LTC3850EUFD#TRPBF Linear Technology, LTC3850EUFD#TRPBF Datasheet
LTC3850EUFD#TRPBF
Specifications of LTC3850EUFD#TRPBF
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LTC3850EUFD#TRPBF Summary of contents
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... Battery-Operated Digital Devices n DC Power Distribution Systems n L, LT, LTC, LTM, OPTI-LOOP and Burst Mode 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. TYPICAL APPLICATION High Efficiency Dual 3 ...
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LTC3850/LTC3850-1 ABSOLUTE MAXIMUM RATINGS Input Supply Voltage (V ) ......................... 28V to –0.3V IN Input Supply Voltage ( LTC3850I Only ....................................... 30V to –0.3V Input Supply Transient Voltage (V IN INTV ≥ 5V, LTC3850I Only ................... 34V to ...
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... LTC3850IGN#PBF LTC3850IGN#TRPBF LTC3850IGN-1#PBF LTC3850IGN-1#TRPBF LTC3850EUF#PBF LTC3850EUF#TRPBF LTC3850EUFD#PBF LTC3850EUFD#TRPBF LTC3850IUF#PBF LTC3850IUF#TRPBF LTC3850IUFD#PBF LTC3850IUFD#TRPBF Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: ...
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LTC3850/LTC3850-1 ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T SYMBOL PARAMETER Main Control Loops V Regulated Feedback Voltage FB1,2 I Feedback Current FB1,2 V Reference Voltage Line Regulation REFLNREG V Output Voltage Load Regulation LOADREG g Transconductance Amplifier g ...
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ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T SYMBOL PARAMETER Oscillator and Phase-Locked Loop f Nominal Frequency NOM f Lowest Frequency LOW f Highest Frequency HIGH R MODE/PLLIN Input Resistance MODE/PLLIN I Phase Detector Output Current FREQ Sinking Capability ...
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LTC3850/LTC3850-1 TYPICAL PERFORMANCE CHARACTERISTICS Load Step (Burst Mode Operation) I LOAD 2A/DIV 200mA TO 2. 2A/DIV V OUT 100mV/DIV AC COUPLED 40µs/DIV CIRCUIT OF FIGURE 12V 1.8V IN OUT Load Step (Pulse-Skipping Mode) ...
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TYPICAL PERFORMANCE CHARACTERISTICS Tracking Up and Down with External Ramp TK/SS1 TK/SS2 2V/DIV V OUT1 3.3V 3Ω LOAD 1V/DIV V OUT2 1.8V 1.5Ω LOAD 1V/DIV 38501 G10 10ms/DIV Current Sense Threshold vs I Voltage INTV LIM ...
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LTC3850/LTC3850-1 TYPICAL PERFORMANCE CHARACTERISTICS Shutdown (RUN) Threshold vs Temperature 1.5 1.4 1.3 ON 1.2 OFF 1.1 1.0 –50 – TEMPERATURE (°C) 38501 G18 Undervoltage Lockout Threshold (INTV ) vs Temperature RISING 3 FALLING ...
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PIN FUNCTIONS (GN/UF/UFD) RUN1, RUN2 (Pins 1, 13/Pins 26, 9/Pins 27, 10): Run Control Inputs. A voltage above 1.2V on either pin turns on the IC. However, forcing either of these pins below 1.2V causes the IC to shut down ...
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LTC3850/LTC3850-1 PIN FUNCTIONS MODE/PLLIN (Pin 27/Pin 24/Pin 25): Force Continuous Mode, Burst Mode, or Pulse-Skipping Mode Selection Pin and External Synchronization Input to Phase Detector Pin. Connect this pin to SGND to force both channels into the continuous mode of ...
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OPERATION Main Control Loop The LTC3850 is a constant-frequency, current mode step- down controller with two channels operating 180 degrees out-of-phase. During normal operation, each top MOSFET is turned on when the clock for that channel sets the RS latch, ...
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LTC3850/LTC3850-1 OPERATION When a controller is enabled for Burst Mode operation, the peak current in the inductor is set to approximately one-third of the maximum sense voltage even though the voltage on the I pin indicates a lower value. If ...
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APPLICATIONS INFORMATION The Typical Application on the first page is a basic LTC3850 application circuit. LTC3850 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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LTC3850/LTC3850-1 APPLICATIONS INFORMATION close to the switching node, to prevent noise from coupling into sensitive small-signal nodes. The capacitor C1 should be placed close to the IC pins. Low Value Resistors Current Sensing A typical sensing circuit using a discrete ...
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APPLICATIONS INFORMATION V SENSE 20mV/DIV 500ns/DIV Figure 3. Voltage Waveform Measured Directly Across the Sense Resistor. V SENSE 20mV/DIV 500ns/DIV Figure 4. Voltage Waveform Measured After the Sense Resistor Filter 1000pF , R F Inductor DCR Sensing For ...
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LTC3850/LTC3850-1 APPLICATIONS INFORMATION Ensure that R1 has a power rating higher than this value. If high efficiency is necessary at light loads, consider this power loss when deciding whether to use DCR sensing or sense resistors. Light load power loss ...
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APPLICATIONS INFORMATION voltage and maximum output current. Miller capacitance can be approximated from the gate charge curve MILLER usually provided on the MOSFET manufacturers’ data sheet equal to the increase in gate charge MILLER along the ...
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LTC3850/LTC3850-1 APPLICATIONS INFORMATION selected mode once TK/SS > 0.74V. The output ripple is minimized during the 100mV forced continuous mode window ensuring a clean PGOOD signal. When the channel is configured to track another supply, the feedback voltage of the ...
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APPLICATIONS INFORMATION TIME (5a) Coincident Tracking Figure 5. Two Different Modes of Output Voltage Tracking V OUT1 TK/SS2 PIN R4 R2 (6a) Coincident Tracking Setup Figure 6. Setup for Coincident and Ratiometric Tracking V OUT1 V OUT2 ...
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LTC3850/LTC3850-1 APPLICATIONS INFORMATION exceeded. The INTV current, which is dominated by the CC gate charge current, may be supplied by either the 5V linear regulator or EXTV . When the voltage on the EXTV CC is less than 4.7V, the ...
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APPLICATIONS INFORMATION turns on the topside switch. The switch node voltage, SW, rises to V and the BOOST pin follows. With the topside IN MOSFET on, the boost voltage is above the input supply ...
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LTC3850/LTC3850-1 APPLICATIONS INFORMATION suggested. A 2.2Ω – 10Ω resistor placed between C (C1) and the V pin provides further isolation between IN the two channels. The selection driven by the effective series OUT resistance (ESR). Typically, once ...
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APPLICATIONS INFORMATION 900 800 700 600 500 400 300 200 100 0 0 0.5 1 1.5 FREQ/PLLFLTR PIN VOLTAGE (V) Figure 10. Relationship Between Oscillator Frequency and Voltage at the FREQ/PLLFLTR Pin MODE/ PLLIN DIGITAL EXTERNAL PHASE/ OSCILLATOR FREQUENCY DETECTOR ...
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LTC3850/LTC3850-1 APPLICATIONS INFORMATION Although all dissipative elements in the circuit produce losses, four main sources usually account for most of the losses in LTC3850 circuits regulator current losses, 4) Topside MOSFET transition losses. ...
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APPLICATIONS INFORMATION pin. The bandwidth can also be estimated by examining the rise time at the pin. The I external components shown TH in the Typical Application circuit will provide an adequate starting point for most applications. The I series ...
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LTC3850/LTC3850-1 APPLICATIONS INFORMATION f IN Figure 12. Recommended Printed Circuit Layout Diagram BOLD LINES INDICATE HIGH SWITCHING CURRENT. KEEP LINES TO A MINIMUM LENGTH TK/SS1 PU2 V PULL-UP PGOOD I PGOOD TH1 ...
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APPLICATIONS INFORMATION 5. Is the INTV decoupling capacitor connected close CC to the IC, between the INTV and the power ground CC pins? This capacitor carries the MOSFET drivers current peaks. An additional 1µF ceramic capacitor placed im- mediately next ...
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LTC3850/LTC3850-1 APPLICATIONS INFORMATION 4.7µF M1 0.1µF L1 3.3µH 6.19k 1% 1.33k 1% 33pF V OUT1 3.3V 5A 63.4k 1% 1800pF C 20k 4.75k OUT1 100µ L1, L2: COILTRONICS HCP0703 M1, M2: VISHAY SILICONIX Si4816BDY ...
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APPLICATIONS INFORMATION The Coiltronics (Cooper) HCP0703-2R2 (20mΩ DCR at 20°C) and HCP0703-3R3 (30mΩ DCR chosen. At 100°C, the estimated maximum DCR values are 26.4mΩ and 39.6mΩ. The divider ratios are: R 7mΩ SENSE(EQUIV DCR at T ...
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LTC3850/LTC3850-1 TYPICAL APPLICATIONS 4.7µ 2.2µH 8mΩ 15pF V OUT1 3.3V 5A 63.4k 1% 1000pF + 20k C 10k OUT1 1% 1% 220µF L1: TDK RLF 7030T-2R2M5R4 L2: TDK ULF10045T-3R3N6R9 C : SANYO 4TPE220MF OUT1 C : SANYO 6TPE150MI ...
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TYPICAL APPLICATIONS LTC3850/LTC3850-1 31 38501fc ...
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LTC3850/LTC3850-1 TYPICAL APPLICATIONS 32 38501fc ...
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TYPICAL APPLICATIONS 4.7µF M1 0.1µF L1 0.75µH 1.2k 1% 2.94k 1% 47pF V OUT1 1.8V 5A 25.5k 1% 2200pF C 20k 14k OUT1 100µ L1, L2: TOKO FDV0630 0.75µH M1, M2: VISHAY SILICONIX Si4816BDY ...
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LTC3850/LTC3850-1 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 ...
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SIDES) RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED 4.00 ± 0.10 (4 SIDES) PIN 1 TOP MARK (NOTE 6) NOTE: 1. DRAWING ...
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LTC3850/LTC3850-1 PACKAGE DESCRIPTION 4.50 ± 0.05 3.10 ± 0.05 2.50 REF 2.65 ± 0.05 0.25 ±0.05 0.50 BSC RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED PIN 1 TOP MARK (NOTE 6) 5.00 ...
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... Updated Switch Voltage (SW1, SW2) LTC3850I only from 30V to –0.3V to 30V to –5V 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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... LTC3834/ Low I , Synchronous Step-Down Controller Q LTC3834-1 LT3845 Low I , High Voltage Single Output Synchronous Step-Down Q DC/DC Controller PolyPhase is a registered trademark of Linear Technology Corporation Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 l 10k RUN 0.1µF RUN1 FREQ ...