ltc4001 Linear Technology Corporation, ltc4001 Datasheet
ltc4001
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ltc4001 Summary of contents
Page 1
... Additional features include shorted cell detection, tempera- ture qualified charging and overvoltage protection. The LTC4001 is available in a low profile (0.75mm) 16-lead (4mm × 4mm) QFN package. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. ...
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... DS(ON PACKAGE/ORDER I FOR ATIO ORDER PART NUMBER LTC4001EUF Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: Consult LTC Marketing for parts specified with wider operating temperature ranges. = 549Ω, unless otherwise specified. ...
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... Note 2: Operation with current limited wall adapters is allowed down to the undervoltage lockout threshold. Note 3: The LTC4001E is guaranteed to meet performance specifications from 0°C to 85°C. Specifications over the – 40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls. = 549Ω ...
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... LTC4001 W U TYPICAL PERFOR A CE CHARACTERISTICS Oscillator Frequency 1. 3.2V BAT 0.75 0.50 0.25 0 –0.25 –0.50 –0.75 –1. 5.5 4.5 V (V) IN 4001 G01 Dissipation of Figure 8 Circuit 1 BAT BAT 1.2 1 1.5A 0.8 BAT 0 BAT 0 500mA BAT 0.2 0 4.25 4.5 4.75 5 5.25 V (V) IN 4001 G04 Trickle Charge Current vs V ...
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... MOSFET switches. Connect to external inductor. EN (Pin 6): Enable Input Pin. Pulling the EN pin high places the LTC4001 into a low power state where the BAT drain current drops to less than 3µA and the supply current is reduced to less than 50µA. For normal operation, pull the pin low ...
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... LTC4001 CTIO S FAULT (Pin 10): Battery Fault. This pin is a logic high if a shorted battery is detected temperature fault is detected. A temperature fault occurs with the temperature monitor circuit enabled and the thermistor temperature is either below 0°C or above 50°C (typical). NTC (Pin 11): Input to the NTC (Negative Temperature Coefficient) Thermistor Temperature Monitoring Circuit ...
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... W BLOCK DIAGRA LTC4001 4001f 7 ...
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... LTC4001 U OPERATIO The LTC4001 is a constant current, constant voltage Li-Ion battery charger based on a synchronous buck architecture. Low power dissipation makes continuous high rate (2A) battery charging practical. The battery DC charge current is programmed by a resistor R DAC output current) at the PROG pin. The final battery float voltage is internally set to 4 ...
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... U OPERATIO Overvoltage, Chip Overtemperature and Short-Circuit Current Protection The LTC4001 includes overvoltage, chip overtemperature and several varieties of short-circuit protection. A comparator turns off both chargers (high rate and trickle) if battery voltage exceeds the float voltage by approximately 5%. This may occur in situations where the battery is accidentally disconnected while battery charg- ing is underway ...
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... U U APPLICATIO S I FOR ATIO Soft-Start and Compensation Capacitor Selection The LTC4001 has a low current trickle charger and a PWM-based high current charger. Soft-start is used when- ever the high rate charger is initially turned on, preventing high start-up current. Soft-start ramp rate is set by the internal 12.8µ ...
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... CHRG pin to an interrupt line. Serrations within this pulse are typically 500ns wide µPROCESSOR OUT IN 4001 F02 Figure 3. CHRG Temperature Fault Waveform LTC4001 = Time(Hrs) 0.0733µF). TIMER 4001 F03 20µs 667ms 4001f 11 ...
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... As the temperature drops, the resistance of the NTC thermistor rises. The LTC4001 is designed to go into hold mode when the value of the NTC thermistor increases to 2.82 times the value of R ...
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... The final solution is as shown if Figure 4 where R 121k 13.3k and R = 100k at 25°C. NTC Input and Output Capacitors The LTC4001 uses a synchronous buck regulator to pro- vide high battery charging current. A 10µF chip ceramic INSENSE 9 LTC4001 NTC BLOCK 0.74 • V ...
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... When the wall adapter reaches current limit, the wall adapter output voltage collapses and the LTC4001 PWM charger duty cycle ramps up to 100% (the topside PMOS switch in the LTC4001 buck regulator P -P stays on continuously) ...
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... Battery charging current continues to drop as the V rises, dropping to zero at V Because the voltage drop FLOAT. in the LTC4001 is very low when charge current is highest, power dissipation is also very low. Thermal Calculations (PWM and Trickle Charging) The LTC4001 operates as a linear charger when condition- ing (trickle) charging a battery and operates as a high rate buck battery charger at all other times ...
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... Using the LTC4001 in Applications Without a Battery The LTC4001 is normally used in end products that only operate with the battery attached (Figure 6). Under these conditions the battery is available to supply load transient currents. For indefinite operation with a powered wall adapter there are only two requirements— ...
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... APPLICATIO S I FOR ATIO 500 250 PWM CHARGE TRICKLE CHARGE TIME (ms TIME (ms TIME (ms) Figure 7. Battery-Less Start-Up LTC4001 4001 F07 4001f 17 ...
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... Recommended Components Manufacturers For a list of recommend component manufacturers, con- tact the Linear Technology application department. L1 1.5µH SW SENSE V BATSENS INSENSE 10µF R2 PGND 1k D1 LED LTC4001 CHRG NTC TO µP FAULT FROM µP EN PROG IDET TIMER SS GNDSENS C2 0.22µ 549Ω 549Ω ...
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... UF Package 16-Lead Plastic QFN (4mm × 4mm) (Reference LTC DWG # 05-08-1692) 0.72 ±0.05 PACKAGE OUTLINE 0.30 ±0.05 0.65 BSC 0.75 ± 0.05 2.15 ± 0.10 (4-SIDES) 0.200 REF 0.00 – 0.05 LTC4001 BOTTOM VIEW—EXPOSED PAD PIN 1 NOTCH R = 0.20 TYP OR 0.35 × 45° CHAMFER R = 0.115 TYP 15 16 0.55 ± 0. (UF16) QFN 10-04 0.30 ± 0.05 ...
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... LTC4001 RELATED PARTS PART NUMBER DESCRIPTION ® LT 1511 3A Constant Current/Constant Voltage Battery Charger High Efficiency, Minimum External Components to Fast Charge Lithium, LT1513 SEPIC Constant or Programmable Current/Constant Voltage Battery Charger LT1571 1.5A Switching Charger LTC1729 Li-Ion Battery Charger Termination Controller LT1769 2A Switching Charger ...