ml4805 Fairchild Semiconductor, ml4805 Datasheet
ml4805
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ml4805 Summary of contents
Page 1
... ML4805 includes circuits for the implementation of a leading edge, average current “boost” type power factor correction and a trailing edge pulse width modulator. The PFC frequency of the ML4805 is automatically set at half that of the PWM frequency generated by the internal oscillator. This technique allows the user to design with smaller output components while maintaining the optimum operating frequency for the PFC ...
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... Connection point for the PWM soft start capacitor 6 V PWM voltage feedback input Connection for oscillator frequency T T setting components 8 RAMP 1 PFC ramp input 2 ML4805 18-Pin PDIP (P18) 18-Pin SOIC (S18) IEAO 1 18 VEAO SENSE REF V RMS 4 ...
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... Storage Temperature Range ...................... –65°C to 150°C Lead Temperature (Soldering, 10 sec) ..................... 260°C Thermal Resistance (θ Plastic DIP ........................................................ 70°C/W 18V Plastic SOIC ................................................... 100°C/W + 0.3V CC OPERATING CONDITIONS 20mA Temperature Range ML4805CX ................................................. 0°C to 70°C ML4805IX ............................................... -40°C to 85°C = 29.4kΩ 15.4kΩ 270pF RAMP1 T CONDITIONS VEAO = 3 ...
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... ML4805 ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER OVP COMPARATOR Threshold Voltage Hysteresis PFC I COMPARATOR LIMIT Threshold Voltage ∆PFC I Threshold - Gain Modulator Output LIMIT Delay to Output DC I COMPARATOR LIMIT Threshold Voltage Input Bias Current Delay to Output V OK COMPARATOR IN Threshold Voltage Hysteresis GAIN MODULATOR Gain (Note 3) ...
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... -20mA OUT I = -100mA OUT I = -10mA OUT 20mA OUT I = 100mA OUT C = 1000pF 12V 14V pin (VEAO - 0.625V ML4805 MIN TYP MAX UNITS 7.4 7.5 7 0.4 % 7.35 7. 0.4 0.8 V 0.7 2.0 V 0.4 0 0.8 ...
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... PFC SECTION Gain Modulator Figure 1 shows a block diagram of the PFC section of the ML4805. The gain modulator is the heart of the PFC this circuit block which controls the response of the current loop to line voltage waveform and frequency, rms line voltage, and PFC output voltage. There are three inputs to the gain modulator ...
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... PFC OUTPUT DRIVER ≅ V /1.6kΩ). The negative SENSE SENSE represents the sum of all currents SENSE of the boost MOSFET(s) and one to monitor D is adequately negative to cancel this increased pin. SENSE pin, as well as being a part of the current ML4805 REF 16 PFC OUT 14 SENSE 7 ...
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... V The OVP trip level should be set at a level where the active and passive external power components and the ML4805 are within their safe operating voltages, but not so low as to interfere with the regular operation of the boost voltage regulation loop. ...
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... No voltage error amplifier is included in the PWM stage No voltage error amplifier is included in the PWM stage of the ML4805, as this function is generally performed on of the ML4805, as this function is generally performed on the output side of the PWM’s isolation boundary. To the output side of the PWM’ ...
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... BIAS The ML4805 should be locally bypassed with a 10nF and a 1µF ceramic capacitor. In most applications, an electrolytic capacitor of between 100µF and 330µF is also required across the part, both for filtering and as part of the start-up bootstrap circuitry. SW2 I2 I3 ...
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... V FB (V) Figure 5. I vs. V VEAO 200 160 120 (V) Figure REV. 1.1 3/9/2001 OTA ML4805 180 (V) Figure OTA 500 (V) Figure Multiplier ...
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... ML4805 PHYSICAL DIMENSIONS 18 PIN 0.045 MIN (1.14 MIN) (4 PLACES) 0.170 MAX (4.32 MAX) 0.125 MIN (3.18 MIN) 0.449 - 0.463 (11.40 - 11.76) 18 PIN 0.024 - 0.034 0.050 BSC (0.61 - 0.86) (1.27 BSC) (4 PLACES) 0.012 - 0.020 0.090 - 0.094 (0.30 - 0.51) (2.28 - 2.39) 12 inches (millimeters) Package: P18 18-Pin PDIP 0.890 - 0.910 (22.60 - 23.12) 0.240 - 0.260 (6.09 - 6.61) 0.050 - 0.065 ...
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... Wide SOIC (S18 critical component in any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system affect its safety or effectiveness. © 2000 Fairchild Semiconductor Corporation ML4805 PACKAGE 13 ...