mic4744 Micrel Semiconductor, mic4744 Datasheet
mic4744
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mic4744 Summary of contents
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... MIC4744 allows efficiencies over 90%, reduces external components count and eliminates the need for an expensive current sense resistor. The MIC4744 operates from 2.9V to 5.5V input and the output can be adjusted down to 0.6V. The device can operate with a maximum duty cycle of 100% for use in low- dropout conditions. ...
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... Pin Configuration 16-Pin 3mm x 3mm MLF March 2009 Junction Temp. Range Adj. –40° to +125°C Adj. –40° to +125°C ® (YML) 2 Package Lead Finish ® 16-Pin 3mm x 3mm MLF Pb-Free 16-Pin EPAD TSSOP Pb-Free 16-Pin EPAD-TSSOP (YTSE) MIC4744 M9999-030209-C ...
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... SGND Signal (Analog) Ground. Provides return path for control circuitry and internal reference. BIAS Internal circuit bias supply. Must be bypassed with a 0.1µF ceramic capacitor to SGND. Biased through a 10Ω resistor to VIN. GND Connect to ground. 3 MIC4744 M9999-030209-C ...
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... J ® MLF (θ )..........................................................60°C/W JA EPAD TSSOP (θ )............................................35°C/W JA Min Typ 2.9 2.45 2.6 100 = 5.5V 1.4 = 3.6V 1.0 1.6 0.588 0.6 1 2.5 4.3 0.07 0.2 100 155 3.0 3.8 180 0.5 0.9 55 0.1 153 18 MIC4744 IN < +125°C. J Max Units 5 µA 0.612 mΩ 4.4 MHz °C 1 µA °C °C M9999-030209-C ...
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... OUTPUT CURRENT (A) 3.3Vin 2.5Vout Efficiency 4.5Vin 78 5.0Vin 76 5.5Vin 74 1 0.4 0.8 OUTPUT CURRENT (A) Load Regulation 1.010 1.005 1.000 0.995 4.5Vin 5.0Vin 5.5Vin 0.990 1.6 2.0 0 0.4 0.8 OUTPUT CURRENT (A) MIC4744 3.0Vin 3.3Vin 3.6Vin 1.2 1.6 2 4.5Vin 5.0Vin 5.5Vin 1.2 1.6 2 3.0Vin 3.3Vin 3.6Vin 1.2 1.6 2 Vin=3.3V 1.2 1.6 2 M9999-030209-C ...
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... TEMPERATURE (°C) Quiescent Current vs. Supply Voltage 1600 1200 800 400 SUPPLY VOLTAGE (V) Enable Threshold vs. Supply Voltage 1.2 1.0 0.8 0.6 0.4 0.2 0.0 2.9 3.3 3.7 4.1 4.5 4.9 5.3 SUPPLY VOLTAGE (V) 6 MIC4744 Frequency vs. Temperature 4.3 4.2 4.1 4.0 3.9 3.8 3.7 3.6 3.5 3.4 3.3 -40 - 100 120 TEMPERATURE (°C) Rdson vs. Supply Voltage 180 170 160 150 140 130 120 ...
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... Micrel, Inc. Functional Characteristics March 2009 7 MIC4744 M9999-030209-C ...
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... Micrel, Inc. Functional Diagram March 2009 MIC4744 Block Diagram 8 MIC4744 M9999-030209-C ...
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... Please refer to layout recommendations for more details. BIAS The bias (BIAS) provides power to the internal reference and control sections of the MIC4744. A 10Ω resistor from VIN to BIAS and a 0.1µF from BIAS to SGND are required for clean operation. EN1/EN2 The enable pins (EN1 and EN2) provides a logic level control of the outputs 1 and 2 ...
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... Micrel, Inc. Application Information The MIC4744 is a dual 2A PWM non-synchronous buck regulator. By switching an input voltage supply, and filtering the switched voltage through an inductor and capacitor, a regulated DC voltage is obtained. Figure 1 shows a simplified example of a non-synchronous buck converter. Figure 1. Example of Non-synchronous Buck Converter For a non-synchronous buck converter, there are two modes of operation ...
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... In Figure drawn voltage, but to see actual operation (with ringing) refer to the functional characteristics. Discontinuous mode of operation has the advantage over full PWM in that at light loads, the MIC4744 will skip pulses as necessary, reducing gate drive losses, drastically improving light load efficiency. Efficiency Considerations Calculating the efficiency is as simple as measuring power out and dividing it by the power in ...
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... Micrel, Inc. Where D is the duty cycle. Since the MIC4744 uses an internal P-Channel MOSFET, Rdson losses are inversely proportional to supply voltage. Higher supply voltage yields a higher gate to source voltage, reducing the Rdson, reducing the MOSFET conduction losses. A graph showing typical Rdson vs input supply voltage can be found in the typical characteristics section of this datasheet ...
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... ESL. Please refer to layout recommendation for proper layout of the input capacitor. Output Capacitor The MIC4744 is designed for a 4.7µF output capacitor and a 1µH inductor or a 10µF output capacitor and a 0.47µH inductor. X5R or X7R dielectrics are recommended for the output capacitor. Y5V dielectrics lose most of their capacitance over temperature and are therefore not recommended ...
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... The network analyzer will then sweep the source while monitoring A and R for an A/R measurement. The following Bode analysis show the small signal loop stability of the MIC4744, it utilizes type III compensation. This is a dominant low frequency pole, followed by 2 zeros and finally the double pole of the inductor capacitor filter, creating a final 20dB/decade roll off. Bode analysis gives us a few important data points ...
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... March 2009 100000 1000000 By looking at the graph, phase margin can be affected to a greater degree with higher output voltages. 15 Max. Amount of Phase Boost Obtainable Using Cff vs. Output Voltage OUTPUT VOLTAGE (V) M9999-030209-C MIC4744 ...
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... If there does not happen to be any non-shielded bus wire immediately available, the leads from axial resistors will work. By maintaining the shortest possible ground lengths on the oscilloscope probe, true ripple measurements can be obtained. March 2009 16 MIC4744 M9999-030209-C ...
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... CRCW06034K99FKXX CRCW06036K65FKXX CRCW060310K0FKXX CRCW060315K0FKXX R13*, R23* CRCW06032R70FKXX R14, R24 CRCW060349K9FKXX R5 CRCW060310R0FKXX U1 MIC4744YML * Only need for ultra-low noise applications. March 2009 MIC4744YML Schematic for 2A Output Manufacturer Description (1) Murata (2) 10µF Ceramic Capacitor X5R 0603 6.3V TDK (3) AVX (4) Vishay 680pF Ceramic Capacitor NPO 0603 6.3V (4) ...
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... Micrel, Inc. Notes: 1. Murata: www.murata.com. 2. TDK: www.tdk.com. 3. AVX: www.avx.com. 4. Vishay: www.vishay.com. 5. Diode: www.diodes.com. 6. Micrel, Inc: www.micrel.com. March 2009 18 MIC4744 M9999-030209-C ...
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... Micrel, Inc. MIC4744YML Layout Recommendation: 2A Evaluation Board March 2009 Recommended TOP Layout Recommended Bottom Layout 19 MIC4744 M9999-030209-C ...
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... Micrel, Inc. March 2009 Recommended Mid-Layer 1 Layout Recommended Mid-Layer 2 Layout 20 MIC4744 M9999-030209-C ...
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... Micrel, Inc. Package Information March 2009 ® 16-Pin 3mm x 3mm MLF (ML) 21 MIC4744 M9999-030209-C ...
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... Micrel, Inc. March 2009 16-Pin ETSSOP 22 MIC4744 M9999-030209-C ...
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... A Purchaser’s use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully March 2009 indemnify Micrel for any damages resulting from such use or sale. © 2008 Micrel, Incorporated. 23 MIC4744 M9999-030209-C ...