The OPA27GUE4 is an ultra-low noise precision monolithic Operational Amplifier for use with radiation hard equipment. Laser-trimmed thin-film resistors provide excellent long-term voltage offset stability and allow superior voltage offset compared to common zener-zap techniques. An unique bias current cancellation circuit allows bias and offset current specifications to be met over the full -40 to +85°C temperature range. The OPA27 is internally compensated for unity-gain stability.