| 摘要 |
<p>A wide frequency bandwidth amplifier circuit for driving an output load capacitance with large amplitude signals is described in which two separate paths are provided for low frequency and high frequency portions of such signal. The low frequency path is provided by a shunt feedback amplifier connected as an operational amplifier, while the high frequency path is formed by a series feedback amplifier. The gain of the series feedback amplifier, determined by the ratio of its series feedback capacitance divided by the output load capacitance, is made equal to the gain of the operational amplifier, determined by the ratio of its shunt feedback resistance divided by its input coupling resistance. The low frequency cutoff of the high frequency path is above the high frequency cutoff of the low frequency path. Thus, in one embodiment of the amplifier circuit with a frequency response of D.C. to 200 megahertz, the high frequency path has a response of one megahertz to 200 megahertz and the low frequency path has a response of D.C. to 30 megahertz. This embodiment is used as a horizontal sweep amplifier for driving the horizontal deflection plates of a cathode ray oscilloscope with a ramp shaped output signal of 80 volts amplitude and three nanoseconds rise time.</p> |
