ML4826 Fairchild, ML4826 Datasheet
ML4826
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ML4826 Summary of contents
Page 1
... DC I LIMIT 10 General Description The ML4826 is a high power controller for power factor corrected, switched mode power supplies. PFC allows the use of smaller, lower cost bulk capacitors, reduces power line loading and stress on the switching FETs, and results in a power supply that fully complies with IEC1000-3-2 specifi- cations. The ML4826 includes circuits for the implementa- tion of a leading edge, average current “ ...
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... Positive supply (connected to an internal shunt regulator). CC1 18 V Buffered output for the internal 7.5V reference REF 19 V PFC transconductance voltage error amplifier input FB 20 VEAO PFC transconductance voltage error amplifier output 2 ML4826 20-Pin PDIP (P20) IEAO 1 20 VEAO ...
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... NON INV INV Note 2 ∆ ±0.5V OUT ∆ ±0.5V 1.5V IN OUT V – 3V < V < V – 0.5V CCZ CC CCZ VEAO = 3.75V NON INV INV ML4826 Max. Units 0.3 V CCZ 500 mA 500 mA 1.5 mJ 150 °C 150 °C 260 ° ...
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... ML4826 Electrical Characteristics Unless otherwise specified 25mA Operating Temperature Range (Note 1) A Symbol Parameter Output High Voltage Output Low Voltage Source Current Sink Current Open Loop Gain Power Supply Rejection Ratio OVP Comparator Threshold Voltage Hysteresis PFC I Comparator LIMIT Threshold Voltage ∆ ...
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... Includes all bias currents to other circuits connected to the VFB pin. 3. Gain = K x 5.3V GAINMOD OFFSET REV. 1.0.5 2/14/02 (continued 52.3kΩ RAMP 1 T RAMP1 Conditions 1mA < I(V ) < 20mA REF Line, Load, Temp T = 125˚C, 1000 Hours J ML4826-2, V > 5.7V IEAO V < 1.2V IEAO I = –20mA OUT I = –50mA OUT I = 10mA OUT 20mA OUT I ...
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... ML4826 Typical Performance Characteristics 250 200 150 100 (V) Voltage Error Amplifier (VEA) Transconductance (g Variable Gain Control Transfer Characteristic 20 IEAO VEAO V FB VEA IEA 3.5kΩ 2. GAIN V RMS MODULATOR 4 3.5kΩ I SENSE 3 RAMP 250 ...
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... PFC Section Gain Modulator Figure 1 shows a block diagram of the PFC section of the ML4826. 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 at V set at a level where the active and passive external power components and the ML4826 are within their safe operating voltages, but not so low as to interfere with the boost voltage regulation loop. ...
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... T there are several points which should be noted. Foremost among these is its inherent synchronization to the PFC section of the device, from which it also derives its basic timing (at twice the PFC frequency in the ML4826-2). The PWM is capable of current-mode or voltage mode operation. V ...
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... PWM section at line voltages between 90Vrms and 265Vrms The ML4826 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 dissi- pation while at the same time delivering 10V of gate drive at the PWM OUT and PFC OUT outputs ...
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... IC. Other methods such as a simple series resistor are possible, but can very easily lead to excessive I CC ML4826. Figures 6 and 7 show other possible methods for feeding Leading/Trailing Modulation ...
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... ML4826 RECTIFIED 20V 22kΩ MJE200 Q1 PN2222 18Ω ML4826 1µF RTN Figure 5. V Bias Circuitry 39kΩ 1500µF GATE DRIVE PRODUCT SPECIFICATION V BIAS V CC 1µF ML4826 RTN Figure 6. V BIAS V CC ML4826 RTN Figure 7. REV. 1.0.5 2/14/02 ...
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... Figure 9. Typical Leading Edge Control Scheme. REV. 1.0.5 2/14/02 SW2 SW1 C1 RAMP VEAO – DFF + VSW1 RAMP R Q – CLK Q CLK SW2 SW1 RAMP C1 VEAO DFF CMP VSW1 + R Q – CLK ML4826 TIME TIME VEAO TIME TIME 13 ...
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... ML4826 Figure 10. 48V 300W Power Factor Corrected Power Supply 14 PRODUCT SPECIFICATION REV. 1.0.5 2/14/02 ...
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... PIN 0.060 MIN (1.52 MIN) (4 PLACES) 0.170 MAX (4.32 MAX) 0.125 MIN (3.18 MIN) REV. 1.0.5 2/14/02 inches (millimeters) Package: P20 20-Pin PDIP 1.010 - 1.035 (25.65 - 26.29) 0.240 - 0.260 (6.09 - 6.61) 0.055 - 0.065 0.100 BSC (1.40 - 1.65) (2.54 BSC) 0.015 MIN (0.38 MIN) SEATING PLANE 0.016 - 0.022 (0.40 - 0.56) ML4826 0.295 - 0.325 (7.49 - 8.26) 0.008 - 0.012 0º - 15º (0.20 - 0.31) 15 ...
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... ML4826 Ordering Information Part Number PWM Frequency ML4826CP2 2 x PFC 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; ...