| 摘要 |
<p>A method for resistance combining double sampling loop negative feedback includes the following steps: a low frequency feedback signal is obtained from a output of an amplifier through a low pass filtering circuit; a high frequency feedback signal is obtained from a high frequency low phase-shifted part of the amplifier through the high pass filtering circuit which order is more than one; a resistance combining circuit is adopted to combine the two way sampling signal to form a signal that both the high and low frequency phase-shifted are lower, and this signal is used for loop negative feedback. A negative feedback amplifier is also disclosed, which includes a voltage amplified circuit, a output buffering circuit, a high speed buffering circuit, a low pass filtering circuit; a high pass filtering circuit which order is more than one, a resistance combining circuit and a feedback network. The method can improve the actual feedback depth of the resistance combining double sampling loop negative feedback amplifier so that the output stage of the amplifier can obtain higher feedback depth just by using lesser band width thus it can reduce the difficulty of realizing deep loop negative feedback.</p> |
