LT1507IS8 Linear Technology, LT1507IS8 Datasheet
LT1507IS8
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LT1507IS8 Summary of contents
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... Temperature rise is kept to a minimum by the high efficiency design. Full cycle-by-cycle short-circuit protec- tion and thermal shutdown are provided. Standard surface mount external parts are used including the inductor and capacitors. , LTC and LT are registered trademarks of Linear Technology Corporation. C2 0.1 F OUTPUT 3.3V L1*** 1 ...
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... NUMBER TOP VIEW LT1507CN8 LT1507CN8-3 LT1507CS8 FB/SENSE 7 LT1507CS8-3.3 GND 6 LT1507IN8 SYNC 5 LT1507IN8-3.3 S8 PACKAGE LT1507IS8 8-LEAD PLASTIC SO LT1507IS8-3 C/W TO 120 PART MARKING = 120 C/W TO 170 C/ W (S) JA 1507 1507I 15073 1507I3 MIN TYP MAX 2.39 2.42 2.45 2.36 2.48 3.25 3.3 3 ...
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ELECTRICAL CHARACTERISTICS 5V 1.5V, boost open, switch open unless otherwise specified PARAMETER CONDITIONS Switch Frequency V – Switch Frequency Line Regulation 4.3V V Frequency Shifting ...
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LT1507 W U TYPICAL PERFORMANCE CHARACTERISTICS Shutdown Pin Bias Current 500 CURRENT REQUIRED TO FORCE SHUTDOWN (FLOWS OUT OF PIN). AFTER SHUTDOWN, 400 CURRENT DROPS TO A FEW A 300 200 8 AT 2.38V STANDBY THRESHOLD (CURRENT FLOWS OUT OF ...
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W U TYPICAL PERFORMANCE CHARACTERISTICS Current Limit Foldback 2.5 FOLDBACK *POSSIBLE CHARACTERISTICS 2.0 UNDESIRED STABLE POINT CURRENT FOR CURRENT SOURCE LOAD SOURCE LOAD 1.5 1.0 MOS LOAD 0.5 RESISTOR LOAD 100 OUTPUT VOLTAGE (%) ...
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LT1507 PIN FUNCTIONS saturation voltage and maximum duty cycle. A typical value for minimum input voltage is 1V above output voltage. Start-up conditions may require more voltage at light loads. See Minimum Input Voltage for details. V ...
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W BLOCK DIAGRAM 2.9V BIAS INTERNAL BIAS REGULATOR V CC SLOPE COMP 500kHz 5 SYNC OSCILLATOR SHUTDOWN COMPARATOR + – 0.4V SHDN 4 3 – LOCKOUT COMPARATOR 2.38V U U APPLICATIONS INFORMATION Note: This application ...
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LT1507 U U APPLICATIONS INFORMATION committing to a final design. The fixed 3.3V LT1507-3.3 has internal divider resistors and the FB pin is renamed SENSE, connected directly to the output. The suggested value for the output divider resistor from FB ...
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U U APPLICATIONS INFORMATION pin (R = R1/R2 4k). The net result is that reductions DIV in frequency and current limit are affected by output voltage divider impedance. Although divider impedance is not critical, caution should be used if resistors ...
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... After making an initial choice, consider secondary things like output voltage ripple, second sourcing, etc. Use the experts in the Linear Technology Applications Depart- ment if you feel uncertain about the final choice. They have experience with a wide range of inductor types and can tell you about the latest developments in low profile, surface mounting, etc ...
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U U APPLICATIONS INFORMATION Table 2. Surface Mount Solid Tantalum Capacitor ESR and Ripple Current E CASE SIZE ESR (MAX ) AVX TPS, Sprague 593D 0.1 to 0.3 AVX TAJ 0.7 to 0.9 D CASE SIZE AVX TPS, Sprague 593D ...
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LT1507 APPLICATIONS INFORMATION Example: with V = 3.3V 5V; OUT 3.3/5 = 0.67 OUT 1.75 – (0.5)(0.66) = 1.42A P Maximum load current would be equal to maximum ...
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U U APPLICATIONS INFORMATION This is safe for short periods of time, but it would be prudent to check with the diode manufacturer if continu- ous operation under these conditions must be tolerated. BOOST PIN CONSIDERATIONS For most applications, the ...
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LT1507 U U APPLICATIONS INFORMATION high speed circulating current path shown in Figure 4 and to make connections to the output capacitor in a manner that minimizes output ripple and noise. For more details, see Applications Information section in the ...
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U U APPLICATIONS INFORMATION is not a problem, but it should be noted that for equal case size , the ripple current rating and ESR of higher voltage capacitors will be somewhat worse. The lower input operating voltages of the ...
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LT1507 U U APPLICATIONS INFORMATION The circuit in Figure 6 will allow operation at light loads with low input voltages. It uses a small PNP to charge the boost capacitor (C2) and an extra diode (D3) to complete the power ...
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U U APPLICATIONS INFORMATION works by prematurely tripping the oscillator before it reaches its normal peak value. For instance, if the oscilla- tor is synchronized at twice its nominal frequency, oscil- lator amplitude will drop by half. A ramp which ...
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LT1507 APPLICATIONS INFORMATION Example: with 3.3V OUT ...
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... MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm) 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 represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights. ...
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... Output Biasing Yields 90% Efficiency Highest Frequency Monolithic Switching Regulator 0.189 – 0.197* (4.801 – 5.004 0.150 – 0.157** (3.810 – 3.988 0.004 – 0.010 (0.101 – 0.254) 0.050 (1.270) BSC SO8 0695 1507f LT/TP 0697 4K • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 1996 ...