Datasheet LTC4070 (Analog Devices)

LTC4070 Li-Ion/Polymer Shunt Battery Charger System
FEATURES DESCRIPTION
n
Low Operating Current (450nA)
The LTC®4070 allows simple charging of Li-Ion/Polymer n
1% Float Voltage Accuracy Over Full Temperature
batteries from very low current, intermittent or continu-
and Shunt Current Range
ous charging sources. The 450nA to 50mA operating cur- n
50mA Maximum Internal Shunt Current
rent makes charging possible from previously unusable
(500mA with External PFET)
sources. With the addition of an external pass device, n
Pin Selectable Float Voltage Options:
shunt current may be boosted to 500mA. Stacked cell high
4.0V, 4.1V, 4.2V
voltage battery packs are inherently balanced with shunt n
Ultralow Power Pulsed NTC Float Conditioning for
charging. With its low operating current, the LTC4070 is
Li-Ion/Polymer Protection
well suited to charge thin film batteries in energy harvest- n Suitable for Intermittent, Continuous and Very Low ing applications where charging sources may be intermit- Power Charging Sources tent or very low power. The unique architecture of the n Low and High Battery Status Outputs LTC4070 allows for an extremely simple battery charger n Simple Low Voltage Load Disconnect Application solution; requiring just one external resistor. n Thermally Enhanced, Low Profile (0.75mm) The LTC4070 offers a pin selectable float voltage with 1% 8-Lead (2mm × 3mm) DFN and MSOP Packages accuracy across the full range of operating temperature and shunt current. The integrated thermal battery quali-
APPLICATIONS
fier extends battery lifetime and improves reliability by n automatically reducing the battery float voltage at NTC Low Power Li-Ion/Polymer Battery Back-Up n thermistor temperatures above 40°C. The LTC4070 also Solar Power Systems with Back-Up n provides both low and high battery status outputs. For Memory Back-Up n applications requiring pack protection, see LTC4071. Embedded Automotive n Thin Film Batteries The device is offered in two thermally enhanced packages, n Energy Scavenging/Harvesting a compact low profile (0.75mm) 8-lead (2mm × 3mm) All registered trademarks and trademarks are the property of their respective owners. DFN and an 8-lead MSOP package.
TYPICAL APPLICATION NTC Overtemperature Battery Float Simple Shunt Charger with Load Disconnect Voltage Qualifying and NTC Conditioning
4.3 VIN ADJ = V 4.2 CC RIN Q1:FDR8508 ADJ = FLOAT 4.1 VCC LBO (V) ADJ = GND 4.0 ADJ NTCBIAS V F LTC4070 10k 3.9 NTC GND + 3.8 T Li-Ion 3.7 0 20 40 60 80 100 NTHS0805N02N1002F 4070 TA01a TEMPERATURE (°C) 4070 TA01b Rev. D Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts