開關電源外文翻譯-其他專業(yè)(文件)
【正文】 highlights the versatility and limitations of the control circuitand gives a thorough understanding of their interrelationship. Applying the control circuit toseveral basic applications demonstrates the circuits’usefulness and outlines some stillunresolved problems. The control signals are derived from two sources:the deadtime(offtime) control circuitand the error amplifier circuit. The deadtimecontrol input is pared directly by thedeadtimecontrol parator has a fixed 100mV the controlinput biased to ground ,the output is inhibited during the portion of time the sawtoothwaveform is below 110mV. This provides a preset dead time of approximately 3%, which isthe minimum dead time that can be programmed. The PWM parator pares the controlsignal created by the error amplifiers. One function of the error amplifer is to monitor theoutput voltage and provide sufficient gain so that millivolts of error at its input will result in acontrol signal of sufficient amplitude to provide 100% modulation control. The erroramplifiers can also be used to monitor the output current and provide current limiting to theload. The TL494 incorporates all the functions required in the construction of a pulsewidthmodulation(PWM) control circuit on a single chip. Design primarily for powersupply control ,this device offers the flexibility to tailor the powersupply control circuitry to a specific application. It contains two error amplifiers , an onchip adjustable oscillator , a deadtime control(DTC) parator , a pulsesteering control flipflop , a ,5%precision regulator , and outputcont
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鄂ICP備17016276號-1