HiFi Mobile Phone Audio Testing
Mobile phones featuring High Fidelity (HiFi) technology experienced significant growth in 2014 and have driven increases in new product development, with manufacturers replacing conventional codec chips with advanced 192KHz/24-bit DAC and op-amp chips. Through audio, op-amp and other chips, sound quality of mobile phones can compare to 4X CD quality. HiFi technology will continue to be widely applied in mobile phones. As audio performance and quality are enhanced, challenges grow in audio testing. Upgraded function tests are required and can be realized by replacing low-end sound cards with more high-end audio test hardware.
Currently, commercially available sound cards (THD+N: -80 to -90dB, Noise level: 20 to 50µVrms) are unable to satisfy the demands of HiFi measurement, such that manufacturers are required to access suitable 24-bit high precision, low distortion and low noise audio acquisition cards for production line testing with requirements are as follows:
◾Noise level referred to input < 3µVrms
◾THD+N (20Hz – 20KHz) referred to input < -95dB