LTC3557EUF-1#PBF Linear Technology, LTC3557EUF-1#PBF Datasheet
LTC3557EUF-1#PBF
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LTC3557EUF-1#PBF Summary of contents
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... The LTC3557/LTC3557-1 is available in a low profi le 4mm × 4mm × 0.75mm 28-pin QFN package LTC, LTM and Burst Mode are registered trademarks of Linear Technology Corporation. Bat-Track and PowerPath are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. ...
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... LEAD FREE FINISH TAPE AND REEL LTC3557EUF#PBF LTC3557EUF#TRPBF LTC3557EUF-1#PBF LTC3557EUF-1#TRPBF Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based fi nish parts. For more information on lead free part marking, go to: For more information on tape and reel specifi ...
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POWER MANAGER ELECTRICAL CHARACTERISTICS The denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at T ● 5V 3.8V, ILIM0 = ILIM1 = 5V, WALL = EN1 = EN2 ...
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LTC3557/LTC3557-1 POWER MANAGER ELECTRICAL CHARACTERISTICS The denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at T ● 5V 3.8V, ILIM0 = ILIM1 = 5V, WALL = EN1 = ...
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SWITCHING REGULATOR ELECTRICAL CHARACTERISTICS The denotes the specifi cations which apply over the full operating temperature range, otherwise specifi cations are at T ● 3.8V, MODE = EN1 = EN2 = EN3 = 0V. ...
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LTC3557/LTC3557-1 TYPICAL PERFORMANCE CHARACTERISTICS Input Supply Current vs Temperature 0 BUS 1x MODE 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 –50 – 100 TEMPERATURE (°C) 35571 G01 Input Current Limit vs Temperature ...
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TYPICAL PERFORMANCE CHARACTERISTICS BAT BAT 600 500 400 300 200 BUS 10x MODE 100 PROG CLPROG 0 2.0 2.8 3.2 3.6 4.0 2.4 V (V) BAT 35571 G10 ...
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LTC3557/LTC3557-1 TYPICAL PERFORMANCE CHARACTERISTICS Oscillator Frequency vs Temperature 2.5 2 3.8V 2 2.2 IN 2.1 2.0 1 2. 2.7V IN 1.7 1.6 1.5 – ...
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TYPICAL PERFORMANCE CHARACTERISTICS 600mA Step-Down Switching Regulator Feedback Voltage vs Output Current 0.85 0.84 0.83 0.82 Burst Mode OPERATION 0.81 0.80 PULSE SKIP 0.79 0.78 0.77 3.8V 0.76 5V 0.75 0 100 1000 OUTPUT CURRENT (mA) 35571 G22 ...
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LTC3557/LTC3557-1 PIN FUNCTIONS V (Pin 16): Power Input for Step-Down Switching Regu- IN2 lators 2 and 3. This pin will generally be connected to V SW3 (Pin 17): Power Transmission (Switch) Pin for Step-Down Switching Regulator 3. V (Pin 18): ...
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BLOCK DIAGRAM V BUS 24 CLPROG 27 V NTC 18 BATTERY NTC 19 MONITOR CHRG 28 CHARGE STATUS ILIM0 1 ILIM1 2 EN1 9 EN2 10 EN3 11 MODE 8 RST2 ACPR WALL WALL DETECT IDEAL CC/CV ...
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LTC3557/LTC3557-1 OPERATION Introduction The LTC3557/LTC3557 highly integrated power management IC that includes a PowerPath controller, battery charger, an ideal diode, an always-on LDO, three synchronous step-down switching regulators as well as a buck regulator V controller. Designed specifi ...
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OPERATION The LTC3557/LTC3557-1 includes three 2.25MHz constant frequency current mode step-down switching regulators providing 400mA, 400mA and 600mA each. All step- down switching regulators can be programmed for a minimum output voltage of 0.8V and can be used to power ...
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LTC3557/LTC3557-1 OPERATION by the battery via the ideal diodes. The ideal diodes are fast enough to keep V from dropping with just the OUT recommended output capacitor. The ideal diode consists of a precision amplifi er that enables an on-chip ...
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OPERATION Battery Charger The LTC3557/LTC3557-1 includes a constant current/con- stant voltage battery charger with automatic recharge, automatic termination by safety timer, low voltage trickle charging, bad cell detection and thermistor sensor input for out of temperature charge pausing. When a ...
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LTC3557/LTC3557-1 OPERATION or high ambient thermal conditions and allows the user to push the limits of the power handling capability with a given circuit board design without risk of damaging the LTC3557/LTC3557-1 or external components. The benefi the ...
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OPERATION NTC Thermistor The battery temperature is measured by placing a negative temperature coeffi cient (NTC) thermistor close to the bat- tery pack. The NTC circuitry is shown in Figure 8. To use this feature connect the NTC thermistor, R ...
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LTC3557/LTC3557-1 OPERATION Step-Down Switching Regulator RST2 Operation The RST2 pin is an open-drain output used to indicate that step-down switching regulator 2 has been enabled and has reached its fi nal voltage. A 230ms delay is included from the time ...
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OPERATION Step-down Switching Regulator Dropout Operation It is possible for a step-down switching regulator’s input voltage to approach its programmed output voltage (e.g., a battery voltage of 3.4V with a programmed output voltage of 3.3V). When this happens, the PMOS ...
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LTC3557/LTC3557-1 OPERATION The inductor value also has an effect on Burst Mode operation. Lower inductor values will cause Burst Mode switching frequency to increase. Table 3 shows several inductors that work well with the step-down switching regulators. These inductors offer ...
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APPLICATIONS INFORMATION External HV Buck Control Through the V The WALL, ACPR and V pins can be used in conjunction C with an external high voltage buck regulator such as the ® LT 3480, LT3481 or LT3505 to provide power ...
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LTC3557/LTC3557-1 APPLICATIONS INFORMATION 36V 1μF LT3505 HIGH VOLTAGE BUCK CIRCUITRY Figure 5. LT3505 Buck Control Using V 5.0 4.5 4.0 3.5 3.0 2.5 2.5 3 3.5 BAT (V) Figure 6. LTC3557 V Voltage vs Battery Voltage ...
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APPLICATIONS INFORMATION Alternate NTC Thermistors and Biasing The LTC3557/LTC3557-1 provides temperature qualifi ed charging if a grounded thermistor and a bias resistor are connected to NTC. By using a bias resistor whose value is equal to the room temperature resistance ...
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LTC3557/LTC3557-1 APPLICATIONS INFORMATION From the Vishay Curve 1 R-T characteristics, r 0.2488 at 60°C. Using the above equation set to 46.4k. With this value of R point is about 16°C. Notice that the span is now 44°C rather ...
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APPLICATIONS INFORMATION no additional capacitance on the PROG pin, the battery charger is stable with program resistor values as high as 25k. However, additional capacitance on this node reduces the maximum allowed program resistor. The pole frequency at the PROG ...
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LTC3557/LTC3557-1 APPLICATIONS INFORMATION If an external buck switching regulator controlled by the LTC3557/LTC3557-1 V pin is used instead wall C adapter we see a signifi cant reduction in power dissipated by the LTC3557/LTC3557-1. This is because the ...
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... ADAPTER 100k NTC Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. OPTIONAL HIGH VOLTAGE 4 ...
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... PIN 1 NOTCH R = 0.20 TYP BOTTOM VIEW—EXPOSED PAD OR 0. 0.115 CHAMFER TYP 27 28 0.40 0. (UF28) QFN 0106 REVA 0.20 0.05 0.40 BSC ), 200mΩ Ideal Diode with 50mΩ MAX 35571fc LT 0808 REV C • PRINTED IN USA © LINEAR TECHNOLOGY CORPORATION 2007 ...