LTC3550-1 Linear Technology, LTC3550-1 Datasheet
LTC3550-1
Related parts for LTC3550-1
LTC3550-1 Summary of contents
Page 1
... With power applied to both inputs, the LTC3550-1 can be put into shutdown mode reducing the DCIN supply current to 20μA, the USBIN supply current to 10μA, and the battery drain current to less than 2μ ...
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... LTC3550 ABSOLUTE AXI U RATI GS (Note 1) DCIN, USBIN .............................................. –0.3V to 10V ENABLE, ⎯ C ⎯ H ⎯ R ⎯ ⎯ P ⎯ W ⎯ USBPWR ............... –0.3V to 10V BAT, IDC, IUSB, ITERM ................................ –0. ............................................................... –0. RUN, V ..................................................–0. OUT SW (DC) ........................................–0. DCIN Pin Current (Note 2) ..........................................1A USBIN Pin Current (Note 2) ...
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... I = 10% to 90% Full-Scale BAT I = 100mA OUT 1.7V CC OUT (Note 1.7V OUT LOAD V = 1.94V OUT LOAD 5.5V RUN CC LTC3550-1 MIN TYP MAX UNITS 140 180 220 140 180 220 ● 250 800 µA ● 50 100 µ ...
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... LTC3550-1 ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi cations are at T SYMBOL PARAMETER f Oscillator Frequency OSC P-Channel FET PFET DS(ON N-Channel FET NFET DS(ON Leakage Current LSW Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime ...
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... DCIN USBIN (V) CHRG 3550-1 G07 LTC3550 25°C, unless otherwise noted. A IDC Pin Voltage vs Temperature (Constant-Current Mode) 1.008 1.006 1.004 1.002 V DCIN 1.000 V = 4.3V DCIN 0.998 0.996 0.994 0.992 75 100 –50 –25 ...
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... LTC3550-1 W TYPICAL PERFOR A CE CHARACTERISTICS Charge Current vs Ambient Temperature 1000 ONSET OF THERMAL REGULATION 800 R = 1.25k IDC 600 IDC IUSB 400 200 DCIN USBIN BAT θ = 40°C –50 – TEMPERATURE (°C) DCIN Power FET On-Resistance vs Temperature ...
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... V (V) CC 3550-1 G22 Oscillator Frequency vs Temperature 1. 3.6V CC 1.65 1.60 1.55 1.50 1.45 1.40 1.35 1.30 125 –50 – TEMPERATURE (°C) 3550-1 G25 LTC3550 25°C, unless otherwise noted. A Battery Drain Current vs Temperature 4.2V BAT (NOT CONNECTED) DCIN USBIN –1 –50 – 100 TEMPERATURE (°C) 3550-1 G20 Buck Regulator Effi ...
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... LTC3550-1 W TYPICAL PERFOR A CE CHARACTERISTICS Buck Regulator Output Voltage vs Load Current 1. 3.6V CC 1.89 1.88 1.87 1.86 1.85 0 100 200 300 400 500 600 700 I (mA) LOAD Buck Regulator Supply Current 1.875V OUT LOAD (V) CC Switch Leakage Current vs V ...
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... AC COUPLED I L 500mA/DIV 35501 G36 V = 3.6V 20µs/DIV 0mA TO 600mA LOAD V OUT 100mV/DIV AC COUPLED 500mA/DIV 35501 G39 20µs/DIV LTC3550 25°C, unless otherwise noted. A Load Step V OUT 100mV/DIV AC COUPLED I L 500mA/DIV 35501 G37 V = 3.6V 20µs/DIV 50mA TO 600mA ...
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... LED. ⎯ C ⎯ H ⎯ R ⎯ G (Pin 5): Open-Drain Charge Status Output. When the LTC3550-1 is charging, the ⎯ C ⎯ H ⎯ R ⎯ G pin is pulled low by an internal N-channel MOSFET. When the charge cycle is completed, ⎯ C ⎯ H ⎯ R ⎯ G becomes high impedance. This output is capable of sinking up to 10mA, making it suitable for driving an LED ...
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... DC_ENABLE USB_ENABLE THERMAL CHARGER CONTROL REGULATION 100mV BAT BAT BAT /1000 /1000 /1000 ITERM IDC IUSB ITERM IDC IUSB LTC3550-1 USBIN 1 FREQ OSC SHIFT SLOPE COMP + 3.95V – BURST CLAMP BAT 5Ω – COMP LATCH ...
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... REMOVED REMOVED OR DCIN POWER APPLIED ENABLE ENABLE DRIVEN HIGH DRIVEN LOW DCIN POWER USBIN POWER REMOVED REMOVED OR DCIN POWER APPLIED Figure 1. LTC3550-1 State Diagram of a Charge Cycle > DCIN USBIN ), the ITERM CHARGE MODE FULL CURRENT CHRG STATE: PULLDOWN I < I BAT ...
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... The charge status output ( ⎯ C ⎯ H ⎯ R ⎯ has two states: pull- down and high impedance. The pull-down state indicates that the LTC3550 charge cycle. Once the charge cycle has terminated or the LTC3550-1 is disabled, the pin state becomes high impedance. The pull-down state is strong enough to drive an LED and is capable of sink- ing up to 10mA ...
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... The USB power status output (USBPWR) has two states: pull-down and high impedance. The high impedance state indicates that the LTC3550-1 is being powered from the USBIN input. The pull-down state indicates that the charger is either powered from DCIN UVLO condition (see Table 1) ...
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... USB sup ply ) ) starting point for setting ripple current is ΔI (40% of 600mA). ∆ Any external sources that hold the ITERM pin above 100mV will prevent the LTC3550-1 from terminating a charge cycle. LTC3550-1 , from the ITERM pin to ground. ITERM 100 V = ...
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... The choice of which style inductor to use often depends more on the price vs size requirements and any radiated fi eld/EMI requirements than on what the LTC3550-1 requires to operate. Table 2 shows some typical surface mount inductors that work well in LTC3550-1 applications. ...
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... ESR make them ideal for switching regulator applications. Because the LTC3550-1’s control loop does not depend on the output capacitor’s ESR for stable operation, ceramic capacitors can be used freely to achieve very low output ripple and small circuit size ...
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... I BAT = RISE rent. Example: An LTC3550-1 operating from a 5V wall adapter (on the DCIN input) is programmed to supply 650mA full-scale current to a discharged Li-Ion battery with a is the thermal voltage of 2.7V. JA The charger power dissipation is calculated to be: P D(CHARGER) ...
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... V • IN BAT ) For optimum performance critical that the exposed metal pad on the backside of the LTC3550-1 package is properly soldered to the PC board ground. When correctly 2 soldered to a 2500mm double sided 1oz copper board, the LTC3550-1 has a thermal resistance of approximately 40°C/W. Failure to make thermal contact between the ex- ...
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... The thermal resistance of the package can be further enhanced by increasing the area of the copper used for PC board ground. Design Example As a design example, assume the LTC3550-1 is used in a single lithium-ion battery-powered cellular phone application. The battery is charged by either plugging a wall adapter into the phone or putting the phone in a USB cradle ...
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... GND GND 9 17 Figure 5. DC-DC Converter Layout Diagram VIA TO V OUT GND C OUT Figure 6. DC-DC Converter Suggested Layout LTC3550-1 will require an RMS cur temperature LOAD(MAX) will require an ESR of less than 0.25Ω. In most OUT BOLD LINES INDICATE HIGH CURRENT PATHS L1 – V OUT C ...
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... (mA) LOAD Figure 7b. Buck Regulator Effi ciency vs Output Current U Full Featured Dual Input Charger Plus Step-Down Converter LTC3550-1 BAT DCIN 1k USBIN PWR 1µF 1µF CHRG V CC IUSB SW IDC 2.1k 1.24k V ITERM 1% 1% OUT GND 1k 1% ...
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... Plastic DFN (5mm × 3mm) (Reference LTC DWG # 05-08-1706) 0.65 ±0.05 PACKAGE OUTLINE 0.25 ± 0.05 0.50 BSC 4.40 ±0.05 (2 SIDES) 5.00 ±0.10 (2 SIDES 0.20 TYP 3.00 ±0.10 1.65 ± 0.10 (2 SIDES) (2 SIDES) 0.75 ±0.05 0.00 – 0.05 LTC3550 0.115 0.40 ± 0.10 TYP 9 16 PIN 1 NOTCH (DHC16) DFN 1103 8 1 0.25 ± 0.05 0.50 BSC 4.40 ±0.10 (2 SIDES) BOTTOM VIEW—EXPOSED PAD 23 35501f ...
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... Charger LTC4077 Dual Input Standalone Li-Ion Battery Charger PowerPath and ThinSOT are trademarks of Linear Technology Corporation. Linear Technology Corporation 24 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 ● U LTC3550-1 DCIN 1µF USBIN V CC 4.7µF 1µF IUSB BAT 2.2µH SW IDC ...