MIC3172YM Micrel Inc, MIC3172YM Datasheet
MIC3172YM
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... The MIC2172/3172 is available in an 8-pin plastic DIP or SOIC for –40°C to +85°C operation. ___________________________________________________________________________________________________________ Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 ( April 2006 Features • 1.25A, 65V internal switch rating • 40V input voltage range • ...
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... Figure 2. MIC3172 Flyback Converter Junction Temp. Range Pb-Free MIC2172YN –40°C to +85°C MIC2172YM –40°C to +85°C MIC3172YN –40°C to +85°C MIC3172YM –40°C to +85°C 2 MIC2172/3172 Package 8-pin plastic DIP 8-pin SOIC 8-pin plastic DIP 8-pin SOIC 8-pin SOIC (M) ...
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Micrel Pin Description Pin Number Pin Name 1 S GND 2 COMP (MIC2172) SYNC 4 (MIC3172 VIN 6 P GND 2 7 VSW 8 P GND 1 April 2006 Pin Function Signal Ground: Internal analog ...
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Micrel Absolute Maximum Ratings MIC2172 Input Voltage.................................................................. 40V Switch Voltage ............................................................... 65V Sync Current............................................................... 50mA Feedback Voltage (Transient, 1ms) ............................ ±15V Operating Temperature Range 8-pin PDIP .................................................–40 to +85°C 8-pin SOIC ................................................–40 to +85°C Electrical Characteristics MIC2172 Note 1, 3. ...
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Micrel Typical Characteristics MIC2172 (cont) Parameter Condition Oscillator Section Frequency ( Duty Cycle [δ(max)] Sync Coupling Capacitor V = 3.0V PP Required for Frequency V = 40V PP Lock Input Supply Voltage Section Minimum Operating Voltage 3V ≤ ...
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Micrel Typical Characteristics MIC3172 (cont) Parameter Condition Oscillator Section Frequency ( Duty Cycle [δ(max)] Sync Coupling Capacitor V = 3.0V PP Required for Frequency V = 40V PP Lock Input Supply Voltage Section and Enable Section Minimum Operating ...
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Micrel Typical Characteristics April 2006 7 MIC2172/3172 M9999-041806 (408) 955-1690 ...
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Micrel Typical Characteristics (cont.) April 2006 8 MIC2172/3172 M9999-041806 (408) 955-1690 ...
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Micrel Functional Characteristics April 2006 MIC2172 Block Diagram MIC3172 Block Diagram 9 MIC2172/3172 M9999-041806 (408) 955-1690 ...
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Micrel Functional Description Refer to “Block Diagram MIC2172” and “Block Diagram MIC3172.” Internal Power The MIC2172/3172 operates when ≥ 2.0V for the MIC3172). An internal 2.3V regulator supplies biasing to all internal circuitry including a precision 1.24V ...
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Micrel Application Information Using the MIC3172 Enable Control (New Designs) For new designs requiring enable/shutdown control, connect TTL or CMOS control signal (figure 3). The very low driver current requirement ensures compatibility regardless of the driver or ...
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Micrel locked to an external reference frequency. The slaves lock to the negative (falling edge) of the external reference waveform. Soft Start A diode-coupled capacitor from COMP to circuit ground slows the output voltage rise at turn on (figure 8). ...
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Micrel clamp to the COMP output (figure 9). This feature can be useful in applications requiring either a complete shutdown of Q1’s switching action or a form of current fold-back limiting. This use of the COMP output does not disable ...
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Micrel Figure 10. Single Point Ground A single point ground is strongly recommended for proper operation. The signal ground, compensation network ground, and feedback network connections are sensitive to minor voltage variations. The input and output capacitor grounds and power ...
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Micrel ( ) 2 × 4.75 0.623 ≤ × × × ≤ 26.062µH (use 27µ Equation (3) solves for L1’s maximum current value L1(peak) L1 Where: ...
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Micrel F = safety derating factor (0.8 for most CE commercial and industrial applications maximum input voltage IN(max transformer secondary voltage (V SEC For the practical example 65V max. for the MIC2172/3172 CE F ...
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Micrel Finally, recalculate the transformer turns ratio to insure that it is less than the value earlier found in equation (9 ≤ PRI L SEC Then: − 5 × 1.8 10 ≤ a − 5 × 2.54 10 ...
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Micrel mutual coupling to the feedback winding further reduces primary current eventually turning Q1 off. The primary windings now change state with the feedback winding forcing Q2 on repeating the alternate half cycle exactly as with Q1. This action produces ...
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Micrel April 2006 Figure 14. 12V to 5V Forward Converter Figure 15. LCD Backlight Fluorescent Lamp Supply 19 MIC2172/3172 M9999-041806 (408) 955-1690 ...
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Micrel Package Information MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http:/www.micrel.com The information furnished by Micrel in this data sheet is believed to be accurate and reliable. However, ...