LTC3553 Linear Technology Corporation, LTC3553 Datasheet
LTC3553
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LTC3553 Summary of contents
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... With all supplies enabled in standby mode, the quiescent cur- rent drawn from the battery is only 12μA. The LTC3553 is available in an ultrathin (0.55mm) 3mm × 3mm 20-pin UTQFN package. ...
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... ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL LTC3553EPD#PBF LTC3553EPD#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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... Threshold Voltage Relative to V Timer Starts when BAT FLOAT V < V BAT TRKL (Note 200mA BAT and BAT) OUT Rising NTC Voltage Hysteresis Hysteresis Falling NTC Voltage Hysteresis NTC BUS LTC3553 = 25°C, A MIN TYP 0.01 1 (Note 10) 0.01 0.1 0.1 4. 400 450 3.8 3.5 3.6 200 0 50 350 4 ...
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... LTC3553 POWER MANAGER ELECTRICAL CHARACTERISTICS The l denotes specifi cations that apply over the full operating temperature range, otherwise specifi cations are 5V 3.8V, HPWR = SUSP = BUCK_ON = LDO_ON = 0V, R BUS BAT SYMBOL PARAMETER Ideal Diode V Forward Voltage Detection FWD R Diode On-Resistance, Dropout ...
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... I = 150mA 3.8V LDO INLDO I = 150mA 2.5V LDO INLDO I = 75mA 1.8V LDO INLDO CONDITIONS (Notes (Note Pull- (Note PBSTAT I = 3mA PBSTAT LTC3553 = 25°C. A MIN TYP MAX UNITS l 1.65 5.5 V 2.5 2.6 V 2.8 2 780 800 820 mV 0.7 mV/V 0.025 mV/mA – 150 mA 300 ...
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... Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: The LTC3553 is guaranteed to meet performance specifi cations from 0°C to 85°C. Specifi cations over the –40°C to 85°C operating temperature range are assured by design, characterization and correlation with statistical process controls ...
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... BUS HPWR = 1.87k PROG 0 125 150 –75 –50 – 100 125 TEMPERATURE (°C) 3553 G07 LTC3553 T = 25°C, unless otherwise specifi ed. A Battery Drain Current vs Temperature 3.8V BAT STBY = 3.8V 16 REGULATORS LOAD = 0mA 14 BUCK AND LDO ONLY LDO ON ...
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... LTC3553 TYPICAL PERFORMANCE CHARACTERISTICS V Load Regulation FLOAT 4.204 4.202 4.200 4.198 4.196 4.194 4.192 0 50 100 150 200 250 300 I (mA) BAT Forward Voltage vs Ideal Diode Current 300 250 BUS 200 150 V BUS 100 200 400 600 800 I (mA) ...
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... BUCK (1.2V) 10mV/DIV (AC) 5mA I BUCK 100μA 50μs/DIV BUS V = 3.8V BAT 125 150 STBY = HIGH 3553 G25 LTC3553 T = 25°C, unless otherwise specifi ed. A Buck Switching Regulator 1.8V Output Effi ciency vs Load 100 STBY = 3. 100 1000 0 ...
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... LTC3553 TYPICAL PERFORMANCE CHARACTERISTICS Buck Regulator Switch Impedance vs Temperature 1.6 BVIN = 3.2V STBY = L 1.4 PMOS 1.2 1.0 NMOS 0.8 0.6 0.4 0.2 0 –75 –50 – 100 TEMPERATURE (°C) Regulator Output Transient During STBY Transition BUCK OUTPUT 1.2V AT 10mA 20mV/DIV (AC) LDO OUTPUT 3.3V AT 10mA 50mV/DIV (AC) HIGH STBY LOW 50μs/DIV ...
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... OUT 50mV/DIV (AC) LDO (3.3V) 100mV/DIV (AC) 100mA I LDO 1mA 50μs/DIV 3553 G40 BUS V = 3.8V BAT STBY = HIGH LTC3553 T = 25°C, unless otherwise specifi ed. A LDO Dropout Voltage 1.8V INLDO 300 –45°C 25°C 250 90°C 200 150 100 50 0 125 150 ...
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... LTC3553 PIN FUNCTIONS HPWR (Pin 1): High Power Logic Input. When this pin is low the input current limit is set to 100mA and when this pin is driven high it is set to 500mA. The SUSP pin needs to be low for the input current limit circuit to be enabled. ...
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... Output Voltage of the PowerPath Controller OUT and Input Voltage of the Battery Charger. The majority of the portable products should be powered from V LTC3553 will partition the available power between the external load on V and the internal battery charger. OUT Priority is given to the external load and any extra power is used to charge the battery ...
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... LTC3553 BLOCK DIAGRAM V 20 BUS HPWR 1 SUSP 19 BATTERY 15 NTC MONITOR CHRG 14 STBY 6 BUCK_ON 7 LDO_ON 5 PBSTAT SEQ 2 14 www.DataSheet.in INPUT CC/CV CURRENT CHARGER LIMIT EXTPWR UVLO 1.125MHz TEMP OSCILLATOR CHARGE STATUS PUSHBUTTON INTERFACE AND SEQUENCE LOGIC OSC 0. STBY 8 200mA BUCK DC/ ...
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... OUT Ideal Diode From BAT to V The LTC3553 has an internal ideal diode from BAT to V designed to respond quickly whenever V BAT. If the load increases beyond the input current limit, additional current will be pulled from the battery via the ideal diode. Furthermore, if power to V ...
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... BAT. The resistance of FWD the internal ideal diode is approximately 240mΩ. Suspend Mode When the SUSP pin is pulled high the LTC3553 enters suspend mode to comply with the USB specifi cation. In this mode, the power path between high impedance state to reduce the V to 15μ ...
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... CHRG pin is released (high impedance). The CHRG pin does not respond to the C/10 threshold if the LTC3553 reduces the charge current due www.DataSheet.in to excess load on the V OUT of charge indications due to insuffi ...
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... As the temperature drops, the resistance of the NTC thermistor rises. The LTC3553 is also designed to pause charging when the value of the NTC thermistor increases to 3.17 times the value of R25. For a Vishay curve 1 thermistor this resistance, 317k, corresponds to approximately 0° ...
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... BUS (NTC FALLING) 0.017 • V (NTC FALLING) Figure 2. NTC Thermistor Circuit With Additional Bias Resistor The trip points for the LTC3553’s temperature qualifi ca- tion are internally programmed at 0.35 • V threshold and 0.76 • V BUS Therefore, the hot trip point is set when: ...
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... Burst Mode operation to maintain high effi ciency. Applications with a near-zero-current sleep or memory keep-alive mode can command the LTC3553 buck regula- tor into a standby mode that maintains output regulation while drawing only 1.5μA quiescent current. Load capability drops to 10mA in this mode. ...
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... The application circuit commands the LTC3553 into and out of standby mode via the STBY pin logic input. Bringing the STBY pin high places the regulator into standby mode, while bringing it low returns it to Burst Mode operation ...
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... LTC3553 OPERATION Inductor value should be chosen based on the desired output voltage. See Table 1. Table 3 shows several induc- tors that work well with the step-down switching buck regulator. These inductors offer a good compromise in current rating, DCR and physical size. Consult each manu- facturer for detailed information on their entire selection of inductors ...
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... OUT to a voltage exceeding V INLDO , by choosing R1 LDO ⎛ ⎞ 0.8V • +1 ⎜ ⎟ LDO R2 ⎝ ⎠ V INLDO LDO 0 ENABLE MP 1 LDO R1 LDO_FB 0.8V R2 GND 3553 F04 Figure 4. LDO Application Circuit LTC3553 may result OUT LDO OUTPUT C OUT 3553f 23 ...
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... USB PowerPath V pin, to ensure proper operation. PUSHBUTTON INTERFACE State Diagram/Operation Figure 7 shows the LTC3553 pushbutton state diagram. Upon fi rst application of power, V nal power on reset (POR) signal places the pushbutton circuitry into the power-down (PDN1) state. One second ...
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... The state machine remains in the power-down state for one second, before automatically entering the power-off (POFF) state. This one second delay allows all LTC3553 generated supplies time to power down completely before they can be re-enabled. The same events used to exit the hard reset (HR) state are also used to exit the POFF state and enter the PUP2 state ...
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... ON pushbutton applications in the PUP1, PUP2 or PON states. Power-Up Via Applying External Power Figure 9 shows the LTC3553 powering up through ap- plication of external power (V pushbutton circuitry starts in the POFF or HR state with a battery connected and both regulators disabled. 100ms ...
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... LDO will power up. The pushbutton circuitry remains in the PON state. Powering up via asserting the BUCK_ON or LDO_ON pins > V and V – V > UVLO BUS BAT is useful for applications containing an always-on μC that’s not powered by the LTC3553 regulators. That μC can power 1 BAT BUS (PB) 0 ...
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... PDN2 state. In the PDN2 state a one second wait time is initiated after which the pushbutton circuitry enters the POFF state. During this one second time, the ON, BUCK_ON and LDO_ON inputs as well as external power application are ignored to allow all LTC3553 1 BAT 0 ...
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... BUCK_ON and LDO_ON pins would also go low, as depicted in Figure 12. If the external supply recovers after entering the PDN2 state such that V the LTC3553 will transition back into the PUP2 state once the PDN2 one second delay is complete. Following the state diagram, the transition from PDN2 to PUP2 in this case actually occurs via a brief visit to the POFF state ...
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... OPERATION Power-Up Sequencing Figure 14 shows the actual power-up sequencing of the LTC3553 with the SEQ pin held low. The regulators are both initially disabled (0V). Once the pushbutton has been applied (ON low) for 400ms, the buck is enabled. The buck slews up and enters regulation. The actual slew rate is con- ...
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... GND side of each capacitor should connect directly to the ground plane of the part. This capacitor provides the AC current to the internal power MOSFETs and their drivers important to minimize inductance from this capacitor to the pin of the LTC3553. Connect BVIN to V and V to its input supply through short low ...
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... R2 T 100k 32 www.DataSheet.in USB PowerPath With Li-Ion Battery (NTC Qualifi ed Charging) SYSTEM LOAD BUS OUT C3 C1 10μF 10μ CHRG NTC R3 LTC3553 16 17 PROG BAT + R PROG 1.87k 1 12 HPWR BVIN 11 19 SUSP V INLDO 10 5 LDO LDO_ON 2 SEQ ...
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... STBY 11 V INLDO 5 LDO_ON 10 3 LDO PBSTAT 4 ON PB1 9 LDO_FB GND LDO EN Li-Ion BATTERY 3.3V I UP1 2.05M 10μF R LO1 649k C5 2.2μF 1.2V CORE R C6 UP2 μC 332k 4.7μF R LO2 649k R3 100k PBSTAT LDO_ON STBY BUCK_ON SUSP HPWR 3553 TA03 LTC3553 1.8V MEMORY 3553f 33 ...
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... LTC3553 TYPICAL APPLICATION 4.35V TO 5.5V USB INPUT 34 www.DataSheet.in 3-Cell Alkaline/Lithium With PowerPath (Charger Disabled BUS OUT C3 10μ CHRG NTC LTC3553 17 BAT + 16 PROG R PROG 1.87k 1 12 BVIN HPWR 11 19 SUSP V INLDO 10 5 LDO_ON LDO 2 SEQ 9 LDO_FB 6 STBY L1 10μH ...
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... 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. LTC3553 BOTTOM VIEW—EXPOSED PAD PIN 1 NOTCH 0.35 45° ...
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... LTC3553 RELATED PARTS PART DESCRIPTION NUMBER LTC3455 Dual DC/DC Converter with USB Power Manager and Li-Ion Battery Charger LTC3456 2-Cell, Multioutput DC/DC Converter with USB Power Manager LTC3550 Dual Input USB/AC Adapter Li-Ion Battery Charger with Adjustable Output 600mA Buck Converter LTC3552 Standalone Linear Li-Ion Battery Charger ...