LTC1709EG-85 Linear Technology, LTC1709EG-85 Datasheet
LTC1709EG-85
Specifications of LTC1709EG-85
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LTC1709EG-85 Summary of contents
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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 registered trademarks of Linear Technology Corporation. + TG1 IN S BOOST1 0 ...
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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, (g • 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 ...
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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-85 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) 170985 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) 170985 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 – 1.6V OUT –12 –11 –10 –9 –8 125 –50 – 100 TEMPERATURE ( C) 170985 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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LTC1709-85 U OPERATIO (Refer to Functional Diagram) Main Control Loop The LTC1709-85 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 a minimum of 4.7 F tantalum or electrolytic capacitor. An additional 1 F ceramic capacitor placed very close to the IC is recommended due to the extremely high instanta- neous currents required ...
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U U APPLICATIO S I FOR ATIO Output Voltage Programming The output voltage is digitally programmed as defined in Table 1 using the VID25mV to VID3 logic input pins. The VID logic inputs program a precision, 0.25% internal feedback resistive ...
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LTC1709- APPLICATIO S I FOR ATIO The time for the output current to ramp up is then IRAMP pulling the RUN/SS ...
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U U APPLICATIO S I FOR ATIO external and internal oscillators. This type of phase detec- tor will not lock up on input frequencies close to the harmonics of the VCO center frequency. The PLL hold-in range ...
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LTC1709- APPLICATIO S I FOR ATIO FCB Pin Operation The following table summarizes the possible states avail- able on the FCB pin: Table 2 FCB Pin Condition 0V to 0.75V Forced Continuous (Current Reversal Allowed—Burst Inhibited) 0.85V < ...
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U U APPLICATIO S I FOR ATIO 3) INTV current is the sum of the MOSFET driver and CC control currents. The MOSFET driver current results from switching the gate capacitance of the power MOSFETs. Each time a MOSFET gate ...
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LTC1709- APPLICATIO S I FOR ATIO loop and is the filtered and compensated control loop response. The gain of the loop will be increased by increasing R and the bandwidth of the loop will be C increased by ...
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U U APPLICATIO S I FOR ATIO The duty factor for this application is Using Figure 4, the RMS ripple current will be (20A)(0.23) ...
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LTC1709- APPLICATIO S I FOR ATIO pin (PGND) and the signal ground pin (SGND). This technique keeps inherent signals generated by high cur- rent pulses from taking alternate current paths that have finite impedances during the total period ...
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U U APPLICATIO S I FOR ATIO BOLD LINES INDICATE HIGH, SWITCHING CURRENT LINES. KEEP LINES TO A MINIMUM LENGTH. Figure 8. Instantaneous Current Path Flow in a Multiple Phase Switching Regulator W ...
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LTC1709- APPLICATIO S I FOR ATIO SINGLE PHASE CIN I COUT SW1 V SW2 CIN I COUT Figure 9. Single and 2-Phase Current Waveforms DUAL PHASE L1 L2 ...
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... FLASH SHALL NOT EXCEED .254mm (.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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... PolyPhase Step-Down Synchronous Controller LTC3730 3-Phase, 5-Bit Intel Mobile VID Synchronous Step-Down Controller LTC3732 3-Phase Step-Down Synchronous Controller (VRM 9.0/9.1) Adaptive Power and No R are trademarks of Linear Technology Corporation. SENSE Linear Technology Corporation 28 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 www ...