An ideal op-amp has infinite open-loop gain, infinite input impedance, zero output impedance, and infinite bandwidth, but real devices exhibit finite gain, input bias currents, offset voltage, slew-rate limits, and common-mode constraints. Precision design must translate these nonidealities into measurable error budgets.

Common configurations include inverting, noninverting, differential, instrumentation, transimpedance, and integrator circuits. Closed-loop gain is determined primarily by external components, while performance limits are set by bandwidth, slew rate, output swing, and input common-mode range.

Offset voltage introduces constant error, while drift makes that error temperature-dependent. Input bias currents create offsets across source resistances. Finite common-mode rejection ratio and power-supply rejection ratio convert environmental disturbances into output errors. In high-precision systems, chopper stabilization and auto-zero techniques are often used to suppress low-frequency errors.