[解] 本电路中的基本放大电路是由运放[tex=0.786x1.0]Yn3GgEZev6SOu2r4v1WnCw==[/tex]和[tex=1.0x1.214]1BSfXLm3ln/dNzdj6Isy4Q==[/tex]与[tex=1.0x1.214]ScYSgOIQ6JVTkJpOljRNMg==[/tex]组成的乙类互补推挽放大电路构成。[tex=2.786x1.0]APAqSV1Dq7TIfQHGNNswWQ==[/tex]电阻是反馈元件。可以判定,本电路是交直流电压并联负反馈电路。反馈系数为[tex=3.214x2.857]zEz7nvAGEfEbi1ifnStYYVlp04CCzy6ezTMLMiYB8VMfmIEYn1luBVjrVGdyQbhDDS8SEU+MUbXLbi3R0YptUg==[/tex][tex=8.714x2.857]WeTj84JhjQG/q0DvaPMVLvD8VvQjsYRe2yB7y+Nf5MJugjpo5qhHTXnxpj9Eef7J9C8z4+TLW4h0hn93nbLtuJQCA7bQ9TjbwPtoUbgkmNU=[/tex]在深反馈条件下，互阻增益为[tex=10.429x2.857]fLBi9lHB+gQNoTY9O4A1FoYVAEwTKcZGYHa5w2Kc1oIUYtfUw3/22v2tbkso0QC6Tofm5rQYJ9/jnKEsxHru6qqL6kk138BgEW3410gCLmU=[/tex][br][/br]闭环电压放大倍数为[tex=8.0x2.929]47OY9EaTtpfq3VgpHmn4e4p0MqavAQnadzD6nZonFQNQ0STpB6+WiPiak5EcuyFJ6roDvYugMun6kWCYMaikcXjfA87UePLVdcQ2jKPS8m/pBXb33zWancvlazjLA3eV[/tex][tex=9.0x2.643]3jz1Ms/WfUQTdZ9rWjylv9UFX/dcrFdHqRyFifSlZOb/duFrUpmPNO16CPIq2KoY[/tex]闭环输入电阻[tex=7.143x2.214]8pVLDE51V1sLk42MYxzDxc0w+D41xLDC1CH43NH7wh94l3Lxxcszqao6vNUzb26G[/tex][tex=5.214x1.214]WYSGuRDoUIdFOmWfIWjmAEF4g7OY4v8sOoUxQtAnJy0=[/tex]闭环输出电阻近似为零,即[tex=3.286x1.286]on1UVypfFUKqiZKQ6qHU7pz68r3nBOk3javprVdp9iA=[/tex]。