MIC2145 Micrel Semiconductor, MIC2145 Datasheet
MIC2145
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MIC2145 Summary of contents
Page 1
... Its typical 450kHz operation allows small sur- face mount external components to be used. The MIC2145 has a low quiescent current of 200 A, and a typical shutdown current of 0.5 A. The MIC2145 is capable of high efficiencies in a small board area. The MIC2145 features a low-on resistance internal switch that allows it to provide over 2 ...
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... MIC2145 8 SGND VDD 5 SW Pin Function EN Enable (Input): Logic high ( 1.5V) enables regulator. Logic low ( 0.7V) shuts down regulator. Do not float. SS Soft Start Capacitor (External Component): Connect external capacitor to ground to control the rise time of the output voltage. ...
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... ....................... – +125 125 C. J Min Typ Max 2.4 16 0.5 5 200 300 1.058 1.08 1.102 1.048 1.112 18 40 0.8 0.9 500 500 750 250 400 1000 1.1 0.7 1.5 1.1 –1 0.01 1 –1 0.01 1 –8 –12 –16 MIC2145 Micrel Units ...
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... DD Quiescent Current vs 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0. (V) DD Off Time vs. Temperature 1.5 1.4 1.3 1.2 1.1 1.0 0.9 0.8 0.7 0.6 0.5 -40 - 100 TEMPERATURE ( C) MIC2145 Efficiency-Bootstrapped Configuration 100 3. 10V = OUT OUTPUT CURRENT (A) Switch On-Resistance vs 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 (V) ...
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... SET 0.8 0.7 0.6 0 10k IN 0.3 SET V = 10V 0.2 OUT 0.1 0 -40 - 100 TEMPERATURE ( C) 5 Micrel Peak Current Limit vs. RSET 2000 VIN = 1800 15V 1600 12V 1400 10V 1200 8.0V 1000 5.0V 800 4.2V 3.6V 600 3. 3.0V VOUT/VIN > 1.25 2.4V 400 100 1000 10000 100000 RSET( ) MIC2145 ...
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... MIC2145 Functional Diagram RSET 3 R SET Thermal Shutdown EN On(/Off) 1 MIC2145 VDD 6 Current Limit Comparator Soft One Shot Start 800nS Feedback Comparator / Figure 1. Block Diagram OUT OUT R2 POWER SGND MOSFET ...
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... There is a minimum resistor value for R value selections, see the Current Limit vs. R Soft Start The MIC2145 has a built in soft start that controls the rise time of the output voltage and the peak current limit threshold during start up. experiences a typical (500mA/div) ...
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... V SW (5V/div) Time 20 s Figure 4. Without Feed-Forward Capacitor MIC2145 A value recommended for R1 to minimize the quiescent current when the part is off. Then, R2 can be solved using the above equation. A feed-forward capacitor, C ranging from 5pF to 100pF can be used in parallel with R1 to reduce the peak-to-peak output voltage ripple, which is shown in Figures 4 and 5 ...
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... PGND SW SGND VDD MIC2145 EN RSET R1 100k 10k 0. 274k Figure 7. Bootstrap Configuration 9 pin is connected to the input voltage DD V OUT 5V/250mA F/6. Murata 100pF GRM42-6 X5R 106K 6 OUT 5V/350mA C4 10 F/6.3V C3 Murata 100pF GRM42-6 X5R 106K 6.3 Micrel MIC2145 ...
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... MIC2145 Inductor The MIC2145 has a programmable peak current to allow the usage of small surface mount inductors 4.7 H inductor is recommended for most portable applications such as powering white LEDs and biasing LCD panels. The ...
Page 11
... Output Capacitor Low ESR capacitors should be used at the output of the MIC2145 to minimize the switching output ripple voltage. Selection of the capacitor value will depend upon the peak inductor current, inductor size, and the load. MuRata offers the GRM43-2 series with 25V, with a X5R temperature coefficient in a 1812 surface-mount package ...
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... GRM42-6 X5R 106K 6.3 JP1 R1 R2 100k 10k Figure 8. White LED Driver Application (Drives LEDs in Parallel) MIC2145 L1 4.7 H Murata LQH3C4R7M24 D1 On Semiconductor MBR0530T1 VDD SW EN PGND 100pF MIC2145 FB RSET R3 274k SS SGND C2 0. ...
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... Output Efficiency 3. 100 OUTPUT CURRENT (mA OUT 10. F/16V 1M 100pF Murata GRM42-2 X5R 106K 16 R3 121k 1000 Micrel MIC2145 ...
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... MIC2145 V IN 3.0V-5. F/6.3V Murata GRM42-6 X5R 106K 6.3 JP1 R1 R2 100k 10k MIC2145 Sumida CR32-100 D1 On Semiconductor MBR0530T1 PGND SW EN VDD 100pF MIC2145 FB RSET R3 78.7k SS SGND C2 0. ...
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... FAX Micrel for any damages resulting from such use or sale. © 2003 Micrel, Incorporated. 15 DIMENSIONS: INCH (MM) 0.007 (0.18) 0.005 (0.13) 0.012 (0.03) R 0.039 (0.99) 0.035 (0.89) 0.021 (0.53) +0.15 1.60 —0.15 +0.15 0.80 —0.15 PIN 1 ID +0.07 —0.05 1 +0.15 1.15 2 —0.15 +0.15 3 2.30 —0.15 +0.15 0.40 —0.05 BOTTOM +0.07 0.23 —0.05 +0.04 0.01 —0.01 http://www.micrel.com WEB Micrel MIC2145 ...