SC806 Miniature High Current Lithium-Ion Battery Charger POWER MANAGEMENT Description Features Fully integrated charger with FET pass transistor, The SC806 is a fully integrated, single cell, constant-current (cc)/constant-voltage (cv) Lithium-Ion battery charger in a tiny 3x3 mm thermally enhanced MLP package. The SC806 can operate as a stand-alone charger or in conjunction with a Power Management Controller (PMIC). The SC806 has a pre-charge function for trickle charging deeply discharged batteries. The fast charge current is enabled automatically when the battery voltage reaches the required threshold. When the battery reaches the constant voltage or CV portion of the charge curve the SC806 switches to CV regulation mode. In this mode the output current decays until the termination current is reached. At this point the SC806 signals the charge cycle is complete and turns off the output and enters the monitor mode. If the battery voltage drops by 100mV from the CV voltage a new charge cycle will begin. The SC806 can also function as a general purpose cur- rent source or as a current source for charging NickelCadmium (NiCd) and Nickel-Metal-Hydride (NiMH) batteries. reverse-blocking diode, sense resistor and thermal protection High Accuracy Charge Current* Tiny 3mm x 3mm 10 lead MLP package Programmable precharge, fastcharge and termination current Battery voltage controlled to 1% accuracy Battery Charge Current accurate to 5% at 800mA Soft-start for step load and adapter plug-in Up to 1A continuous charge current Input voltage range from 3V to 6V allows seamless charging from current limited adapter 0.1µA battery drain current in shutdown and monitor modes Over current protection in all charging modes Automatic loss of battery detection Adapter Present, Charge Status, and No Battery output LED drivers *Patent Pending Applications Typical Application Circuit Cellular phones PDAs Handheld meters Charging stations USB chargers Digital cameras GPS Handhelds Programmable current source SC806 Typical Application Circuit NTC Voltage SC806 3 10 2 8 7 CHARGER VIN D2 C1 .1uF LED D1 VCC VOUT CHRGB NTC CPB ITERM NOBAT IPRGM DIS GND 1 9 5 4 6 LED R2 1k R1 1k BATTERY R4 3.01k NOBAT Indicator Adapter Present Indicator R3 3.01k C2 2.2uF Charging Indicator August 10, 2005 1 www.semtech.com SC806 POWER MANAGEMENT Absolute Maximum Ratings Exceeding the specifications below may result in permanent damage to the device or device malfunction. Operation outside of the parameters specified in the Electrical Characteristics section is not implied. Parameter Symbol Maximum Units VCC, CPB, CHRGB, N TC, DIS to GN D -0.3 to 7.0 V VOUT, N OBAT, IPRGM, ITERM to GN D -0.3 to +6.0 V Power Dissipation MLP (Derate 20mW/°C above 85°C) Pd 2 W Thermal Impedance, Junction to Case θ JA 50* °C/W Tjmax 150 °C TA -40 to +85 °C Peak IR Reflow temperature, soldering 20s-40s T LE A D 260 °C Storage Temperature Range TSTG -65 to 150 °C Continuous A 1 A Junction Temperature Operating Ambient Temperature Range VOUT shor t to GN D VOUT Output Current *Calculated from package in still air, mounted to 3” x 4.5”, 4 layer FR4 PCP with thermal vias under the exposed pad per JESD51 standards. Electrical Characteristics Unless otherwise noted: VCC = 4.75V - 5.25V. Parameter Symbol Conditions 25oC Min Input Voltage VC C Typ TA (-40oC to +85°C) Units Max Min Max 5 3.15 6.3 V ICCDIS Shutdown Mode DIS = 5V 850 400 1200 µA ICCCHG Charging Mode, CPB, CHRGB, ITERM, IPRGM = 0 µA 1.2 0.8 2.25 mA Battery Leakage Current IleakBAT V C C = 0V 0.1 1 µA Regulated Voltage VBAT** V Battery Pre-Charge Current IPREQ Operating Current 4.2 4.16 4.24 50 45 55 ITERM Resistor R = 3.01k Battery Termination Current Battery Fast-Charge Current ITERMQ IFastQ1 IFastQ2 Battery Fast-Charge Current Limit 2004 Semtech Corp. IPRGM = 15k IPRGM = 1.87k VBATTERY = 3.8V 2.8V < VBATTERY < VBAT Dropout Voltage = 1V 2 mA 50 45 55 100 91.5 111.5 mA 787 -5 +5 % 1.0*** A www.semtech.com SC806 POWER MANAGEMENT Electrical Characteristics (Cont.) Unless otherwise noted: VCC = 4.75V - 5.25V. Parameter Symbol Conditions 25oC Min Typ TA (-40oC to +85oC) Max Min Max Units Iprog Regulated Voltage VIPRGM 1.5 1.4 1.6 V Iterm Regulated Voltage VITERM 1.5 1.4 1.6 V Vin UVLO Rising Threshold VTUVLOR 2.8 2.65 3.15 V Vin UVLO Falling Threshold VTUVLOF 2.75 2.60 3.10 V Vin UVLO Hysteresis VTUVLOH Vin OVP Rising Threshold VTOVPOR 6.8 6.3 7.5 V Vin OVP Falling Threshold VTOVPOF 6.4 5.9 7.15 V Vin OVP Hysteresis VTOVPOH 400 150 600 mV Vbat Precharge Threshold VTPREQR 2.8 2.7 2.9 V Vbat Recharge Threshold VTREQ VBAT - VBATTERY VTNOBAT No Battery Detect Tested at Vcc=5V 95 93 96 %Vcc VTDIS VCC=5V 1.0 0.4 1.25 V OT Hysteresis = 10°C 150 VCBVOL Charging Isnk=2mA 0.2 .5 V ICBOFF Charge Complete, Disable or UV off leakage .1 1 µA VCPVOL Charger Present Isnk=2mA 0.2 .5 V ICPOFF UV off leakage .1 1 µA VNBVOH NTC=VCC, Isrc=1mA 4.8 INBOFF NTC=VCC/2 off leakage .1 NTC Thresholds DIS Threshold Over Temperature Shutdown CHRGB LED output CPB LED output NoBat output 20 60 50 100 mV 140 mV C ° 4.5 V 1 µA Notes: * Tied to PCB with 1 Square Inch, 2 Ounce Copper. Tja=41°C/W using JESD 51 Standard. ** Iload=75mA. See typical performance curve for load regulation characteristics. *** Thermally Limited. 2004 Semtech Corp. 3 www.semtech.com SC806 POWER MANAGEMENT Pin Configuration Ordering Information Device Top View VOUT 1 10 CHRGB CPB 2 9 NTC VCC 3 8 NOBAT IPRGM 4 7 DIS ITERM 5 6 GND (1) P ackag e SC806IMLTRT(2) MLP-10 S C 806E V B Evaluation Board Note: (1) Only available in tape and reel packaging. A reel contains 3,000 devices. (2) Available in lead-free packaging only. This product is fully WEEE and RoHS compliant. MLP10: 3x3 10 Lead Pin Descriptions Pin # Pin Name 1 VOUT 2 C PB Output status indicator for the adapter present. This output is active low when the VCC input voltage is above the UVLO threshold. 3 VC C Supply pin, connect to adaptor power. 4 IPRGM Charger current limit program pin. Requires a resistor to ground to program fast-charge current. 5 ITERM Selection for current termination and pre-charge current. Requires a resistor to ground to program pre-charge and termination current. 6 GND Ground. 7 DIS Device disable/enable pin. This pin is active low to enable the SC806, a high level disables operation. 8 NOBAT Output status indicator for 'No Battery' condition. Output is active high when the battery is removed. Output is high impedance when the battery is present. 9 NTC This pin is used to detect the NTC element inside the battery pack by detecting a voltage within 95% of VCC. Connect to resistor pullup to VCC and NTC to ground. This pin only controls the NOBAT output and does not effect the charger output. 10 CHRGB 2004 Semtech Corp. Pin Function Charger output, connect to battery. Output status indicator. Active low output indicates charger is delivering current to the battery. CHRGB output goes high impedance when the output current falls below the termination current setting and the output is turned off. Connect cathode of the 'charging' LED this pin to indicate charge in progress. 4 www.semtech.com SC806 POWER MANAGEMENT Block Diagram VCC 3 Reference Voltages Vout Ref Fast Charge Ref Pre-Charge Ref GND 6 CPB Control 2 Pre-Charge On Fast-Charge On VOUT Over Temp NOBAT 1 Under Voltage 8 Over Voltage DIS 7 NTC Interface IPRGM NTC 4 9 CHRGB 10 Fast Charge Ref ITERM VOUT 5 Vout Ref Pre-Charge Ref SC806 6V Charger Block Diagram 2004 Semtech Corp. 5 www.semtech.com SC806 POWER MANAGEMENT General Operation The SC806 is configured based on the application for Fast Charge and Termination current. A typical charging cycle is described below. Details on alternate applications and output programmability are covered in the individual sections. Note that for a given program resistor the current through the battery in CV mode can be determined by replacing 1.5 with the actual voltage on the IPRGM pin in the above equation. Termination Current Once the battery reaches the program voltage of 4.2V the device will transition from a constant current source to a constant voltage source and the current through the battery begins to decrease while the voltage remains constant. When the current falls below the programmed termination current set by the termination resistor on the ITERM pin, the SC806 will transition the CHRGB pin from low to high. The equation to set the termination current is given by: The charging cycle begins when the adapter is plugged in. The SC806 performs glitch filtering on the VCC input and initiates a charge cycle when VCC > UVLO. At this time, the CHRGB and CPB signals are active low turning on the LEDs. If the battery voltage is less than 2.8V, the SC806 will charge the output with the pre-charge current. When the battery voltage exceeds 2.8V, the SC806 enters fast-charge or constant current (CC) mode. When the battery voltage reaches its final value, the charger enters the constant voltage (CV) mode. In this mode the output voltage is held constant and the current decreases until the termination current level is reached. 1.5 • 100 ITERM = R TERM At this point the charger enters monitor mode and the CHRGB output is high impedance. The charger output remains off in monitor mode until Vout drops by 100mV and a new charge cycle is initiated. Monitor Mode When a charge cycle is completed, the SC806 output turns off and the device enters monitor mode. If the voltage of the battery falls below the recharge threshold of 4.1V the charger will re-initiate a charge cycle. The maximum current drain of the battery during monitor mode will be no more than 1µA over temperature Pre-Charge Mode Pre-charge mode is automatically enabled whenever the battery voltage is below 2.8V. It is used to limit the power dissipation and precondition the battery for fast charging. The pre-charge current value is selected by the resistor on the ITERM pin. The pre-charge current is programmable from 10mA to 125mA. The equation to select the pre-charge current is given by: 1.5 PCI = R TERM NTC Input/NOBAT output The SC806 detects the absence of the battery by monitoring the voltage on the NTC pin. When the NTC pin voltage exceeds 90% of VCC the NOBAT output is driven high. This function utilizes the standard NTC configuration with the NTC component residing in the battery pack. When the battery is removed the NTC element in the resistor divider is missing and the NTC voltage is pulled up to VCC. • 100 Fast-Charge Mode (CC) The fast-charge or CC mode is active when the battery voltage is above 2.8V and less than the 4.2V CV voltage of the battery. The fast-charge current can be set to a maximum of 1.0A and is selected by the program resistor on the IPRGM pin. The voltage on this pin will represent the current through the battery enabling a microprocessor to monitor battery current by sensing the voltage on the IPRGM pin. The equation to set the fastcharge current is given by: The NOBAT output can be used to signal the system that the battery has been removed or drive an external LED. DIS Device Disable Interface The DIS pin on the SC806 is used to shutdown the SC806 charger. This pin must be pulled low to enable the charger, high will disable the charger (do not leave floating). The CPB output indicating the adapter input status is active regardless of the state of DIS. 1.5 • 1000 FCI = R PRGM 2004 Semtech Corp. 6 www.semtech.com SC806 POWER MANAGEMENT CHRGB LED Flag The CHRGB LED driver on the SC806 can be used to drive an LED and/or signal the system processor. CHRGB=Low (Charging) and CHRGB=High-Z (Charge Complete). The CHRGB output will be high impedance when the VCC is in a UV condition. The Table below defines the CHRGB LED output states. CPB LED Flag The CPB LED driver on the SC806 is used to indicate that the adapter voltage is present at the input to the SC806. The CPB output is an active low output when the input voltage is greater than 3V. This feature is active regardless of the state of the DIS pin. LED Low High-Z Blinking Layout Guidelines CHRGB Iout > term Iout < term OV or OT Fault The two most critical aspects of the pcb layout are the power path and thermal layout. The power path starts at the Adapter + input and runs to the VCC input of the SC806, then from the Vout pin of the SC806 to the Battery + terminal, and completes with the return trace from the battery - terminal to the adapter - input. All of these traces need to be designed to handle the required charging current. The trace from Vout of the SC806 is most critical and should be made as wide as possible to minimze IR drops between the regulated voltage at the SC806 vout pin and the battery terminal. Keep the Adapter+ to SC806 VCC input trace wide to minimize voltage drops that will add to the dropout voltage capability of the SC806. The GND pin of the SC806 should be connected in a kelvin fashion at the Battery terminal to eliminate voltage drops in the return path reducing the regulated battery voltage. The CHRGB output signifies the charging status. When the output current is > Itermination, CHRGB=low. CHRGB is high impedance when Iout is < Itermination. The CHRGB output is latched high-Z at the end of the charge cycle when the output current is less than Itermination. The CHRGB output will remain high until the battery enters a recharge cycle, or if EN, or VCC are toggled. . There are three fault modes detected by the SC806; (Input under voltage, input over voltage, and Max die temperature or OT). The LED states for these fault modes are shown below. Fault CHR GB VCC UVLO High-Z VCC OVP Blinking Tj > 150oC B l i n ki n g The themal performance of the SC806 package requires a low impedance connection from the heat slug on the bottom of the package to an external ground plane. This is best accomplished by using a single large via under the device connected to a ground plane on the bottom exposed side of the pcb. The evaluation board uses 1 square inch of copper on the bottom of the pcb and is capable of 1A charging current. Overcurrent and Max Temperature Protection Overcurrent protection is inherent in all modes of operation. When the device is in charge-mode the output is current limited to either the pre-charge current limit value or the fast charge current limit value depending on the voltage at the output. Max die temperature protection is included on the SC806. This feature allows the SC806 to operate with maximum power dissipation by disabling the output current when the die temperature reaches OT. The result is that the SC806 will operate as a pulse charger in extreme power dissipation applications delivering the maximum allowable output current while regulating the internal die temperature to a safe level. 2004 Semtech Corp. The input and output bulk decoupling capacitors for the SC806 should be placed near the external terminals for the adpater and battery. This short low impedance loop is for the high current spikes that result from input/output hot-plugging of the charger. To minimize these current spikes should be minimized. A typical application requires a 0.1µF input/output capacitor. If the distance from the external terminals to the SC806 is greater than 1”, 0.1µ local decoupling capacitors at the SC806 may be required. 7 www.semtech.com SC806 POWER MANAGEMENT Evaluation Board Schematic CHRG+ 1 R806 R805 0 No Pop R4 No Pop CHRGB CPB 1 D1 D2 LED C1 1uF 3 10 2 8 7 1 D3 No Pop LED R1 3.01k DIS 1 R12 VOUT+ SC806 VCC VOUT CHRGB NTC CPB ITERM NOBAT IPRGM DIS GND 1 9 5 4 6 1 R7 No Pop C2 2.2uF No Pop R2 No Pop Charging Indicator R3 3.01K R8 No Pop ITRM IPGM NOBAT Adapter Present Indicator 1 1 1 1 R6 3.01k NTCV R9 3.01k R5 1e6 R10 3.01k CHRG- R11 3.01k VOUT1 1 Timing Diagram Charge Mode Timing UVLO OVP VCC Pre-Charge Threshold VOUT Fast Charge Soft Start IOUT Termination Current Re-Charge Threshold Pre-Charge CC-mode CV-mode Blink Low, High-Z CPB CHRGB High-Z DIS Low High-Z Low IC Enabled NTC = VCC NoBaT 2004 Semtech Corp. 8 www.semtech.com SC806 POWER MANAGEMENT Typical Characteristics SC806 Charge Curve 0.6 4.2 Vout (V) 0.4 3.8 0.3 3.6 0.2 3.4 V batt C hrgB * 3.2 0.1 Iout 3 0 0 0.5 1 1.5 Tim e (Hrs) 2 Fast Charge Output Current -vs- Resistance 2.5 3 Pre-Charge Output Current -vs- Resistance 900 90 800 80 700 70 Pre-Charge Iout (mA) Fast Charge Iout (mA) Iout (Amps) 0.5 4 600 500 400 300 Iout_Fast-C harge 200 100 60 50 40 30 Iout_Pre-C harge 20 10 0 0 1870 2140 2500 3000 3750 5000 7500 15000 30000 1870 2140 2500 3000 3750 5000 7500 15000 Programm ing Resistor (ohm s) Programm ing Resistor (ohm s) Output Voltage Load Regulation Output Voltage Line Regulation 4.188 30000 4.187 4.1865 4.187 4.186 V out C V V out C V 4.1855 Vout (Volts) Vout (Volts) 4.186 4.185 4.184 4.185 4.1845 4.184 4.1835 4.183 4.183 4.182 4.1825 4.181 4.182 0.075 0.1 0.2 0.3 0.4 0.5 4.5 Iout (Am ps) 2004 Semtech Corp. 4.75 5 5.25 5.5 5.75 6 Vcc (Volts) 9 www.semtech.com SC806 POWER MANAGEMENT Typical Characteristics Iprogram Voltage -vs- Iout Fast Charge I, Pre-Charge I Vcc < 4.2V -30.0% Fast C harge C urrentError -25.0% 1.8 0.00% 1.6 -1.00% -2.00% 1.4 Pre C harge C urrent Error Ipog Voltage (Volts) Percent Error in Output Currents -35.0% -20.0% -15.0% -10.0% -5.0% -3.00% 1.2 -4.00% 1 -5.00% 0.8 -6.00% 0.6 0.0% -7.00% Iprgm _V oltage 0.4 Iprgm V oltage Error -8.00% 0.2 5.0% -9.00% 0 3 4 4.5 5 5.5 -10.00% 15.00% 20.00% 40.00% 60.00% 80.00% 100.00% Output Current Percent, CC lim it = 100% Input Voltage VCC (volts) Fast Charge Output Current Line Regulation 800 Pre-Charge Output Current Line Regulation 900 51.9 795 51.8 800 790 600 775 500 770 765 400 51.6 Iout (mA) Iout (mA) 780 Iout (mA) Vcc=4.5 51.7 700 785 51.5 Iout_PretQ _vcc=5.0 51.4 Iout_PreQ _vcc=5.5 Iout_PreQ _vcc=4.5 51.3 Iout_fastQ _vcc=5.0 51.2 760 Iout_fastQ _vcc=5.5 300 Iout_fastQ _vcc=4.5 755 51.1 750 200 3.5 4 4.1 4.15 4.18 51 4.2 1 Vout Battery Voltage (Volts) 1.5 2 2.5 2.75 Vout Battery Voltage (Volts) Drop-out Voltage -vs- Iout 0.4 0.5 0.49 0.35 D rop-out_V oltage D rop-out R esistancer 0.47 0.25 0.46 0.2 0.45 0.44 0.15 0.43 0.1 Equivolent Drop-Out Resistance (ohms) Drop-out Voltage (Volts) 0.48 0.3 0.42 0.05 0.41 0 0.4 100 500 800 Output Current (m A) 2004 Semtech Corp. 10 www.semtech.com SC806 POWER MANAGEMENT SC806 State Diagram Under Voltage will force the SC806 into Shutdown Mode from any state. Shutdown Mode Vout/Iout off CHRGB High Z OVP> Vin > UVLO CPB=Low Yes Dis=Hi CC=Constant Current CV=Constant Voltage CHRGB Low Start Pre-Charge Yes Vout>2.8V Soft Start CC Mode Iout=150/Rterm Iout=1500/Rprog Vout=CV Yes Start CV Mode Iout<Iterm Yes CHRGB High Z Monitor Mode Vout=off OV or OT forces the output off and CHRGB blinks at 1Hz Charge resumes when the Fault is removed Vout< CV-100mV 2004 Semtech Corp. 11 www.semtech.com SC806 POWER MANAGEMENT Outline Drawing - MLPD-10, 3 x 3 Marking Instructions 806 yyww Top View Marking for the SC806 MLPD-10 Lead package: yyww = Date Code (Example: 0012) 2004 Semtech Corp. 12 www.semtech.com SC806 POWER MANAGEMENT Land Pattern - MLPD-10, 3 x 3 Contact Information Semtech Corporation Power Management Products Division 200 Flynn Road, Camarillo, CA 93012 Phone: (805)498-2111 FAX (805)498-3804 2004 Semtech Corp. 13 www.semtech.com