LTC3605 LINER [Linear Technology], LTC3605 Datasheet
LTC3605
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LTC3605 Summary of contents
Page 1
... Transient Response Shutdown Mode Draws Less Than 15µA Supply n Current LTC3605: 15V Absolute Maximum V n LTC3605A: 22V Absolute Maximum V n The LTC3605A Is Pin Compatible with the LTC3605 n Available in 24-Pin (4mm × 4mm) QFN Package n APPLICATIONS Point of Load Power Supply n Portable Instruments ...
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... LTC3605AEUF#PBF LTC3605AEUF#TRPBF LTC3605AIUF#PBF LTC3605AIUF#TRPBF Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www ...
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... V Falling IN Note 3: Dynamic supply current is higher due to the internal gate charge being delivered at the switching frequency. Note 4: The LTC3605A is tested in a feedback loop that adjusts V achieve a specified error amplifier output voltage (ITH). Note calculated from the ambient temperature T J power dissipation as follows: T Considerations section ...
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... LTC3605A TYPICAL PERFORMANCE CHARACTERISTICS Efficiency vs Load Current 100 V = 12V 1MHz 3.3V OUT V = 2.5V 10 OUT V = 1.8V OUT 0 0.01 0.1 1 LOAD CURRENT (A) 3605A G18 I Current vs Frequency INTVCC 25 MODE = 3.3V NO LOAD 0.5 1 1.5 2 2.5 3 3.5 4 FREQUENCY (MHz) 3605A G03 Load Step (External ITH Compensation) ...
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... V (V) FB DCM Operation CLKOUT 2V/DIV V SW 5V/DIV I L 2A/DIV V = 20V 400ns/DIV 2.5V OUT MODE = OUT L1 = 0.5µH LTC3605A T = 25°C unless otherwise specified. A Efficiency LOAD LOAD (V) IN 3605A G10 ...
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... LTC3605A PIN FUNCTIONS RT (Pin 1): Oscillator Frequency Programming Pin. Con- nect an external resistor (between 200k to 40k) from RT to SGND to program the frequency from 800kHz to 4MHz. Since the synchronization range is ±30% of set frequency, be sure that the set frequency is within this percentage range of the external clock to ensure frequency lock. ...
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... THROUGH RUN OV –3.3µA TO 6.7µA FOLDBACK 3.3µA DISABLED AT START-UP + 0.3V FOLDBACK 0.6 – RUN – – 0.6V 1.2V ITH RUN LTC3605A 3.3V 19 REG C C 17-18 IN2 IN INTV CC 21 BOOST SWITCH LOGIC 11–16 AND D B ANTI- + ...
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... MOSFET is lowered to approximately 40% of the original value to reduce the inductor valley current. Pulling the RUN pin to ground forces the LTC3605A into its shutdown state, turning off both power MOSFETs and most of its internal control circuitry. Bringing the RUN pin above 0 ...
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... RT) and the internal phase- locked-loop allows the LTC3605A to lock onto CLKIN’s phase as well. The CLKOUT signal can be connected to the CLKIN pin of the following LTC3605A stage to line up both the frequency and the phase of the entire system. Tying the PHMODE pin to INTV ...
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... The minimum off-time the smallest amount OFF(MIN) of time that the LTC3605A is capable of turning on the bot- tom power MOSFET, tripping the current comparator and turning the power MOSFET back off. This time is generally about 70ns. The minimum off-time limit imposes a maxi- ...
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... Ferrite designs have very low core losses and are pre- ferred at high switching frequencies, so design goals can concentrate on copper loss and preventing saturation. Ferrite core material saturates “hard”, which means that LTC3605A V OUT ...
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... LTC3605A OPERATION inductance collapses abruptly when the peak design current is exceeded. This results in an abrupt increase in inductor ripple current and consequent output voltage ripple. Do not allow the core to saturate! Table 1. Inductor Selection Table INDUCTANCE DCR MAX CURRENT Vishay IHLP-2525CZ-01 Series 0.33µH 18A 4 ...
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... L1, L2, etc. are the individual losses as a percent- OUT age of input power. Although all dissipative elements in the circuit produce losses, three main sources usually account for most of the losses in LTC3605A circuits and biasing losses, 3) other losses losses are calculated from the DC resistances of ...
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... The goal of the thermal analysis is to determine whether the power dissipated exceeds the maximum junction temperature of the part. The temperature rise is given by: • θ RISE example, consider the case when the LTC3605A is used in applications where V = 12V 1.8V. The equivalent power MOSFET resistance OUT R is: SW ...
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... PGOOD pin, however, with the limited current, no damage will result. Board Layout Considerations When laying out the printed circuit board, the following checklist should be used to ensure proper operation of the LTC3605A (refer to Figure 3). Check the following in your layout the capacitors C connect to the power PV IN ...
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... LTC3605A OPERATION Design Example As a design example, consider using the LTC3605A in an application with the following specifications 10.8V to 13.2V 1.8V OUT I = 500mA 2MHz OUT(MIN) Because efficiency is important at both high and low load current, discontinuous mode operation will be utilized. First select from the characteristic curves the correct R resistor value for 2MHz switching frequency ...
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... PHMODE PV 3 MODE SW LTC3605A TRACK/ ITH RUN PGOOD V PGND 3605A TA03b LTC3605A 20V C 19 IN1 22µF ×2 IN 0.1µ 1.5µH V OUT 15 3.3V 10A 14 100pF 10k C OUT1 13 47µF 2.21k ×2 ...
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... C2 D2 2.2µ CLKIN CLKOUT SGND INTV BOOST PHMODE MODE SW LTC3605A TRACK/ ITH SW RUN PGOOD V PGND IN2 100k C1, C2: AVX 0805ZD225MAT2A D1, D2: CENTRAL SEMI CMDSH-3 C ...
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... UF Package 24-Lead Plastic QFN (4mm × 4mm) (Reference LTC DWG # 05-08-1697 Rev B) 0.70 ±0.05 PACKAGE OUTLINE 0.25 ±0.05 0.50 BSC 0.75 ±0.05 2.45 ±0.10 (4-SIDES) 0.200 REF 0.00 – 0.05 LTC3605A BOTTOM VIEW—EXPOSED PAD PIN 1 NOTCH R = 0.20 TYP 0.115 0.35 × 45° CHAMFER TYP 23 24 0.40 ±0. (UF24) QFN 0105 REV B 0.25 ± ...
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... Negative Converter 0.1µ 2.2µ CLKIN CLKOUT SGND INTV BOOST PHMODE MODE SW LTC3605A TRACK/ 0.1µF RUN PGOOD V PGND 100k 10 3605A TA05b ...