1F VADP voltage step up signal from 0V to 5V, RLOAD = 10, CADPCH = 1F RLOAD = 10, CADPCH = 1F Thermal Shutdown Threshold Hysteresis 0.5 1.0 Units V V V mA V V V s 5 s 130 s 100 140 15 s C 1. The AAT3691 is guaranteed to meet performance specifications over the -40C to +85C operating temperature range and are assured by design, characterization and correlation with statistical process controls. 3691.2009.03.1.1 www.analogictech.com 5 PRODUCT DATASHEET AAT3691 BatteryManagerTM Dual Input 1.6A Linear Charger with 28V OVP in 3x4 TDFN Typical Characteristics Over-Voltage Protection vs. Temperature End of Charge Voltage vs. Supply Voltage (RADPSET = 1k, RUSBSET = 3.2k) 4.22 6.80 4.21 6.70 6.65 VEOC (V) VADP or VUSB (V) 6.75 Power sweep low to high Power sweep high to low 6.60 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 (k) 100 RUSBSET (k) Battery Recharge Voltage Threshold vs. Supply Voltage Battery Recharge Voltage Threshold vs. Temperature (RADPSET = 1k; RUSBSET = 3.2k; CBAT = 22F) (VADP = VUSB = 5V; RADPSET = 1k; RUSBSET = 3.2k; CBAT = 22F) 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 6.1 6.5 4.02 4.00 -40 VADP or VUSB (V) 6 USB ADP -20 0 20 40 60 80 Temperature (C) www.analogictech.com 3691.2009.03.1.1 PRODUCT DATASHEET AAT3691 BatteryManagerTM Dual Input 1.6A Linear Charger with 28V OVP in 3x4 TDFN Typical Characteristics End of Charge Voltage vs. Temperature Charge Current vs. Temperature (RADPSET = 1k; RUSBSET = 3.2k) (VADP = VUSB = 5V; VBAT = 3.6V; RADPSET = 1k; RUSBSET = 3.2k) 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 = 1k; RUSBSET = 3.2k) (RUSBSET = 3.2k) 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 = 1k) (RUSBSET = 3.2k) 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 6.0 6.4 400 300 100 6.8 VADP (V) 3691.2009.03.1.1 -40C 0C 25C 50C 85C 200 0 4.0 4.4 4.8 5.2 5.6 6.0 6.4 6.8 VUSB (V) www.analogictech.com 7 PRODUCT DATASHEET AAT3691 BatteryManagerTM Dual Input 1.6A Linear Charger with 28V OVP in 3x4 TDFN Typical Characteristics ADP Charging Current vs. Battery Voltage USB Charging Current vs. Battery Voltage (VADP = 5V) (VUSB = 5V) 1800 600 RSET = 1k RSET = 1.14k RSET = 1.33k RSET = 1.6k RSET = 2k RSET = 3.2k RSET = 5.33k RSET = 16k 1200 900 600 500 ICH_USB (mA) ICH_ADP (mA) 1500 300 RSET = 3.2k RSET = 4k RSET = 5.33k RSET = 8k RSET = 16k RSET = 32k 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 NOBAT VIL (V) NOBAT VIH (V) 0.65 1.10 1.05 1.00 0.95 0.90 -40C 25C 85C 0.85 3.6 4.2 4.8 5.4 6.0 0.60 0.55 0.50 -40C 25C 85C 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 -40C 25C 85C 0.85 4.8 5.2 5.6 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 6.0 6.4 0.65 0.60 0.55 0.50 -40C 25C 85C 0.45 0.40 4.0 VUSB or VADP (V) 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) 4.4 4.8 5.2 5.6 6.0 6.4 VUSB or VADP (V) www.analogictech.com 3691.2009.03.1.1 PRODUCT DATASHEET AAT3691 BatteryManagerTM Dual Input 1.6A Linear Charger with 28V OVP in 3x4 TDFN 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. 3691.2009.03.1.1 During adapter charging, high set charging current or high ambient operating temperature may cause the AAT3691 junction temperature to rise up to 110C. 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 140C with 15C 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. www.analogictech.com 9 PRODUCT DATASHEET AAT3691 BatteryManagerTM Dual Input 1.6A Linear Charger with 28V OVP in 3x4 TDFN 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 130s typical internal delay; if VUSB/ADP rises above 6.75V (typical), the OVP switch is turned off after a 0.5s typical internal delay. www.analogictech.com 3691.2009.03.1.1 PRODUCT DATASHEET AAT3691 BatteryManagerTM Dual Input 1.6A Linear Charger with 28V OVP in 3x4 TDFN System Operation Flowchart Power On Reset OVP Switch Off Yes NOBAT Indicates No Battery No Enable Adapter Charge No Yes USBCH = ADPCH = 0V No 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 USBCH = USB, ADPCH = ADP Device Thermal Loop Monitor TJ > 115C 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 3691.2009.03.1.1 www.analogictech.com 11 PRODUCT DATASHEET AAT3691 BatteryManagerTM Dual Input 1.6A Linear Charger with 28V OVP in 3x4 TDFN 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. 32.4 21.5 16 8.06 5.36 4.02 3.24 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 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 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. 1.2 1.0 0.8 0.6 0.4 Ambient Temperature decreases 0.2 0.0 Time (10s/div) The initial thermal loop current can be estimated by the following equation: 12 RUSBSET (k) Table 1: Standard 1% Metal Film Resistor Values for Constant Current Setting. Thermal Loop Control ITLOOP = ICC * 0.44 RADPSET (k) Figure 2: Digital Thermal Loop Function at 1A Fast Charge Current with Ambient Temperature Increasing and Recovering. www.analogictech.com 3691.2009.03.1.1 PRODUCT DATASHEET AAT3691 BatteryManagerTM Dual Input 1.6A Linear Charger with 28V OVP in 3x4 TDFN 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. 3691.2009.03.1.1 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 200k 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 140C with 15C 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 www.analogictech.com Table 2. LED Status Conditions. 13 PRODUCT DATASHEET AAT3691 BatteryManagerTM Dual Input 1.6A Linear Charger with 28V OVP in 3x4 TDFN 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 1F ceramic capacitor on the BAT pin to maintain circuit stability. This value should be increased to 10F or more if the battery connection is made any distance from the charger output. In a fast charge application with current above 1A, a 22F 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 10F 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 = 1.75k 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 1F to 10F 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 2.2F 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 50C/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. www.analogictech.com 3691.2009.03.1.1 PRODUCT DATASHEET AAT3691 BatteryManagerTM Dual Input 1.6A Linear Charger with 28V OVP in 3x4 TDFN 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. 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 = TJ - (JA * PD) TA = 110C - (50C/W * 1.4W) = 40C Where: TA = Ambient temperature in C TJ = Maximum device junction temperature below the thermal loop threshold PD = Total power dissipation by the device JA = 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 40C. 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 = 110C JA = 50C/W 3691.2009.03.1.1 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. www.analogictech.com 15 PRODUCT DATASHEET AAT3691 BatteryManagerTM Dual Input 1.6A Linear Charger with 28V OVP in 3x4 TDFN USB C11 1F/50V U1 AAT3691 USBCH USB C12 2.2F/10V USBCH ADP C21 1F/50V C22 2.2F/10V ADPCH USBCH USB BAT 16 2 USBCH N/C 15 ADP 3 ADP ADPCH 4 R1 ADPCH 1 LED1 Red J2 NOBAT 14 ADPCH USBSET 13 R2 5 IC ADPSET 12 R3 6 STAT EN 11 7 IC IC 10 8 GND GND 9 1.74k EP BAT BAT C3 10F Disable J1 3 1 2 Figure 3: AAT3691 Evaluation Board Schematic. Figure 4: AAT3691 Evaluation Board Top Side Layout. 16 www.analogictech.com Figure 5: AAT3691 Evaluation Board Bottom Side Layout. 3691.2009.03.1.1 PRODUCT DATASHEET AAT3691 BatteryManagerTM Dual Input 1.6A Linear Charger with 28V OVP in 3x4 TDFN 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 1.74K 1/10W 1% 0603 SMD Res 3.24K 1/10W 1% 0603 SMD Res 1.6K 1/10W 1% 0603 SMD Cap Ceramic 10F 0603 X5R 6.3V 20% Cap Ceramic 1F 0805 X7R 50V 10% Cap Ceramic 2.2F 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 AnalogicTech Yageo Yageo Yageo Murata Murata Murata Samtec Samtec HB Degson Keystone Keystone Table 3: AAT3691 Evaluation Board Bill of Materials. 3691.2009.03.1.1 www.analogictech.com 17 PRODUCT DATASHEET AAT3691 BatteryManagerTM Dual Input 1.6A Linear Charger with 28V OVP in 3x4 TDFN 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 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/about/quality.aspx. 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. Advanced Analogic Technologies, Inc. 3230 Scott Boulevard, Santa Clara, CA 95054 Phone (408) 737-4600 Fax (408) 737-4611 (c) Advanced Analogic Technologies, Inc. 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. Except as provided in AnalogicTech's terms and conditions of sale, AnalogicTech assumes no liability whatsoever, and AnalogicTech disclaims any express or implied warranty relating to the sale and/or use of AnalogicTech products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. In order to minimize risks associated with the customer's applications, adequate design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards. 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. 18 www.analogictech.com 3691.2009.03.1.1