LTC1709EG-7 Linear Technology, LTC1709EG-7 Datasheet

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... OPTI-LOOP compensation allows the transient response to be optimized for a wide range of output capacitors and ESR values. , LTC and LT are registered trademarks of Linear Technology Corporation. OPTI-LOOP and Burst Mode are trademarks of Linear Technology Corporation ...

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... Voltage: 1. 3.6V to 30V (Note 4) IN Measured at FCB pin Measured at V EAIN V Ramping Down 1.2V, Sink/Source 5 A (Note 1.2V Ext Load) (Note ORDER PART TOP VIEW NUMBER TG1 LTC1709EG SW1 4 33 BOOST1 BG1 7 30 EXTV INTV PGND 10 27 BG2 11 26 BOOST2 12 25 ...

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ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T SYMBOL PARAMETER I Input DC Supply Current Q Normal Mode Shutdown I Soft-Start Charge Current RUN/SS V RUN/SS Pin ON Arming RUN/SS V RUN/SS Pin Latchoff Arming RUN/SSLO I RUN/SS Discharge ...

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... Input Resistance IN Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: The LTC1709EG-7 is guaranteed to meet performance specifications from Specifications over the – operating temperature range are assured by design, characterization and correlation with statistical process controls. ...

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W U TYPICAL PERFOR A CE CHARACTERISTICS Supply Current vs Input Voltage and Mode 1000 ON 800 600 400 200 SHUTDOWN INPUT VOLTAGE (V) 17097 G04 Internal 5V LDO Line Reg ...

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LTC1709 TYPICAL PERFOR A CE CHARACTERISTICS Load Regulation 0.0 FCB = 15V IN FIGURE 1 –0.1 –0.2 –0.3 –0 LOAD CURRENT (A) 17097 G13 Maximum Current Sense Threshold vs Temperature ...

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W U TYPICAL PERFOR A CE CHARACTERISTICS Current Sense Pin Input Current vs Temperature OUT 125 –50 – 100 TEMPERATURE ( C) 17097 G20 Undervoltage Lockout vs ...

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LTC1709 CTIO S PLLFLTR (Pin 5): The phase-locked loop’s lowpass filter is tied to this pin. Alternatively, this pin can be driven with voltage source to vary the frequency of the ...

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CTIO AL DIAGRA PLLIN PHASE DET f IN 50k PLLFLTR CLK1 OSCILLATOR CLK2 TO SECOND CHANNEL PGOOD – 0.86V + EAIN – + 0.74V – – ...

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LTC1709-7 U OPERATIO (Refer to Functional Diagram) Main Control Loop The LTC1709-7 uses a constant frequency, current mode step-down architecture with the two output stages oper- ating 180 degrees out of phase. During normal operation, each top MOSFET is turned ...

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U OPERATIO (Refer to Functional Diagram) Frequency Synchronization The phase-locked loop allows the internal oscillator to be synchronized to an external source via the PLLIN pin. The output of the phase detector at the PLLFLTR pin is also the DC ...

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... The inductor value has a direct effect on ripple current. The inductor ripple current I decreases with higher inductance or frequency and increases with higher where f is the individual output stage operating frequency. PolyPhase is a registered trademark of Linear Technology Corporation. 2.5 2.0 1.5 1.0 0.5 0 ...

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U U APPLICATIO S I FOR ATIO In a 2-phase converter, the net ripple current seen by the output capacitor is much smaller than the individual inductor ripple currents due to ripple cancellation. The details on how to calculate the ...

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LTC1709 APPLICATIO S I FOR ATIO factors for the top and bottom MOSFETs of each output stage are given by: V OUT Main Switch Duty Cycle V IN Synchronous Switch Duty Cycle The MOSFET power dissipations at maximum ...

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U U APPLICATIO S I FOR ATIO 0.6 0.5 0.4 1-PHASE 2-PHASE 0.3 0.2 0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 DUTY FACTOR (V /V OUT Figure 4. Normalized RMS Input Ripple Current vs Duty Factor for 1 and ...

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LTC1709 APPLICATIO S I FOR ATIO 50mA peak and must be bypassed to power ground with a minimum of 4.7 F tantalum or electrolytic capacitor. An additional 1 F ceramic capacitor placed very close to the IC is ...

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U U APPLICATIO S I FOR ATIO OPTIONAL EXTV CC + CONNECTION 5V < V < SEC TG1 LTC1709-7 N-CH EXTV CC SW1 R6 FCB BG1 N-CH R5 PGND Figure 5a. Secondary Output Loop with ...

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LTC1709 APPLICATIO S I FOR ATIO Table 1. VID Output Voltage Programming VID4 VID3 VID2 VID1 ...

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U U APPLICATIO S I FOR ATIO RUN/ *OPTIONAL TO DEFEAT OVERCURRENT LATCHOFF Figure 6. RUN/SS Pin Interfacing Fault Conditions: Overcurrent Latchoff The RUN/SS pin also provides the ability ...

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LTC1709 APPLICATIO S I FOR ATIO 2.4V PHASE DETECTOR EXTERNAL OSC PLLIN DIGITAL PHASE/ FREQUENCY DETECTOR 50k Figure 7. Phase-Locked Loop Block Diagram If the external frequency ( greater than the oscil- PLLIN lator frequency f ...

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U U APPLICATIO S I FOR ATIO The secondary output voltage V SEC shown in Figure 5a by the turns ratio N of the transformer SEC OUT However, if the controller goes into Burst Mode ...

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LTC1709 APPLICATIO S I FOR ATIO synchronous MOSFET. If the two MOSFETs have approxi- mately the same R , then the resistance of one DS(ON) MOSFET can simply be summed with the resistances and ...

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U U APPLICATIO S I FOR ATIO (from 0 times their suggested values) to optimize transient response once the final PC layout is done and the particular output capacitor type and value have been determined. The output capacitors ...

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LTC1709 APPLICATIO S I FOR ATIO A 1.5 H inductor will produce 27% ripple current. The peak inductor current will be the maximum DC value plus one half the ripple current, or 11.5A. The minimum on- time occurs ...

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U U APPLICATIO S I FOR ATIO PC Board Layout Checklist When laying out the printed circuit board, the following checklist should be used to ensure proper operation of the LTC1709-7. These items are also illustrated graphically in the layout ...

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LTC1709 APPLICATIO S I FOR ATIO BOLD LINES INDICATE HIGH, SWITCHING CURRENT LINES. KEEP LINES TO A MINIMUM LENGTH. Figure 10. Instantaneous Current Path Flow in a Multiple Phase Switching Regulator ...

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... FLASH SHALL NOT EXCEED 0.254mm (0.010") PER SIDE 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 represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. ...

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... LTC1709-8/LTC1709-9 2-Phase High Efficiency Controller with 5-Bit VID and Power Good LTC1735 High Efficiency Synchronous Step-Down Controller LTC1736 High Efficiency Synchronous Step-Down Controller with 5-Bit VID Adaptive Power is a trademark of Linear Technology Corporation. Linear Technology Corporation 28 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 www.linear-tech.com ...