SBOS487B June 2009 – March 2020 PGA280
The output stage of PGA280 is designed for highest precision. The fully-differential output avoids grounding errors and noise, and delivers twice the signal amplitude compared to single-ended signals. However, if desired, the output can be taken single-ended from one of the output pins referred to the voltage at the VOCM pin. The output stage errors now relate to half the signal amplitude and half the signal gain. The unused output is unconnected, but not disconnected from error detection. The usable voltage range for the VOCM input is specified in the and must be observed: the output swing (of both outputs) should not saturate to the supply. Separate specifications for offset voltage and drift indicate higher offset voltage at lower gains, because some error sources are not cancelled in the output stage connected in single-ended mode. Note that the gain is one-half of the gain set in reference to the gain table (see Table 2).