Datasheet LT1510, LT1510-5 (Analog Devices)

LT1510/LT1510-5 Constant-Voltage/ Constant-Current Battery Charger
FEATURES
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Charges NiCd, NiMH and Lithium-Ion Batteries ––
plest, most efficient solution to fast-charge modern re-
Only One 1/
chargeable batteries including lithium-ion (Li-Ion), nickel-
10W Resistor Is Needed to Program Charging Current
metal-hydride (NiMH)* and nickel-cadmium (NiCd)* that ■
High Efficiency Current Mode PWM with 1.5A
require constant-current and/or constant-voltage charg-
Internal Switch and Sense Resistor
ing. The internal switch is capable of delivering 1.5A DC ■
3% Typical Charging Current Accuracy
current (2A peak current). The 0.1Ω onboard current ■
Precision 0.5% Voltage Reference for Voltage
sense resistor makes the charging current programming
Mode Charging or Overvoltage Protection
very simple. One resistor (or a programming current from ■ Current Sensing Can Be at Either Terminal of a DAC) is required to set the full charging current (1.5A) to the Battery within 5% accuracy. The LT1510 with 0.5% reference ■ Low Reverse Battery Drain Current: 3µA voltage accuracy meets the critical constant-voltage charg- ■ Charging Current Soft Start ing requirement for lithium cells. ■ Shutdown Control The LT1510 can charge batteries ranging from 2V to 20V. ■ 500kHz Version Uses Small Inductor Ground sensing of current is not required and the battery’s
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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- Chargers for NiCd, NiMH and Lithium Batteries ■ ing diode is not required between the chip and the battery Step-Down Switching Regulator with Precision because the chip goes into sleep mode and drains only 3µA Adjustable Current Limit when the wall adaptor is unplugged. Soft start and shutdown
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features are also provided. The LT1510 is available in a 16-pin
DESCRIPTION
fused lead power SO package with a thermal resistance of 50°C/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).
U TYPICAL APPLICATIONS
D3 C1 D3 D1 1N5819 C1 D1 0.22µF 1N5819 11V TO 28V MBRM120T3 0.22µF MBRM120T3 8.2V TO 20V SW VCC + SW VCC + CIN* + C – IN* + 10µF 10µF – BOOST PROG 1µF BOOST PROG L1** 1µF 300Ω 3.83k L1** 300Ω 33µH LT1510 6.19k D2 10µH LT1510-5 D2 1N914 GND V 0.1µF MMBD914L C GND V 1k C 0.1µF 1k OVP OVP SENSE BAT + SENSE BAT + + COUT 4.2V + 22µF COUT*** Q3† 4.2V TANT + 22µF Q3† VN2222 2N7002 4.2V R3 R3 240k NOTE: COMPLETE LITHIUM-ION CHARGER, NO TERMINATION REQUIRED 70.6k 0.25% TOKIN OR MARCON CERAMIC SURFACE MOUNT * 0.25% R4 COILTRONICS TP3-100, 10 ** µH, 2.2mm HEIGHT (0.8A CHARGING CURRENT) NOTE: COMPLETE LITHIUM-ION CHARGER, NO TERMINATION REQUIRED R4 100k COILTRONICS TP1 SERIES, 10µH, 1.8mm HEIGHT (<0.5A CHARGING CURRENT) 100k * TOKIN OR MARCON CERAMIC SURFACE MOUNT 0.25% PANASONIC EEFCD1B220 *** 0.25% ** COILTRONICS CTX33-2 1510 F02 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%)
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