LTC3890EGN-1 LINER [Linear Technology], LTC3890EGN-1 Datasheet
LTC3890EGN-1
Related parts for LTC3890EGN-1
LTC3890EGN-1 Summary of contents
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FEATURES n Wide V Range 60V (65V Abs Max Low Operating I : 50μA (One Channel On Wide Output Voltage Range: 0.8V ≤ DCR Current Sensing SENSE n Out-of-Phase Controllers ...
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... ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL LTC3890EGN-1#PBF LTC3890EGN-1#TRPBF LTC3890IGN-1#PBF LTC3890IGN-1#TRPBF Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. *The temperature grade is identifi label on the shipping container. Consult LTC Marketing for information on non-standard lead based fi nish parts. ...
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ELECTRICAL CHARACTERISTICS junction temperature range, otherwise specifi cations are at T SYMBOL PARAMETER g Transconductance Amplifi m1 Input DC Supply Current Q Pulse Skip or Forced Continuous Mode (One Channel On) Pulse Skip or Forced Continuous ...
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LTC3890-1 ELECTRICAL CHARACTERISTICS junction temperature range, otherwise specifi cations are at T SYMBOL PARAMETER V INTV Load Regulation LDOEXT CC V EXTV Switchover Voltage EXTVCC CC V EXTV Hysteresis LDOHYS CC Oscillator and Phase-Locked Loop f Programmable Frequency 25kΩ f ...
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TYPICAL PERFORMANCE CHARACTERISTICS Effi ciency and Power Loss vs Output Current 100 V = 12V IN BURST EFFICIENCY V = 3.3V 90 OUT 80 70 CCM LOSS 60 50 BURST LOSS PULSE-SKIPPING 40 LOSS 30 CCM EFFICIENCY 20 PULSE-SKIPPING 10 ...
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LTC3890-1 TYPICAL PERFORMANCE CHARACTERISTICS Total Input Supply Current vs Input Voltage 300 250 200 300μA 150 100 NO LOAD INPUT VOLTAGE (V) 38901 G10 Maximum ...
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TYPICAL PERFORMANCE CHARACTERISTICS TRACK/SS Pull-Up Current vs Temperature 1.10 1.05 1.00 0.95 0.90 –45 – 105 TEMPERATURE (°C) 38901 G19 – SENSE Pin Total Input Bias Current vs Temperature < INTV – 0.5V ...
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LTC3890-1 PIN FUNCTIONS ITH1, ITH2 (Pin 1, Pin 13): Error Amplifi er Outputs and Switching Regulator Compensation Points. Each associ- ated channel’s current comparator trip point increases with this control voltage (Pin 2, Pin 12): Receives the ...
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PIN FUNCTIONS BG1, BG2 (Pin 23, Pin 18): High Current Gate Drives for Bottom (Synchronous) N-Channel MOSFETs. Voltage swing at these pins is from ground to INTV BOOST1, BOOST2 (Pin 24, Pin 17): Bootstrapped Supplies to the Topside Floating Drivers. ...
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LTC3890-1 FUNCTIONAL DIAGRAM PGOOD1 + 0.88V – V FB1 + – 0.72V 20μA FREQ VCO C LP SYNC DET PLLIN/MODE 100k V IN EXTV CC 5.1V 5.1V LDO LDO – 4.7V SGND INTV CC 10 DUPLICATE FOR ...
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OPERATION (Refer to the Functional Diagram) Main Control Loop The LTC3890-1 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 ...
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LTC3890-1 OPERATION (Refer to the Functional Diagram) Light Load Current Operation (Burst Mode Operation, Pulse Skipping, or Forced Continuous Mode) (PLLIN/MODE Pin) The LTC3890-1 can be enabled to enter high effi ciency Burst Mode operation, constant frequency pulse skipping mode, ...
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OPERATION (Refer to the Functional Diagram) If the PLLIN/MODE pin is not being driven by an external clock source, the FREQ pin can be tied to SGND, tied to INTV or programmed through an external resistor. CC Tying FREQ to ...
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LTC3890-1 OPERATION (Refer to the Functional Diagram) together. The result is a signifi cant reduction in total RMS input current, which in turn allows less expensive input capacitors to be used, reduces shielding requirements for EMI and improves real world ...
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APPLICATIONS INFORMATION The Typical Application on the fi rst page is a basic LTC3890-1 application circuit. LTC3890-1 can be confi g- ured to use either DCR (inductor resistance) sensing or low value resistor sensing. The choice between the two current ...
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LTC3890-1 APPLICATIONS INFORMATION Low Value Resistor Current Sensing A typical sensing circuit using a discrete resistor is shown in Figure 4a chosen based on the required SENSE output current. The current comparator has a maximum threshold V . ...
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APPLICATIONS INFORMATION The equivalent resistance R1 scaled to the room temperature inductance and maximum DCR DCR at • 1 ° The sense resistor values ...
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LTC3890-1 APPLICATIONS INFORMATION The peak-to-peak drive levels are set by the INTV voltage. This voltage is typically 5.1V during start-up (see EXTV Pin Connection). Consequently, logic-level CC threshold MOSFETs must be used in most applications. Pay close attention to the ...
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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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LTC3890-1 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 LTC3890-1 ...
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APPLICATIONS INFORMATION LDO regulate INTV to 5.1V. Each of these can supply a CC peak current of 50mA and must be bypassed to ground with a minimum of 4.7μF ceramic capacitor. No matter what type of bulk capacitor is used, ...
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LTC3890-1 APPLICATIONS INFORMATION C IN BAT85 V IN MTOP TG1 1/2 LTC3890-1 L EXTV SW CC MBOT D BG1 PGND Figure 9. Capacitive Charge Pump for EXTV Topside MOSFET Driver Supply (C External bootstrap capacitors connected to the ...
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APPLICATIONS INFORMATION Phase-Locked Loop and Frequency Synchronization The LTC3890-1 has an internal phase-locked loop (PLL) comprised of a phase frequency detector, a lowpass fi lter, and a voltage-controlled oscillator (VCO). This allows the turn-on of the top MOSFET of controller ...
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LTC3890-1 APPLICATIONS INFORMATION The minimum on-time for the LTC3890-1 is approximately 90ns. However, as the peak sense voltage decreases the minimum on-time gradually increases up to about TBDns. This is of particular concern in forced continuous applica- tions with low ...
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APPLICATIONS INFORMATION during the design phase. The internal battery and fuse resistance losses can be minimized by making sure that C has adequate charge storage and very low ESR at IN the switching frequency. A 25W supply will typically require ...
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LTC3890-1 APPLICATIONS INFORMATION Design Example As a design example for one channel, assume V 12V(nominal 22V (max OUT V = 75mV and f = 350kHz. SENSE(MAX) The inductance value is chosen fi rst based on a ...
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APPLICATIONS INFORMATION leads and PC trace lengths. The output capacitor (–) terminals should be connected as close as possible to the (–) terminals of the input capacitor by placing the capacitors next to each other and away from the Schottky ...
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LTC3890-1 APPLICATIONS INFORMATION and possibly BG connections and the sensitive voltage and current pins. The capacitor placed across the current sensing pins needs to be placed immediately adjacent to the pins of the IC. This capacitor helps to minimize the ...
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APPLICATIONS INFORMATION ITH1 V SENSE1 SENSE1 FREQ f IN PLLIN/MODE RUN1 RUN2 SGND SENSE2 SENSE2 V ITH2 TRACK/SS2 Figure 11. Recommended Printed Circuit Layout Diagram TRACK/SS1 PGOOD1 FB1 + TG1 – SW1 LTC3890 BOOST1 BG1 V IN PGND ...
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LTC3890-1 APPLICATIONS INFORMATION BOLD LINES INDICATE HIGH SWITCHING CURRENT. KEEP LINES TO A MINIMUM LENGTH. 30 SW1 L1 R SENSE1 D1 C OUT1 SW2 L2 R SENSE2 D2 C OUT2 Figure 12. Branch Current ...
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TYPICAL APPLICATIONS R B1 100k R A1 31.6k C 100pF ITH1A R C 1000pF ITH1 ITH1 34.8k C 0.01μF SS1 R FREQ 41.2k C 0.01μF SS2 R C 470pF ITH2 ITH2 34. 10. 100k MTOP1, MTOP2, ...
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LTC3890-1 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, ...
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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 MTOP1, MTOP2, ...
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LTC3890-1 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 100k ...
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PACKAGE DESCRIPTION .254 MIN .0165 .0015 RECOMMENDED SOLDER PAD LAYOUT .0075 – .0098 (0.19 – 0.25) .016 – .050 (0.406 – 1.270) NOTE: 1. CONTROLLING DIMENSION: INCHES INCHES 2. DIMENSIONS ARE IN (MILLIMETERS) 3. DRAWING NOT TO SCALE * DIMENSION ...
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LTC3890-1 TYPICAL APPLICATION + SENSE1 1nF 100k – SENSE1 R A1 6.98k V FB1 C 100pF ITH1A R C 470pF ITH1 ITH1 34.8k ITH1 C 0.01μF LTC3890-1 SS1 TRACK/SS1 PLLIN/MODE SGND EXTV CC RUN1 R FREQ RUN2 ...