LTC3552-1 Linear Technology, LTC3552-1 Datasheet
LTC3552-1
Related parts for LTC3552-1
LTC3552-1 Summary of contents
Page 1
... When the input supply (wall adapter or USB supply) is removed, the LTC3552-1 enters a low current state dropping the battery drain current to less than 2µA. Thermal regulation maximizes charge rate without risk of overheating ...
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... LTC3552 ABSOLUTE AXI U RATI GS (Note 1) Input Supply Voltage (V ) ......................... –0.3V to 10V IN PROG, ITERM .................................. –0. BAT .............................................................. –0. ⎯ C ⎯ H ⎯ R ⎯ ⎯ P ⎯ W ⎯ ⎯ E ⎯ N ......................................... –0.3V to 10V BAT Short-Circuit Duration ............................Continuous BAT Pin Current ..........................................................1A PROG Pin Current ....................................................1mA V Supply Voltage ...................................... – ...
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... Note 7: The regulator power switch on-resistances are guaranteed by correlation to wafer level measurements. Note calculated from the ambient temperature T J dissipation P according to the following formula: D • θ LTC3552-1 MIN TYP MAX UNITS 0.93 1 1.07 V 0.35 0.6 V 0.35 0 100 140 ...
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... LTC3552-1 W TYPICAL PERFOR A CE CHARACTERISTICS Battery Charger PROG Pin Voltage vs Supply Voltage (Constant-Current Mode) 1.015 BAT R = 10k PROG 1.010 1.005 1.000 0.995 0.990 0.985 4 4.5 5 5 (V) IN Regulated Output (Float) Voltage vs Charge Current 4. 1.25k 4.24 PROG 4.22 4.20 4.18 4.16 4.14 4.12 4.10 100 200 ...
Page 5
... R = 10k PROG 6 6 (V) IN 35521 G10 4.16 4.14 4.12 4.10 4.08 4.06 4. 100 125 35521 G12 LTC3552 25°C Unless Otherwise Specifi ed. A Charge Current vs Ambient Temperature ONSET OF THERMAL REGULATION PROG 400 300 BAT θ = 40°C 10k PROG 100 0 ...
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... LTC3552-1 W TYPICAL PERFOR A CE CHARACTERISTICS Switching Regulator Burst Mode Operation SW 5V/DIV I L 200mA/DIV V OUT1 RIPPLE 20mV/DIV V = 3.6V 2µs/DIV 1.8V OUT1 I = 60mA LOAD REGULATOR 1; CIRCUIT OF FIGURE 2 Effi ciency vs Supply Voltage 100 I = 1mA OUT I = 10mA OUT 100mA OUT I = 800mA ...
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... OUT2 –1.0 = 3.6V –1.5 Burst Mode OPERATION CIRCUIT OF FIGURE 2 –2 100 1000 LOAD CURRENT (mA) 35521 G23 100 V = 3.6V CC 100 1000 35521 G26 LTC3552 25°C Unless Otherwise Specifi ed. A Line Regulation 0 200mA OUT 0.4 0.3 0 1.8V OUT1 0.1 0 –0.1 –0.2 –0 3.6V CC – ...
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... LTC3552 CTIO S ITERM (Pin 1): Charge Termination Program. The charge termination current threshold is programmed by connect- ing a 1% resistor ground. The current threshold TERM ITERM, is set by the following formula: 100 TERM TERM R TERM BAT (Pin 2): Charge Current Output. Provides charge cur- rent to the battery from the internal P-channel MOSFET, and regulates the fi ...
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... PWR – SLOPE COMP EN – SLEEP I TH BURST EA + 0.35V LATCH R Q SWITCHING UV LOGIC AND BLANKING CIRCUIT OV OSC LTC3552 1000× – + BAT 2 5µ – REF 1.21V 0.1V R5 ITERM 1 PROG 13 GND 17 BURST V CLAMP CC – ...
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... LTC3552-1 U OPERATIO The LTC3552-1 is made up of two circuit blocks: a stand- alone constant-current/constant-voltage linear charger for a single-cell lithium-ion battery and a high effi ciency dual DC/DC switching regulator. The charger can deliver up to 950mA of charge current (using a good thermal PCB lay- out) with a fi nal fl oat voltage accuracy of ±1%. An internal P-channel power MOSFET and thermal regulation circuitry are included ...
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... The output voltages are fi xed at 1.8V for regulator 1 and at 1.575V for regulator 2. The resistive divider feedback networks are integrated inside the LTC3552-1. An error amplifi er compares the divided output voltage (V adjusts the peak inductor current accordingly. ...
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... BAT pin. In this state, any load on the BAT pin must be supplied by the battery. * Any external sources that hold the ITERM pin above 100mV will prevent the LTC3552-1 , from TERM from terminating a charge cycle. ...
Page 13
... 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 LTC3552-1 requires to operate. Table 1 shows some typical surface mount inductors that work well in LTC3552-1 applications. ...
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... In most cases, 0.1µF to 1µF of X5R dielectric ceramic capacitors should also be placed close the LTC3552-1 in parallel with the main capacitors for high frequency decoupling. Ceramic Input and Output Capacitors Higher value, lower cost ceramic capacitors are now be OUT coming available in smaller case sizes ...
Page 15
... L1, L2, etc. are the individual losses as a percent- age of input power. Although all dissipative elements in the circuit produce losses, four main sources usually account for most of the losses in LTC3552-1 circuits switching losses The V Electrical Characteristics which excludes MOSFET dri- ver and control currents. V (< ...
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... 120°C – 54.4° 65.6°C A The LTC3552-1 can be used above 65°C ambient but the charge current will be reduced from the programmed 800mA. The approximate current at a given ambient temperature can be approximated by BAT Using the previous example with an ambient temperature of 70° ...
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... In order to deliver maximum charge current under all conditions critical that the exposed metal pad on the backside of the LTC3552-1 package is soldered to the PC board ground. Failure to make thermal contact between the exposed pad on the backside of the package and the copper board will result in thermal resistances far greater than 40° ...
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... DIODE OF FET Figure 4. Low Loss Input Reverse Polarity Protection Design Example As a design example, assume the LTC3552-1 is used in a single lithium-ion battery-powered cellular phone ap- plication. Starting with the charger, choosing R programs the charger for 806mA. A good rule of thumb for I is one tenth the full charge current TERMINATE is picked ...
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... OUT1 C C OUT2 FF2 10µF 330pF V V CER FB2 FB1 GND ITERM PROG DHC Package 16-Lead Plastic DFN (5mm × 3mm) (Reference LTC DWG # 05-08-1706) LTC3552-1 V OUT1 C OUT1 C OUT2 V OUT2 35521 F06 500mA 4.2V + 1-CELL 10µF Li-Ion BATTERY 2.2µH V OUT1 1.8V/800mA ...
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... McCarthy Blvd., Milpitas, CA 95035-7417 ● (408) 432-1900 FAX: (408) 434-0507 U Li-Ion Charger and Step-Down Converters with PowerPath V RUN1 IN RUN2 CHRG 1k PWR BAT EN LTC3552-1 4.7µH SW2 SW1 V V OUT2 OUT1 C C OUT2 FF2 10µF 330pF V V CER FB2 FB1 GND ...