We have a product of audio processor in small batch trial production, but the current PCM1863 used in the product does not pass the CMRR in production test. CMRR is required to be above 40 dB. The typical CMRR value of PCM1863 given in specifications is 56 dB. However, in actual test, the CMRR value of some prototypes is 34-40 dB (trial production of 30 pcs, 6 pcs appears this situation). The test is done by AP tester, please help see what causes this situation? What's the solution?
