LT1571 Series Constant-Current/ Constant-Voltage Battery Chargers with Preset Voltage and Termination Flag FEATURES DESCRIPTIO n Fast Charging of Li-Ion, NiMH and NiCd Batteries The LT 1571 PWM battery charger is a simple, efficient n Simple Charge Current Programming Requires solution to fast-charge rechargeable batteries including Only One Low Cost, 1/32W Resistor lithium-ion (Li-Ion), nickel-metal-hydride (NiMH) and n High Efficiency Charger with Up to nickel-cadmium (NiCd) using constant-current and/or 1.5A Charge Current constant-voltage control. The internal switch is capable n Precision 0.6% Internal Voltage Reference of delivering 1.5A DC current (2A peak current). The n Preset Battery Voltages: 4.1V, 4.2V, 8.2V, 8.4V onboard current sense resistor (0.1W ) allows simple n 500kHz or 200kHz Switching Frequency charge current programming to within 5% accuracy Minimizes Charger Size using a low cost external resistor. The constant-voltage n Low Reverse Battery Drain Current: 5m A output can be selected for 4.1V or 4.2V per cell with 0.6% n Flag Indicates Li-Ion Charge Completion accuracy. n 5% Typical Charge Current Accuracy LT1571 can charge batteries ranging from 1V to 20V. A n Low Shutdown Current saturating switch operating at 200kHz (LT1571-1, n LT1571-1: 200kHz, Adjustable Voltage LT1571-2) or 500kHz (LT1571-5) gives high efficiency LT1571-2: 200kHz, Fixed 8.2V or 8.4V and small charger size. A logic output (flag) indicates LT1571-5: 500kHz, Fixed 4.1V or 4.2V Li-Ion near full charge when the charge current drops to U 20% of the programmed value. The LT1571-1 and APPLICATIO S LT1571-2 are in a 28-pin fused lead narrow SSOP power n Cellular Phones, PDAs, Notebook Computers, package. The LT1571-5 is in a 16-pin fused lead narrow Portable Instruments SSOP power package. n Cradle Chargers for Li-Ion, NiCd, NiMH and , LTC and LT are registered trademarks of Linear Technology Corporation. Lead-Acid Rechargeable Batteries TYPICAL APPLICATION D3 D1 V MBRM120T3 IN MBRM120T3 8.2V TO 20V V SW CC (ADAPTER C * IN C1 OUTPUT) LT1571-5 10F 0.22m F L1** PROG BOOST 10m H 100k 1F D2 0.33F MMBD914L 6.19k 300 SENSE V C 1k CAP CHARGE FLAG 0.1F COMPLETE SELECT BAT 4.2V + C *** OUT BAT2 GND Li-Ion 22F BATTERY *TOKIN OR MARCON CERAMIC SURFACE MOUNT **COILTRONICS TP3-100, 10H, 2.2mm HEIGHT (0.8A CHARGING CURRENT) COILTRONICS TP1 SERIES, 10H, 1.8mm HEIGHT (<0.5A CHARGING CURRENT) *** PANASONIC EEFCD1B220 1571 F01 Figure 1. Compact Li-Ion Cellular Phone Charger (0.8A) 1 + U ULT1571 Series ABSOLUTE AXI U RATI GS (Note 1) Supply Voltage (V ) .............................................. 28V Operating Ambient CC BOOST Pin Voltage with Respect to V ................. 20V Temperature Range (Note 2) .................. 40 C to 85 C CC FLAG Pin Voltage ..................................................... V Operating Junction CC I (Average)........................................................ 1.5A Temperature Range .............................. 40 C to 125 C BAT Switch Current (Peak) .............................................. 2A Lead Temperature (Soldering, 10 sec).................. 300 C Storage Temperature Range ................. 65 C to 150 C UUW PACKAGE/ORDER I FOR ATIO TOP VIEW TOP VIEW **GND 1 28 GND** **GND 1 28 GND** **GND 2 27 GND** **GND 2 27 GND** TOP VIEW **GND 3 26 GND** **GND 3 26 GND** **GND 1 16 GND** SW 4 25 GND** SW 4 25 GND** SW 2 15 V * CC1 BOOST 5 24 V * BOOST 5 24 V * CC1 CC1 BOOST 3 14 V * CC2 BAT2 6 23 V * NC 6 23 V * CC2 CC2 BAT2 4 13 CAP FLAG 7 22 CAP FLAG 7 22 CAP 5 FLAG 12 PROG NC 8 21 PROG NC 8 21 PROG 6 11 SELECT V C SELECT 9 20 V V 9 20 V C C FB 7 10 SENSE BAT SENSE 10 19 BAT SENSE 10 19 BAT 8 9 **GND GND** **GND 11 18 GND** **GND 11 18 GND** **GND 12 17 GND** **GND 12 17 GND** GN PACKAGE 16-LEAD NARROW PLASTIC SSOP **GND 13 16 GND** **GND 13 16 GND** T = 125 C, q = 75 C/ W JMAX JA **GND 14 15 GND** **GND 14 15 GND** * V AND V SHOULD BE CONNECTED GN PACKAGE CC1 CC2 GN PACKAGE TOGETHER CLOSE TO THE PINS 28-LEAD NARROW PLASTIC SSOP 28-LEAD NARROW PLASTIC SSOP ** FOUR CORNER PINS ARE FUSED TO T = 125 C, q = 40 C/ W = 125 C, q = 40 C/ W T JMAX JA JMAX JA INTERNAL DIE ATTACH PADDLE FOR HEAT SINKING. CONNECT THESE FOUR * V AND V SHOULD BE CONNECTED TOGETHER * V AND V SHOULD BE CONNECTED TOGETHER CC1 CC2 CC1 CC2 PINS TO EXPANDED PC LANDS FOR CLOSE TO THE PINS CLOSE TO THE PINS PROPER HEAT SINKING ** ALL GND PINS ARE FUSED TO INTERNAL DIE ATTACH ** ALL GND PINS ARE FUSED TO INTERNAL DIE ATTACH PADDLE FOR HEAT SINKING. CONNECT THESE PINS TO PADDLE FOR HEAT SINKING. CONNECT THESE PINS TO EXPANDED PC LANDS FOR PROPER HEAT SINKING EXPANDED PC LANDS FOR PROPER HEAT SINKING 40 C/W THERMAL RESISTANCE ASSUMES AN INTERNAL 40 C/W THERMAL RESISTANCE ASSUMES AN INTERNAL GROUND PLANE DOUBLING AS A HEAT SPREADER GROUND PLANE DOUBLING AS A HEAT SPREADER ORDER PART NUMBER ORDER PART NUMBER ORDER PART NUMBER LT1571EGN-5 LT1571EGN-1 LT1571EGN-2 Consult factory for Industrial and Military grade parts. 2 U WWW