摘要：单位增益运放缓冲而不需要为偏置电阻，电容传感器和其他高阻抗信号源。Maxim > App Notes > AMPLIFIER AND COMPARATOR CIRCUITS Keywords: rail to rail op amp, wide input common mode range, opamps Aug 27, 2001 APPLICATION NOTE 781 AC-Coupled Amplifier Requires No DC Bias Abstract: Unity gain op amp buffers capacitive transducer and other high-impedance signal sources without the need for bias resistors. Capacitive transducers and other high-impedance signal sources usually require AC coupling and a buffer amplifier to condition the signal. Buffers take many forms, but most of them compromise signal quality through external resistors which provide a DC path for the input bias current. Fortunately, recent improvements in op amp technology allow AC-coupled inputs without the need for bias resistors. These new op amps have inpu……