LTC3890EGN-1#PBF Linear Technology, LTC3890EGN-1#PBF Datasheet
LTC3890EGN-1#PBF
Specifications of LTC3890EGN-1#PBF
Related parts for LTC3890EGN-1#PBF
LTC3890EGN-1#PBF Summary of contents
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... For a leaded package version (28-lead Narrow SSOP), see the LTC3890-1 data sheet. L, LT, LTC, LTM, Burst Mode and OPTI-LOOP are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 5481178, 5705919, 5929620, 6100678, 6144194, 6177787, 6304066, 6580258, 7230497 ...
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LTC3890 ABSOLUTE MAXIMUM RATINGS (Note 1) Input Supply Voltage (V ) ......................... –0.3V to 65V IN Topside Driver Voltages BOOST1, BOOST2 .................................–0.3V to 71V Switch Voltage (SW1, SW2) ......................... –5V to 65V (BOOST1-SW1), (BOOST2-SW2) ................ –0. RUN1, RUN2 ...
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ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T SYMBOL PARAMETER I Feedback Current FB1,2 V Reference Voltage Line Regulation REFLNREG V Output Voltage Load Regulation LOADREG g Transconductance Amplifier g m1 Input DC Supply Current Q Pulse-Skipping ...
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LTC3890 ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T SYMBOL PARAMETER BG/TG t Bottom Gate Off to Top Gate On Delay 1D Top Switch-On Delay Time t Minimum On-Time ON(MIN) INTV Linear Regulator CC V Internal V Voltage INTVCCVIN ...
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TYPICAL PERFORMANCE CHARACTERISTICS Efficiency and Power Loss vs Output Current 100 V = 12V BURST EFFICIENCY 3.3V 90 OUT 80 70 CCM LOSS 60 50 BURST LOSS PULSE-SKIPPING 40 LOSS 30 CCM EFFICIENCY 20 PULSE-SKIPPING 10 EFFICIENCY ...
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LTC3890 TYPICAL PERFORMANCE CHARACTERISTICS Total Input Supply Current vs Input Voltage 300 V = 3.3V OUT FIGURE 13 CIRCUIT 250 200 300μA LOAD 150 100 NO LOAD ...
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TYPICAL PERFORMANCE CHARACTERISTICS TRACK/SS Pull-Up Current vs Temperature 1.10 1.05 1.00 0.95 0.90 –75 –50 – 100 125 150 TEMPERATURE (°C) 3890 G19 – SENSE Pin Total Input Bias Current vs Temperature 800 700 V > ...
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LTC3890 PIN FUNCTIONS – – SENSE1 , SENSE2 (Pin 1, Pin 9): The (–) Input to the Differential Current Comparators. When greater than – INTV – 0.5V, the SENSE pin supplies current to the CC current comparator. FREQ (Pin 2): ...
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PIN FUNCTIONS TG1, TG2 (Pin 26, Pin 15): High Current Gate Drives for Top N-Channel MOSFETs. These are the outputs of float- ing drivers with a voltage swing equal to INTV superimposed on the switch node voltage SW. PGOOD1, PGOOD2 ...
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LTC3890 FUNCTIONAL DIAGRAM PGOOD1 PHASMD + 0.88V 27 3 – V FB1 + – 0.72V PGOOD2 + 0.88V 14 – V FB2 + – 0.72V 20μA FREQ 2 VCO C LP SYNC DET PLLIN/MODE 5 100k I LIM CURRENT 28 ...
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OPERATION (Refer to the Functional Diagram) Main Control Loop The LTC3890 uses a constant frequency, current mode step-down architecture with the two controller channels operating 180 degrees out-of-phase. During normal op- eration, each external top MOSFET is turned on when ...
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LTC3890 OPERATION (Refer to the Functional Diagram) Light Load Current Operation (Burst Mode Operation, Pulse-Skipping or Forced Continuous Mode) (PLLIN/MODE Pin) The LTC3890 can be enabled to enter high efficiency Burst Mode operation, constant frequency pulse-skipping mode, or forced continuous ...
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OPERATION (Refer to the Functional Diagram) A phase-locked loop (PLL) is available on the LTC3890 to synchronize the internal oscillator to an external clock source that is connected to the PLLIN/MODE pin. The LTC3890’s phase detector adjusts the voltage (through ...
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LTC3890 OPERATION (Refer to the Functional Diagram) With 2-phase operation, the two channels of the dual switching regulator are operated 180 degrees out-of-phase. This effectively interleaves the current pulses drawn by the switches, greatly reducing the overlap time where they ...
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APPLICATIONS INFORMATION The Typical Application on the first page is a basic LTC3890 application circuit. LTC3890 can be configured to use either DCR (inductor resistance) sensing or low value resistor sensing. The choice between the two current sensing schemes is ...
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LTC3890 APPLICATIONS INFORMATION placed close to the switching node, to prevent noise from coupling into sensitive small-signal nodes. Low Value Resistor Current Sensing A typical sensing circuit using a discrete resistor is shown in Figure 4a chosen based ...
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APPLICATIONS INFORMATION The equivalent resistance R1 scaled to the room temperature inductance and maximum DCR DCR at 20°C • C1 The sense resistor values are: R1|| R2 R1• R1= ; ...
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LTC3890 APPLICATIONS INFORMATION The peak-to-peak drive levels are set by the INTV This voltage is typically 5.1V during start-up (see EXTV Pin Connection). Consequently, logic-level threshold MOSFETs must be used in most applications. Pay close attention to the BV specification ...
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APPLICATIONS INFORMATION RMS capacitor current requirement. Increasing the out- put current drawn from the other controller will actually decrease the input RMS ripple current from its maximum value. The out-of-phase technique typically reduces the input capacitor’s RMS ripple current by ...
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LTC3890 APPLICATIONS INFORMATION Tracking and Soft-Start (TRACK/SS Pins) The start-up of each V is controlled by the voltage on OUT the respective TRACK/SS pin. When the voltage on the TRACK/SS pin is less than the internal 0.8V reference, the LTC3890 ...
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APPLICATIONS INFORMATION INTV Regulators CC The LTC3890 features two separate internal P-channel low dropout linear regulators (LDO) that supply power at the INTV pin from either the V supply pin or the EXTV CC IN pin depending on the connection ...
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LTC3890 APPLICATIONS INFORMATION The following list summarizes the four possible connec- tions for EXTV : CC 1. EXTV Grounded. This will cause INTV CC from the internal 5.1V regulator resulting in an efficiency penalty 10% at high ...
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APPLICATIONS INFORMATION Fault Conditions: Current Limit and Current Foldback The LTC3890 includes current foldback to help limit load current when the output is shorted to ground. If the output voltage falls below 70% of its nominal output level, then the ...
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LTC3890 APPLICATIONS INFORMATION Note that the LTC3890 can only be synchronized to an external clock whose frequency is within range of the LTC3890’s internal VCO, which is nominally 55kHz to 1MHz. This is guaranteed to be between 75kHz and 850kHz. ...
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APPLICATIONS INFORMATION Efficiency Considerations The percent efficiency of a switching regulator is equal to the output power divided by the input power times 100 often useful to analyze individual losses to determine what is limiting the efficiency and ...
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LTC3890 APPLICATIONS INFORMATION Checking Transient Response The regulator loop response can be checked by looking at the load current transient response. Switching regulators take several cycles to respond to a step in DC (resistive) load current. When a load step ...
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APPLICATIONS INFORMATION Design Example As a design example for one channel, assume V (nominal 22V (max OUT V = 75mV and f = 350kHz. SENSE(MAX) The inductance value is chosen first based on a 30% ripple ...
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LTC3890 APPLICATIONS INFORMATION ITH1 V FB1 R1* SENSE1 C1* SENSE1 FREQ PHASMD CLKOUT f IN PLLIN/MODE RUN1 RUN2 SGND SENSE2 C2* SENSE2 R2* V FB2 ITH2 TRACK/SS2 *R1, R2, C1, C2, D1, D2 ARE OPTIONAL. Figure 11. Recommended Printed Circuit ...
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APPLICATIONS INFORMATION BOLD LINES INDICATE HIGH SWITCHING CURRENT. KEEP LINES TO A MINIMUM LENGTH. SW1 L1 R SENSE1 D1 C OUT1 SW2 L2 R SENSE2 D2 C OUT2 Figure 12. Branch Current Waveforms LTC3890 ...
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LTC3890 APPLICATIONS INFORMATION PC Board Layout Checklist When laying out the printed circuit board, the following checklist should be used to ensure proper operation of the IC. These items are also illustrated graphically in the layout diagram of Figure 11. ...
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APPLICATIONS INFORMATION PC Board Layout Debugging Start with one controller time helpful to use a DC-50MHz current probe to monitor the current in the inductor while testing the circuit. Monitor the output switch- ing node ...
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LTC3890 TYPICAL APPLICATIONS R A1 31.6k C ITH1A C 1000pF ITH1 C 0.01μF SS1 R FREQ 41.2k C 0.01μF SS2 C 470pF ITH2 R A2 10.5k MTOP1, MTOP2, MBOT1, MBOT2: RJK0651DPB L1: COILCRAFT SER1360-472KL L2: COILCRAFT SER1360-802KL C : SANYO ...
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TYPICAL APPLICATIONS R B1 100k R A1 10.5k C 100pF ITH1A R 34.8k ITH1 C ITH1 C 0.01μF SS1 470pF INTV R CC MODE 100k R RUN V OUT 1000k 41.2k FREQ C ITH2 100pF MTOP1, MTOP2, ...
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LTC3890 TYPICAL APPLICATIONS R B1 100k R A1 6.98k C 100pF ITH1A R C 470pF ITH1 ITH1 34.8k C 0.01μF SS1 R FREQ 41.2k C 0.01μF SS2 R C 470pF ITH2 ITH2 20k R A2 18. 100k 34 ...
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TYPICAL APPLICATIONS R B1 487k C 33pF 16.9k C 100pF ITH1A R C 680pF ITH1 ITH1 46k C 0.01μF SS1 R FREQ 60k C 0.01μF SS2 R C 470pF ITH2 ITH2 20k R A2 18. ...
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LTC3890 PACKAGE DESCRIPTION 5.50 0.05 4.10 0.05 3.45 0.05 3.50 REF (4 SIDES) 3.45 0.05 RECOMMENDED SOLDER PAD LAYOUT APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED 5.00 0.10 (4 SIDES) PIN 1 TOP MARK (NOTE 6) NOTE: 1. ...
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... Added MP-grade and H-grade. Changes reflected throughout the data sheet. 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. ...
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... TSSOP-20E, 3mm × 4mm QFN-20 OUT ≤ 38V, IN ≤ 24V 50μA/170μA OUT Q ≤ 36V, IN ≤ 10V 30μA/80μA OUT Q ≤ 100V, IN ≤ 0.93V , SSOP-28 OUT IN ≤ 38V 24V 60V IN OUT(BUCK) OUT(BOOST) LT 0111 REV A • PRINTED IN USA © LINEAR TECHNOLOGY CORPORATION 2010 3890fa ...