MAX5020 Maxim Integrated Products, MAX5020 Datasheet
MAX5020
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MAX5020 Summary of contents
Page 1
... The MAX5019 allows 85% operating duty cycle and can be used to implement flyback converters whereas the MAX5020 limits the operating duty cycle to less than 50% and can be used in single-ended for- ward converters. A high-voltage startup circuit allows these devices to draw power directly from the 18V to 110V input supply during startup. The switching fre- quency is internally trimmed to 275kHz ± ...
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Current-Mode PWM Controllers with Integrated Startup Circuit ABSOLUTE MAXIMUM RATINGS V+ to GND ……………………………………...……-0.3V to +120V V to GND.………………………………….……….-0.3V to +40V GND.………………….……………………-0.3V to +12.5V CC FB, NDRV, SS_SHDN GND .……-0. and V ...
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... V+ = 48V, 0.1µF capacitor connected from SS_SHDN to GND, NDRV CC CS CONDITIONS SCOMP GND ILIM 0 ≤ V ≤ 2V GND CS 50mV overdrive on CS GND FB = GND, only PWM comparator is blanked FB = GND MAX5019 GND MAX5020 GND SSO SS_SHDN _SHDN No external load V falling SS_SHDN V rising SS_SHDN Typical Operating Characteristics = +25° ...
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... Current-Mode PWM Controllers with Integrated Startup Circuit (V+ = 48V 13V GND, NRDV is open circuit MAX5020 MAXIMUM DUTY CYCLE vs. TEMPERATURE 48.0 47 GND 47.6 47.4 47.2 47.0 46.8 -40 - TEMPERATURE (°C) V+ INPUT CURRENT vs. TEMPERATURE (AFTER STARTUP) 13.80 13. 110V 13V GND DD 13.70 13.65 13.60 13.55 13.50 -40 - TEMPERATURE (°C) NDRV RESISTANCE vs ...
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... V+ VOLTAGE (V) V VOLTAGE vs 10 110V, V 10.2 V 10.0 9.8 9.6 9.4 9.2 9.0 0 5.0 10.0 V CURRENT (mA) CC _______________________________________________________________________________________ Typical Operating Characteristics (continued) = +25°C, unless otherwise noted.) A MAX5020 MAXIMUM DUTY CYCLE vs. V 48.0 47 GND FB 47.7 47.6 47.5 DEVICE POWERED FROM V 47.4 DD 47.3 47.2 DEVICE POWERED FROM V+ 47.1 47 (V) DD ...
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... The internal oscillator is set to 275kHz and trimmed to ±10%. This permits the use of small mag- netic components to minimize board space. Both the MAX5019 and MAX5020 can be used in power sup- plies providing multiple output voltages. A functional diagram of the IC is shown in Figure 1. Typical applica- tions circuits for forward and flyback topologies are shown in Figure 2 and Figure 3, respectively ...
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Current-Mode PWM Controllers with Integrated HIGH- VOLTAGE GND REGULATOR EN MAX5019 ONLY SLOPE COMPENSATION 26mV/µs 26mV/µs 1MΩ 50kΩ FB ERROR AMP SS_SHDN 2.4V 0.25V Figure 1. Functional Diagram _______________________________________________________________________________________ IN BIAS WINDING REGULATOR EN OUT OUT ...
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... This eliminates the need for a tertiary winding. Undervoltage Lockout (UVLO), Soft-Start, The soft-start feature of the MAX5019/MAX5020 allows the load voltage to ramp controlled manner, thus eliminating output voltage overshoot. While the part is in UVLO, the capacitor connected to the SS_SHDN pin is discharged ...
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... SS_SHDN C SS GND MAX5019 FB MAX5020 NDRV 100Ω CC SS_SHDN GND C SS SS_SHDN The current-sense (CS) comparator and its associated logic limit the peak current through the MOSFET. Current is sensed voltage across a sense resistor between the source of the MOSFET and GND ...
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... The propagation delay from the time the switch current reaches the trip level to the driver turn-off time is 180ns. Internal Error Amplifier The MAX5019/MAX5020 include an internal error ampli- fier that can be used to regulate the output voltage in the case of a nonisolated power supply (see Figure 2). ...
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... Figures 2 and 3. 3) The turns ratio of the transformer is calculated based on the minimum input voltage and the lower limit of the maximum duty cycle for the MAX5020 (44%). To enable the use of MOSFETs with drain-source breakdown voltages of less than 200V use the MAX5020 with the 50% maximum duty cycle. ...
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Current-Mode PWM Controllers with Integrated Startup Circuit 14 ≥ × DSMAX 14 Choose MOSFETs with appropriate avalanche power ratings. 5) Choose the tertiary winding turns ratio (N that the minimum input ...
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... Current-Mode PWM Controllers with Integrated Table 1. Component Manufacturers Power FETS Current-Sense Resistors Diodes Capacitors Magnetics Selector Guide MAXIMUM PART DUTY CYCLE MAX5019CSA 85% MAX5019ESA 85% MAX5020CSA 50% MAX5020ESA 50% ______________________________________________________________________________________ International Rectifier Fairchild Vishay-Siliconix Dale-Vishay IRC On Semi General Semiconductor Central Semiconductor Sanyo Taiyo Yuden AVX Coiltronics Coilcraft Pulse Engineering ...
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... Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 14 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products ...