MIC4720 Micrel Semiconductor, MIC4720 Datasheet
MIC4720
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MIC4720 Summary of contents
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... General Description The Micrel MIC4720 is a high efficiency PWM buck (step- down) regulator that provides output current. The MIC4720 operates at 2.0MHz and has proprietary internal compensation that allows a closed loop bandwidth of over 200KHz. The low on-resistance internal p-channel MOSFET of the ...
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... SW 11 VIN 10 PGND 9 PGOOD ® (ML) 2 Package Lead Finish ® 12-Pin 3x3 MLF Pb-Free 10-Pin ePad Pb-Free MSOP VIN 2 9 VIN SGND 3 8 PGND BIAS 4 7 PGOOD 10-Pin ePad MSOP (MM) MIC4720 M9999-051707 ...
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... No Connect. Not internally connected to die. This pin can be tied to any other pin if desired. EN Enable (Input). Logic level low, will shutdown the device, reducing the current draw to less than 5µA. PGOOD Power Good. Open drain output that is pulled to ground when the output voltage is within +/- 7.5% of the set regulation voltage GND Connect to ground. 3 MIC4720 M9999-051707 ...
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... JC )....................................76°C/W JA )....................................28°C/W JC < +125°C. J Min Typ 2.7 2.45 2.55 100 570 2 0. 100mA 0.07 LOAD 0.2 100 95 1.8 2.0 0.5 0.85 50 0.1 ±7 150 160 25 MIC4720 IN Max Units 5 900 µA 10 µA 1. 200 mΩ 300 2.2 MHz 1 2.3 µA ±10 % 250 Ω °C °C M9999-051707 ...
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... OUTPUT CURRENT (A) MIC4720 1.2V Efficiency OUT OUTPUT CURRENT (A) 5 MIC4720 MIC4720 2.5V Efficiency OUT OUTPUT CURRENT (A) MIC4720 1.5V Efficiency OUT 4. 5. 5.5V IN ...
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... Supply Voltage 120 115 110 105 100 2.7 3.2 3.7 4.2 4.7 5.2 SUPPLY VOLTAGE (V) Enable Threshold vs. Temperature 1.2 1.0 0.8 0.6 0 TEMPERATURE (°C) 6 MIC4720 Feedback Voltage vs. Supply Voltage 1.2 1.0 0.8 0.6 0.4 0 SUPPLY VOLTAGE (V) R DSON vs. Temperature 160 140 120 100 3.3V ...
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... Micrel, Inc. Functional Characteristics Continuous Current Time (200ns/div) Output Ripple Time (200ns/div) May 2007 OUT L = 1µ 4.7µF OUT I = 1.3A OUT 1.0V OUT OUT 7 MIC4720 Load Transient 1.0V OUT Time (100µs/div) M9999-051707 ...
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... Micrel, Inc. Functional Diagram VIN VIN BIAS Enable and EN Control Logic May 2007 Bias, UVLO, Thermal Shutdown SGND MIC4720 Block Diagram 8 P-Channel Current Limit HSD PWM Control Soft EA Start 1.0V 1.0V PGND MIC4720 PGOOD M9999-051707 ...
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... Please refer to layout recommendations. BIAS The bias (BIAS) provides power to the internal reference and control sections of the MIC4720. A 10Ω resistor from VIN to BIAS and a 0.1µF from BIAS to SGND is required for clean operation. EN The enable pin provides a logic level control of the output. In the off state, supply current of the device is greatly reduced (typically < ...
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... Micrel, Inc. Application Information The MIC4720 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 MIC4720 will skip pulses as nessasary, 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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... For discontinuous losses due to the operation, the transition losses only occur during the “off” transition since the “on” transitions there is no current flow through the inductor. 12 Figure 6. Switching Transition Losses ) and the current through the switch (I S-D MIC4720 ) are S-D M9999-051707 ...
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... Inductor Selection The MIC4720 is designed for use with a 1µH inductor. Proper selection should ensure the inductor can handle the maximum average and peak currents required by the load. Maximum current ratings of the inductor are generally given in two methods ...
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... You could be overdriving the feedback causing a large signal response. 14 Network Analyzer “R” Input +8V MIC922BC5 Figure 8. Op Amp Injection MIC4720 Network Analyzer “A” Input R1 1k Output Network Analyzer Source M9999-051707 ...
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... Micrel, Inc. The following Bode analysis show the small signal loop stability of the MIC4720, 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. ...
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... As you can see the typical phase margin, using the same resistor values as before without a feedforward capacitor results in 33.6 degrees of phase margin. Our prior measurement with a feedforward capacitor yielded a phase margin of 47 degrees. The feedforward capacitor has given us a phase boost of 13.4 degrees (47 degrees- 33.6 Degrees = 13.4 Degrees). 16 MIC4720 M9999-051707 ...
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... I × 707 R LOAD Output Impedance vs. Frequency 1 V =1.8V OUT L=1µH C =4.7µF + 0.1µ OUT 0.1 3.3VIN 0. 0.001 10 100 1k 10k 100k 1M FREQUENCY (Hz) A/sec = f π 2 ∆ = ∆ × OUT OUT OUT ↓ DCR X DSON L ↓ TOTAL ↑ GAIN MIC4720 X COUT M9999-051707 ...
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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. shortest possible ground lengths on the oscilloscope probe, true ripple measurements can be obtained. May 2007 By maintaining the 18 MIC4720 M9999-051707 ...
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... Micrel, Inc. Recommended Layout: 2A Evaluation Board May 2007 Recommended Top Layout Recommended Bottom Layout 19 MIC4720 M9999-051707 ...
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... Micrel, Inc. MIC4720 Schematic and BOM for 2A Output Item Part Number C1a,C1b C2012JB0J106K GRM219R60J106KE19 08056D106MAT C2 0402ZD104MAT C3 C2012JB0J475K GRM188R60J475KE19 06036D475MAT C4 VJ0402A820KXAA D1 SSA33L L1 RLF7030-1R0N6R4 744 778 9001 IHLP2525AH-01 1 R1,R4 CRCW04021002F R2 CRCW04026651F CRCW04021242F CRCW04022002F CRCW04024022F R3 CRCW040210R0F U1 MIC4720BML Notes: 1. TDK: www.tdk.com 2. Murata: www.murata.com 3. AVX: www.avx.com 4. Vishay: www ...
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... 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 May 2007 12-Pin 3mm x 3mm MLF indemnify Micrel for any damages resulting from such use or sale. © 2006 Micrel, Incorporated. 21 ® (ML) MIC4720 nt M9999-051707 ...