Current vs. Voltage Feedback Amp

　　One question continuously troubles the analog design engineer： ’Which amplifier topology is better for my application， current feedback or voltage feedback？’ In most applications， the differences between current feedback （CFB） and voltage feedback （VFB） are not apparent. Today’s CFB and VFB amplifiers have comparable performance， but there are certain unique advantages associated with each topology. In general， VFB amplifiers offer： • Lower Noise • Better DC Performance • Feedback Freedom Aside from the well-known attribute of CFB amplifiers， gain-bandwidth independence， CFB amplifiers also tend to offer： • Faster Slew Rates • Lower Distortion • Feedback Restrictions With these common attributes known， the design engineer may still ask： ’Why？’ This article will examine the basics of the CFB amplifier in comparison with the VFB amplifier. The following aspects of each topology will be examined：