LTC1435 Linear Technology, LTC1435 Datasheet
LTC1435
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LTC1435 Summary of contents
Page 1
... Burst Mode is a trademark of Linear Technology Corporation 4.5V TO 28V Si4412DY LTC1435 10 H CMDSH-3 C INTV B CC 0.1 F BOOST + 4 Si4412DY PGND – + SENSE 1000pF Figure 1. High Efficiency Step-Down Converter LTC1435 Switching Regulator 35V R SENSE 2 0.033 V OUT 2.9V/3. 32.4k + OUT 100 F 10V 22.1k MBRS140T3 1435 F01 1 ...
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... Peak Driver Output Current < (TG, BG) ............. 2A INTV Output Current ........................................ 50mA CC Operating Ambient Temperature Range LTC1435C............................................... LTC1435I............................................ – Junction Temperature (Note 1)............................. 125 C Storage Temperature Range ................. – 150 C Lead Temperature (Soldering, 10 sec).................. 300 C ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER ...
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... 15V RUN/SS Note 2: The LTC1435 is tested in a feedback loop which servos V to the balance point for the error amplifier (V Note 3: Dynamic supply current is higher due to the gate charge being delivered at the switching frequency. See Applications Information. and power ...
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... LTC1435 W U TYPICAL PERFORMANCE CHARACTERISTICS Input Supply and Shutdown Current vs Input Voltage 2.5 2 OUT 1.5 EXTV = V CC OUT V = 3.3V 1.0 OUT EXTV = OPEN CC 0.5 SHUTDOWN INPUT VOLTAGE (V) 1435 G07 Normalized Oscillator Frequency vs Temperature –5 –10 – 40 – ...
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... TG (Pin 16): High Current Gate Drive for Top N-Channel + MOSFET. This is the output of a floating driver with a and SENSE pins in voltage swing equal to INTV switch node voltage SW. power when- CC LTC1435 Soft Start: Load Current vs Time 1435 G17 is higher than 4.7V. See EXTV 5V. OUT OUT ...
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... LTC1435 U U FUNCTIONAL DIAGRA + OV – 1.28V V OSENSE V FB – 1.19V 180k m + – SHUTDOWN RUN 30k SOFT START RUN/ FOLDBACK CURRENT LIMITING OPTION OSC SFB OSC 1 A – + 1.19V SHUTDOWN OSC ...
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... MOSFET and keeping it off until the fault is removed. Low Current Operation The LTC1435 is capable of Burst Mode operation in which the external MOSFETs operate intermittently based on load demand. The transition to low current operation begins when comparator I2 detects current reversal and turns off the bottom MOSFET ...
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... LTC1435 U U APPLICATIONS INFORMATION The basic LTC1435 application circuit is shown in Figure 1, High Efficiency Step-Down Converter. External compo- nent selection is driven by the load requirement and begins with the selection of R SENSE known, C and L can be chosen. Next, the power OSC MOSFETs and D1 are selected. Finally, C selected ...
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... Selection criteria for the power MOSFETs include the “ON” resistance R input voltage and maximum output current. When the LTC1435 is operating in continuous mode the duty cycles for the top and bottom MOSFETs are given by: Main Switch Duty Cycle = Synchronous Switch Duty Cycle = ...
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... LTC1435 U U APPLICATIONS INFORMATION where is the temperature dependency constant inversely related to the gate drive current. 2 Both MOSFETs have I R losses while the topside N-channel equation includes an additional term for tran- sition losses, which are highest at high input voltages. For V < ...
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... MOSFET gate drivers. High input voltage applications, in which large MOSFETs are being driven at high frequencies, may cause the maximum junction temperature rating for the LTC1435 to be exceeded. The IC supply current is dominated by the gate charge supply current when not using an output derived EXTV source ...
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... OUT R 1 The external resistor divider is connected to the output as shown in Figure 5 allowing remote voltage sensing. Run/ Soft Start Function The RUN/SS pin is a dual purpose pin which provides the soft start function and a means to shut down the LTC1435 0.22 F BAT85 ...
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... DS(ON) where L1, L2, etc. are the individual losses as a percentage of input power. Although all dissipative elements in the circuit produce losses, four main sources usually account for most of the pin as shown in the losses in LTC1435 circuits. LTC1435 V = 0V) the OUT 2 current The V IN electrical characteristics which excludes MOSFET driver and control currents ...
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... Although the LT1435 has a maximum input can OUT voltage of 36V, most applications will be limited to 30V by the MOSFET BV 12V . No regulator OUT Figure 7. Automotive Application Protection ). Thus capacitor would require a 250 s . DSS 50A I PK RATING V IN LTC1435 TRANSIENT VOLTAGE SUPPRESSOR GENERAL INSTRUMENT 1.5KA24A 1435 F07 ...
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... LTC1435. These items are also illustrated graphically in the layout diagram of Figure 8. Check the following in your layout: 1. Are the signal and power grounds segregated? The LTC1435 signal ground pin must return to the (–) plate of C OUT the bottom N-channel MOSFET, anode of the Schottky diode, and (– ...
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... LTC1435 INTV 4 OSENSE 10 – PGND 9 + EXTV OUT + R2 Figure 8. LTC1435 Layout Diagram Dual Output 5V and Synchronous 12V Application V IN 5.4V TO 28V Si4412DY 15 BOOST 0.1 F CMDSH-3 12 INTV Si4412DY 10 PGND 9 EXTV CC ...
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... H 0.025 V OUT 3.3V/4.5A R1 35. OUT + 100 F MBRS140T3 10V 100pF R2 2 20k 1% SGND (PIN 5) LTC1435 • TA01 35V 2 MBRS1100T3 24V SEC 10 H 3.3 F 1:2.2 25V V OUT 5V/3.5A R SENSE R1 0.033 35. MBRS140T3 + OUT 100 F 10V R2 2 20k 1% SGND LTC1435 • TA02 V OUT2 12V 17 ...
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... CAPACITOR MANUFACTURER FOR RECOMMENDED GND I ESR RATING FOR CONTINUOUS 4A OPERATION PROG R PROG 18 C4 0.1 F C11 0.1 F 56pF OSC 2 15 RUN/SS BOOST LTC1435 4 13 0.33 F SFB SGND INTV OSENSE 7 10 – SENSE PGND SENSE EXTV ...
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... LTC1435 0.239 – 0.249* (6.07 – 7.33 0.301 – 0.311 (7.65 – 7.90 G16 SSOP 0795 0.386 – 0.394* (9.804 – ...
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... L1 R SENSE 10 H 0.033 R1 35.7k 100pF 1% MBRS140T3 + R2 24.9k 1% SGND LTC1435 • TA03 COMMENTS 20V IN Synchronous, V 20V IN Synchronous, V 40V, For Logic Threshold FETs IN High Frequency, Small Inductor, High Efficiency Switchers, 1.5A Switch High Efficiency 5V to 3.3V Conversion 15A Full-Featured Single Controller Full-Featured Dual Controllers 1 ...