LTC4070 LINER [Linear Technology], LTC4070 Datasheet
LTC4070
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LTC4070 Summary of contents
Page 1
... The unique architecture of the LTC4070 allows for an extremely simple battery charger solution; requiring just one external resistor. The LTC4070 offers a pin selectable float voltage with 1% accuracy across the full range of operating temperature and shunt current. The integrated thermal battery quali- ...
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... LTC4070EDDB#PBF LTC4070EDDB#TRPBF LTC4070IDDB#PBF LTC4070IDDB#TRPBF LTC4070EMS8E#PBF LTC4070EMS8E#TRPBF LTC4070IMS8E#PBF LTC4070IMS8E#TRPBF Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: ...
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... The LTC4070I is guaranteed over the full –40°C to 125°C operating junction temperature range. Note that the maximum ambient temperature is determined by specific operating conditions in conjunction with board layout, the rated package thermal resistance and other environmental factors ...
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... LTC4070 TYPICAL PERFORMANCE CHARACTERISTICS Battery Discharge 1000 ADJ = GND 900 800 700 600 500 400 FALLING 300 200 RISING 100 (V) CC 4070 G01 I vs Temperature (ADJ = V ) CCQ CC 1000 900 800 700 600 500 400 300 200 100 0 – ...
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... G10 Hot Plug Transient 330μ 81Ω IN CH4 = I (10mA/DIV) CH1 = V IN (2V/DIV) CH2 = V CC (2V/DIV) CH3 = V (2V/DIV) 4ms/DIV LTC4070 T = 25°C, unless otherwise noted. A LBO/HBO vs I SINK = 3. (mA) SINK 4070 G11 Step Response with 800mAHr Battery 81Ω ...
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... LTC4070 PIN FUNCTIONS NTCBIAS (Pin 1): NTC Bias Pin. Connect a resistor from NTCBIAS to NTC, and a thermistor from NTC to GND. Float NTCBIAS when not in use. Minimize parasitic capacitance on this pin. NTC (Pin 2): Input to the Negative Temperature Coefficient Thermistor Monitoring Circuit. The NTC pin connects to ...
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... As the battery voltage approaches the float voltage, the LTC4070 shunts current away from the battery thereby reducing the charge current. The LTC4070 can shunt up to 50mA with float voltage accuracy of ±1% over temperature. The shunt current limits the maximum charge current, but the 50mA internal capability can be increased by adding an external P-channel MOSFET ...
Page 8
... HBHY tery is not at full charge. The input supply current of the LTC4070 drops to less than 450nA (typ) as the LTC4070 no longer shunts current to protect the battery. The NTCBIAS sample clock slows to conserve power, and the DRV pin is pulled For example, if the NTC thermistor requires the float voltage to be dropped by 100mV (ADJ = V programming ...
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... General Charging Considerations The LTC4070 uses a different charging methodology from previous chargers. Most Li-Ion chargers terminate the charging after a period of time. The LTC4070 does not have a discrete charge termination. Extensive measurements on Li-Ion cells show that the cell charge current drops to nanoamps with the shunt charge control circuit effectively terminating the charge ...
Page 10
... Vishay curve 2 thermistor). The LTC4070 uses a ratio of resistor values to measure battery temperature. The LTC4070 contains an internal fixed resistor voltage divider from NTCBIAS to GND with four tap points; NTC points are periodically compared against the voltage at the NTC pin to measure battery temperature ...
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... NOM thermistor) then the temperature trip points are 41.0°C, 49.8°C, 58.5°C, and 67.3°C. When using the NTC features of the LTC4070 it is important to keep in mind that the maximum shunt current increases as the float voltage, V drops with NTC conditioning. ...
Page 12
... WHEN CONNECTING TEST EQUIPMENT TO THE CIRCUIT TO AVOID ELECTRIC SHOCK. Figure 5. 4.2V AC Line Charging, UL Leakage Okay The LTC4070 can be used to charge a battery to a 4.2V float voltage from an AC line with a bridge rectifier as shown in the simple schematic in Figure 5. In this example, the four input 249k resistors are sized for acceptable UL leakage in the event that one of the resistors short ...
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... TYPICAL APPLICATIONS The LTC4070 status pins have sufficient drive strength to use with an LED, for a visual indication of charging status. Consider the application in Figure 7, where red LED D1 is connected to the LBO pin and turns off when the battery voltage is below V . Note that LED D1 discharges the ...
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... LTC4070 PACKAGE DESCRIPTION 0.61 ±0.05 (2 SIDES) 0.70 ±0.05 2.55 ±0.05 1.15 ±0.05 PACKAGE OUTLINE 0.25 ± 0.05 0.50 BSC 2.20 ±0.05 (2 SIDES) RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS NOTE: 1. DRAWING CONFORMS TO VERSION (WECD-1) IN JEDEC PACKAGE OUTLINE M0-229 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH ...
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... MAX SEATING PLANE 0.22 – 0.38 (.009 – .015) 0.65 TYP (.0256) BSC LTC4070 2.06 0.102 (.081 .004) 0.29 REF 1.83 0.102 (.072 .004) 0.05 REF DETAIL “B” CORNER TAIL IS PART OF DETAIL “B” THE LEADFRAME FEATURE. FOR REFERENCE ONLY NO MEASUREMENT PURPOSE ...
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... Standalone 250mA Li-Ion Battery Charger in 2mm × 2mm DFN ThinSOT is a trademark of Linear Technology Corporation. 16 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 ● 12V R IN 41.2Ω LTC4070 CC LBO FLOAT ADJ DRV Q1: FDN352AP NTCBIAS HBO D1 LTST NTC C190KGKT GND R LED 2 ...