The dual-channel INA1650 and single-channel INA1651 (INA165x) SoundPlus™ audio line receivers achieve an extremely-high common-mode rejection ratio (CMRR) of 91 dB while maintaining an ultra-low THD+N of –120 dB at 1 kHz for 22-dBu signal levels. Precision matching of on-chip resistors give the INA165x devices excellent CMRR performance. These resistors have matching that is far superior compared to external components, and are immune to mismatches introduced by printed circuit board (PCB) layout. Unlike other line receiver products, the INA165x CMRR is characterized over temperature and tested in production to deliver consistent performance in a wide variety of applications. The INA165x devices operate over a very-widesupply range of ±2.25 V to ±18 V, on 10.5 mA of supply current. In addition to the line-receiver channels, a buffered mid-supply reference output is included, making the INA165x configurable for dualor single-supply applications. The mid-supply output can be used as a bias voltage for other analog circuitry in the signal chain. These devices are specified from –40°C to +125°C.
“The primary role of this project is to convert a differential input audio signal into a single-ended output signal while rejecting noise that is common to both inputs (common-mode noise). The circuit presented here is a differential amplifier intended to …