LT1510/LT1510-5 Constant-Voltage/ Constant-Current Battery Charger FEATURES n plest, most efficient solution to fast-charge modern re- Charges NiCd, NiMH and Lithium-Ion Batteries 1 chargeable batteries including lithium-ion (Li-Ion), nickel- Only One / W Resistor Is Needed to Program 10 metal-hydride (NiMH)* and nickel-cadmium (NiCd)* that Charging Current n require constant-current and/or constant-voltage charg- High Efficiency Current Mode PWM with 1.5A ing. The internal switch is capable of delivering 1.5A DC Internal Switch and Sense Resistor n current (2A peak current). The 0.1 onboard current 3% Typical Charging Current Accuracy n sense resistor makes the charging current programming Precision 0.5% Voltage Reference for Voltage very simple. One resistor (or a programming current from Mode Charging or Overvoltage Protection n a DAC) is required to set the full charging current (1.5A) to Current Sensing Can Be at Either Terminal of within 5% accuracy. The LT1510 with 0.5% reference the Battery n voltage accuracy meets the critical constant-voltage charg- Low Reverse Battery Drain Current: 3A n ing requirement for lithium cells. Charging Current Soft Start n Shutdown Control The LT1510 can charge batteries ranging from 2V to 20V. n 500kHz Version Uses Small Inductor Ground sensing of current is not required and the batterys U negative terminal can be tied directly to ground. A saturat- APPLICATIONS ing switch running at 200kHz (500kHz for LT1510-5) gives high charging efficiency and small inductor size. A block- n Chargers for NiCd, NiMH and Lithium Batteries ing diode is not required between the chip and the battery n Step-Down Switching Regulator with Precision because the chip goes into sleep mode and drains only 3A Adjustable Current Limit when the wall adaptor is unplugged. Soft start and shutdown features are also provided. The LT1510 is available in a 16-pin DESCRIPTION fused lead power SO package with a thermal resistance of 50C/W, an 8-pin SO and a 16-pin PDIP. With switching frequency as high as 500kHz, The LT 1510 , LTC and LT are registered trademarks of Linear Technology Corporation. current mode PWM battery charger is the smallest, sim- * NiCd and NiMH batteries require charge termination circuitry (not shown in Figure 1). TYPICAL APPLICATIONS D3 C1 D1 1N5819 D3 11V TO 28V C1 0.22F 1N5819 D1 MBRM120T3 8.2V TO 20V SW V 0.22F MBRM120T3 CC + SW V CC C * IN + + 10F C * IN + 10F BOOST PROG 1F BOOST PROG L1** 300 1F 3.83k L1** 33H LT1510 300 D2 6.19k 10H LT1510-5 D2 1N914 GND V 0.1F C MMBD914L 1k GND V 0.1F C 1k OVP OVP SENSE BAT + SENSE BAT + C OUT 4.2V + 22F + C *** Q3 OUT 4.2V TANT + VN2222 22F Q3 4.2V 2N7002 R3 R3 240k NOTE: COMPLETE LITHIUM-ION CHARGER, NO TERMINATION REQUIRED 0.25% 70.6k TOKIN OR MARCON CERAMIC SURFACE MOUNT * 0.25% R4 NOTE: COMPLETE LITHIUM-ION CHARGER, NO TERMINATION REQUIRED ** COILTRONICS TP3-100, 10H, 2.2mm HEIGHT (0.8A CHARGING CURRENT) 100k R4 COILTRONICS TP1 SERIES, 10H, 1.8mm HEIGHT (<0.5A CHARGING CURRENT) * TOKIN OR MARCON CERAMIC SURFACE MOUNT 0.25% 100k *** PANASONIC EEFCD1B220 ** COILTRONICS CTX33-2 1510 F02 0.25% OPTIONAL, SEE APPLICATIONS INFORMATION 1510 F01 OPTIONAL, SEE APPLICATIONS INFORMATION Figure 1. 500kHz Smallest Li-Ion Cell Phone Charger (0.8A) Figure 2. Charging Lithium Batteries (Efficiency at 1.3A > 87%) 1 U ULT1510/LT1510-5 ABSOLUTE MAXIMUM RATINGS Operating Ambient Temperature Range Supply Voltage (V )............................................ 30V MAX Commercial ............................................. 0C to 70C Switch Voltage with Respect to GND ...................... 3V Extended Commercial (Note 7) ........... 40C to 85C Boost Pin Voltage with Respect to V ................... 30V CC Industrial (Note 8) .............................. 40C to 85C Boost Pin Voltage with Respect to GND ................. 5V Operating Junction Temperature Range V , PROG, OVP Pin Voltage ...................................... 8V C LT1510C (Note 7) ............................. 40C to 125C I (Average)........................................................ 1.5A BAT LT1510I ............................................ 40C to 125C Switch Current (Peak)............................................... 2A Lead Temperature (Soldering, 10 sec).................. 300C Storage Temperature Range ................. 65C to 150C PACKAGE/ORDER INFORMATION ORDER PART ORDER PART TOP VIEW TOP VIEW TOP VIEW NUMBER NUMBER SW 1 8 V CC **GND 1 16 GND** **GND 1 16 GND** BOOST 2 7 PROG 2 15 V 2 15 V SW CC2 SW CC2 LT1510CGN LT1510CN GND 3 6 V C 3 V 3 V BOOST 14 BOOST 14 CC1 CC1 LT1510IGN LT1510CS SENSE 4 5 BAT GND 4 13 PROG GND 4 13 PROG LT1510-5CGN LT1510IN 5 12 V 5 12 V OVP C OVP C LT1510-5IGN LT1510IS S8 PACKAGE 6 NC 6 BAT NC 11 SENSE 11 8-LEAD PLASTIC SO SENSE 7 10 BAT GND 7 10 GND T = 125C, = 125C/ W JMAX JA 8 9 GND** 8 9 GND** **GND **GND ORDER PART GN PACKAGE (0.015 IN) S PACKAGE* N PACKAGE 16-LEAD PLASTIC SSOP 16-LEAD PDIP 16-LEAD PLASTIC SO NUMBER GN PART T = 125C, = 75C/ W (N) T = 125C, = 75C/ W JMAX JA MARKING JMAX JA T = 125C, = 50C/ W (S)* LT1510CS8 JMAX JA ** FOUR CORNER PINS ARE FUSED TO 1510 LT1510IS8 INTERNAL DIE ATTACH PADDLE FOR *V AND V SHOULD BE CONNECTED CC1 CC2 HEAT SINKING. CONNECT THESE FOUR 1510I TOGETHER CLOSE TO THE PINS. PINS TO EXPANDED PC LANDS FOR ** FOUR CORNER PINS ARE FUSED TO S8 PART MARKING 15105 PROPER HEAT SINKING. INTERNAL DIE ATTACH PADDLE FOR 15105I HEAT SINKING. CONNECT THESE FOUR 1510 PINS TO EXPANDED PC LANDS FOR PROPER HEAT SINKING. 1510I Consult factory for Military grade parts. ELECTRICAL CHARACTERISTICS V = 16V, V = 8V, V (maximum operating V ) = 28V, no load on any outputs, unless otherwise noted. (Notes 7, 8) CC BAT MAX CC PARAMETER CONDITIONS MIN TYP MAX UNITS Overall Supply Current V = 2.7V, V 20V l 2.90 4.3 mA PROG CC V = 2.7V, 20V < V V l 2.91 4.5 mA PROG CC MAX DC Battery Current, I (Note 1) 8V V 25V, 0V V 20V, T < 0C l 0.91 1.09 A BAT CC BAT J R = 4.93k l 0.93 1.0 1.07 A PROG R = 3.28k (Note 4) l 1.35 1.5 1.65 A PROG R = 49.3k l 75 100 125 mA PROG T < 0C l 70 130 mA J V = 28V, V = 20V CC BAT R = 4.93k l 0.93 1.0 1.07 A PROG R = 49.3k l 75 100 125 mA PROG 2 U W U W U WW