Recently purchased 2 TI PCM56P devices from farnell. The devices are not behaving the same as the original BB (Burr Brown) device. For a fixed input the TI device is producing 2.247V (loaded 5.3k and unloaded O/C) the original BB device produces 2.375V (loaded 5.3k and unloaded o/c) The voltage rails are -5.03V and +4.997V.
The output from the TI PCM56P is linear with no discontinuities just seems to be operating with slightly lower gain. There is no circuitry connected to pins 14 or 15 ie they or o/c.
In the same circuit the output of BB original chips provides 2.373V and the two TI chips provide 2.247V
Is there anything that could explain this.