As previously mentioned, the OPAx241 series offset voltage is laser-trimmed at 5V. The OPAx251 series is trimmed at ±15V. The initial offset is so low that user adjustment is usually not required. However, the OPA241 and OPA251 (single op-amp versions) provide offset voltage trim connections on pins 1 and 5. Figure 6-1shows how the offset voltage can be adjusted by connecting a potentiometer. Only use this adjustment to null the offset of the op amp, not to adjust system offset or offset produced by the signal source. Nulling offset can degrade the offset drift behavior of the op amp. While predicting the exact change in drift is not possible, the effect is usually small.

Figure 6-1 OPA241 and OPA251 Offset Voltage Trim Circuit