The OPA380 is an integrator-stabilized operational amplifier that was developed primarily for transimpedance amplifier applications. Its inverting input is that a 90MHz CMOS op amp but its non-inverting input is an integrator non-inverting input, allowing only very low frequency response through this input. In most dual- supply applications, the OPA380 non- inverting input is simply tied to ground. In single- supply applications, it can be used to provide a DC offset. By adding an input resistor, R1, a transimpedance amplifier is transformed into a conventional inverting amplifier. The usual op amp inverting gain equation applies: Av = – (R2/R1) in V/V. The OPA380 is input offset voltage is specified as 4uV typical, 25uV maximum @ 25C, drift is 0.03uV/C typ, 0.1uV/C max. (Circuit is created by Neil P. Albaugh TI- Tucson)
Very Low DC Offset Wideband Amplifier circuit:
Online Simulation of the Very Low DC Offset Wideband Amplifier Circuit
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