LTC1980 Combination Battery Charger and DC/DC Converter FEATURES DESCRIPTIO Single Controller IC Includes Battery Charger The LTC 1980 integrates PWM power control for charg- ing a battery and converting the battery voltage to a Plus DC/DC Converter regulated output or simultaneously charging the battery Wall Adapter Voltage May be Above or Below while powering a system load from an unregulated AC wall Battery Voltage adapter. Combining these features into a single IC pro- LDO Controller Allows Simultaneous Charging duces a smaller area and lower cost solution compared to and Regulating from Wall Adapter Input presently available multi-IC solutions. The LTC1980 shares Standalone Li-Ion Battery Charger Including Charge the discrete components for both the battery charger and Termination, Overvoltage Protection, Shorted-Cell the DC/DC converter thus minimizing size and cost relative Detection and Battery Recharge to dual controller solutions. Both the battery charger and Selectable 4.1V, 4.2V, 8.2V and 8.4V Float Voltages DC/DC converter use a current mode flyback topology for Simple NiMH and NiCd Battery Charger high efficiency and excellent transient response. Optional Pin Programmable Regulator Burst Mode Operation Burst Mode operation and power-down mode allow power and Shutdown for High Efficiency density, efficiency and output ripple to be tailored to the High Efficiency Current Mode 300kHz PWM application. Reduced Component Architecture Undervoltage Protection and Soft-Start Ensures The LTC1980 provides a complete Li-Ion battery charger Start-Up with Current Limited Wall Adapter with charge termination timer, preset Li-Ion battery volt- Small 24-Pin SSOP Package ages, overvoltage and undervoltage protection, and user- U programmable constant-current charging. Automatic bat- APPLICATIO S tery recharging, shorted-cell detection, and open-drain C/10 and wall plug detect outputs are also provided. User Digital Cameras programming allows NiMH and NiCd battery chemistries Handheld Computers to be charged as well. Personal Digital Assistants , LTC and LT are registered trademarks of Linear Technology Corporation. 1W to 10W Uninterruptable Power Supplies Burst Mode is a registered trademark of Linear Technology Corporation. Patents Pending. TYPICAL APPLICATIO Li-Ion Charger and DC/DC Converter Using One IC 3.3V Regulator Efficiency vs Load Current POWER FLOW 90 CHARGING BATTERY UNREGULATED OPERATION 85 WALL ADAPTER Li-Ion INPUT (3V TO 10V) BATTERY SYSTEM 80 POWER BAT-FET REG-FET 75 LDO/ SWITCH 70 3.3V 65 V = 3.6V BAT SYSTEM LOAD T = 25C A DC/DC 1.8V FIGURE 5 CONVERTERS 60 1.5V 10 100 1000 LTC1980 LOAD CURRENT (mA) 1980 TA01 1980 G04 1980f 1 EFFICIENCY (%) U ULTC1980 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) V to GND ............................................. 0.5V to 12V ORDER PART REG TOP VIEW NUMBER V to GND ............................................. 0.5V to 12V BAT PROG 1 24 SS PROG, I .............................................. 0.5V to 5V SENSE PROGT 2 23 OVP LTC1980EGN PROGT, REGFB, V , BATT1, BATT2 C REGFB 3 22 CAOUT TIMER, SS ............................................ 0.5V to V BIAS2 V 4 21 I C SENSE LDOFB, LDODRV .................................... 0.5V to V LDOFB 5 20 GND REG WA, V , REG....................................... 0.5V to 12V LDODRV 6 19 V BIAS2 BIAS1 MODE ................................................... 0.5V to V V 7 18 V REG BAT BIAS1 WA 8 17 TIMER V ......................................................... 0.5V to 5V BIAS2 BATT1 9 16 MODE OVP ............................................................ 0.5V to 5V BATT2 10 15 REG PGND to GND .................................... Connect Together RGTDR 11 14 BGTDR Operating Ambient Temperature Range PGND 12 13 V BIAS1 (Note 2) ................................................. 40C to 85C GN PACKAGE Storage Temperature Range ................. 65C to 125C 24-LEAD NARROW PLASTIC SSOP Lead Temperature (Soldering, 10 sec)................ 300C T = 125C, = 85C/W JMAX JA Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T = 25C. V = 2.4V, V = 5V, V unloaded. A BAT REG BAT SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V Positive Supply Voltage, V 2.85 10 V BAT BAT V Positive Supply Voltage, V 2.85 10 V REG REG V Feedback Voltage REGFB Tied to V 1.194 1.225 1.256 V FB C V Voltage on PROGT Pin PROGT Tied to V 1.194 1.225 1.256 V PROGT C I Burst Mode Operation Regulator Mode, REGFB = 1.5V 0.75 mA BURST Supply Current, Quiescent, V REG I Supply Current, Quiescent, V Regulator Mode, REGFB = 0V 2 4.3 mA HIGH REG I Supply Current in Shutdown Mode, V Mode = 0V 15 A SHDN REG V Positive-Going Undervoltage Lockout Voltage From Either V or V 2.45 2.7 2.85 V UVL BAT REG V Undervoltage Lockout Hysteresis From Either V or V 100 mV UVHYS BAT REG I Soft-Start Ramp Current BATT1 = 0, BATT2 = 0, Charger Mode 10 A SS V Output Float Voltage in Constant Voltage Mode BATT1 = 0, BATT2 = 0 4.059 4.1 4.141 V FLOAT0 V Output Float Voltage in Constant Voltage Mode BATT1 = 1, BATT2 = 0 4.158 4.2 4.242 V FLOAT1 V Output Float Voltage in Constant Voltage Mode BATT1 = 0, BATT2 = 1 (Note 3) 8.118 8.2 8.282 V FLOAT2 V Output Float Voltage in Constant Voltage Mode BATT1 = 1, BATT2 = 1 (Note 3) 8.316 8.4 8.484 V FLOAT3 V Output Float Voltage in Constant Voltage Mode BATT1 = Open, BATT2 = Dont Care 1.207 1.225 1.243 V FLOAT4 Measured from OVP Input V Recharge Threshold, Delta Voltage with Respect BATT2 = 0, BATT1 = 0 or 1 200 mV RCHG0 to Float Voltage V Recharge Threshold, Delta Voltage with Respect BATT2 = 1, BATT1 = 0 or 1 400 mV RCHG1 to Float Voltage 1980f 2 U WWW