ML4827 Fairchild, ML4827 Datasheet
ML4827
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ML4827 Summary of contents
Page 1
... Current fed gain modulator for improved noise immunity • Overvoltage protection, UVLO, and soft start General Description The ML4827 is a controller for power factor corrected, switched mode power supplies, that includes circuitry Block Diagram 16 VEAO ...
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... Parameter V Shunt Regulator Current CC I Voltage SENSE Voltage on any other Pin I REF I Input Current AC 2 ML4827 16-Pin PDIP (P16) 16-Pin Wide SOIC (S16W) IEAO 1 16 VEAO SENSE REF ...
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... Junction Temperature Storage Temperature Range Lead Temperature (soldering, 10s) Thermal Resistance (θ Plastic DIP Plastic SOIC Operating Conditions Parameter Temperature Range ML4827CP, CS ML4827IP, IS Electrical Characteristics Unless otherwise specified 25mA Symbol Parameter Voltage Error Amplifier Input Voltage Range Transconductance Feedback Reference Voltage ...
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... ML4827 Electrical Characteristics Symbol Parameter Tri-Fault Detect Fault Detect HIGH Time to Fault Detect HIGH Fault Detect LOW PFC I Comparator LIMIT Threshold Voltage ∆(PFC Gain LIMIT TH Modulator Output) Delay to Output DC I Comparator LIMIT Threshold Voltage Input Bias Current Delay to Output ...
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... Conditions V > 4.0V IEAO V < 1.2V IEAO I = –20mA OUT I = –100mA OUT I = 10mA OUT 20mA OUT I = 100mA OUT C = 1000pF L ML4827-1 ML4827 -20mA OUT I = -100mA OUT I = 10mA OUT 20mA OUT I = 100mA OUT C = 1000pF L 25mA < I < 55mA CC Load, Temp V = 11.8V ...
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... ML4827 Typical Performance 250 200 150 100 (V) Voltage Error Amplifier (VEA) Transconductance (g 16 VEAO IEAO V FB VEA IEA 3.5kΩ 15 – + 2.5V + – GAIN V RMS MODULATOR 4 3.5kΩ I SENSE 3 RAMP 250 200 150 100 –500 ) Current Error Amplifier (IEA) Transconductance (g ...
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... PFC Section Gain Modulator Figure 1 shows a block diagram of the PFC section of the ML4827. 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 volt- age, and PFC output voltage. There are three inputs to the gain modulator ...
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... PFC will not restart until the voltage level where the active and passive external power compo- nents and the ML4827 are within their safe operating volt- ages, but not so low as to interfere with the boost voltage of the boost MOS- D regulation loop ...
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... The gain vs. input voltage of the ML4827’s voltage error amplifier has a specially shaped nonlinearity such that under steady-state operating conditions the transconductance of the error amplifi ...
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... ML4827-2. The ML4827-2: Special Considerations for High Duty Cycles The use of the ML4827-1, especially with the type of PWM output stage shown in the Application Circuit of Figure 6, is straightforward due to the limitation of the PWM duty cyle to 50% maximum. In fact, one of the advantages of the “two- transistor single-ended forward converter” ...
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... PFC Stage (the “feedforward” configuration). Figure 3 = RESET shows such a duty cycle clamp. If the ML4827-2’s PWM used in a current-mode design, the PWM stage will require slope compensation. This can be done by any of the standard industry techniques. Note that the ramp to use for this slope compensation is the voltage on RAMP1 ...
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... Solving for the minimum value of C Generating V is less than its FB The ML4827 is a current-fed part. It has an internal shunt voltage regulator, which is designed to regulate the voltage internal to the part at 13.5V. This allows a low power dissipa- tion while at the same time delivering 10V of gate drive at the PWM OUT and PFC OUT outputs ...
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... PRODUCT SPECIFICATION The ML4827 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. Leading/Trailing Modulation Conventional Pulse Width Modulation (PWM) techniques employ trailing edge modulation in which the switch will turn on right after the trailing edge of the system clock ...
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... VEAO REF C15 12 10nF PFC OUT 11 PWM OUT 10 D8 GND 1N5818 D10 LIMIT 1N5818 ML4827-1 C17 R6 220pF R10 41.2kΩ 6.2kΩ PRODUCT SPECIFICATION Q2 IRF830 D5 RGF1J D7 L2 D11 15V 33µH MBR2545CT T2 C24 1µF C21 D6 1800µF ...
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... BSC (1.40 - 1.65) (2.54 BSC) 0.015 MIN (0.38 MIN) SEATING PLANE (0.40 - 0.56) Package: S16N 16-Pin Narrow SOIC 0.386 - 0.396 (9.80 - 10.06) 0.148 - 0.158 0.228 - 0.244 (3.76 - 4.01) (5.79 - 6.20) 0.050 BSC (1.27 BSC) 0.059 - 0.069 (1.49 - 1.75) 0.004 - 0.010 SEATING PLANE (0.10 - 0.26) 0.295 - 0.325 (7.49 - 8.26) 0.008 - 0.012 0° - 15° (0.20 - 0.31) 0° - 8° 0.015 - 0.035 0.006 - 0.010 (0.38 - 0.89) (0.15 - 0.26) ML4827 15 ...
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... Max Duty Cycle ML4827CP-1 ML4827CP-2 ML4827CS-1 ML4827CS-2 ML4827IP-2 ML4827IS-2 DISCLAIMER FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; ...