US 12,069,452 B2
Audio circuit for interfacing with digital or analog audio signals
Mitsuteru Sakai, Kyoto (JP)
Assigned to ROHM CO., LTD., Kyoto (JP)
Filed by ROHM CO., LTD., Kyoto (JP)
Filed on Apr. 18, 2022, as Appl. No. 17/722,983.
Application 17/722,983 is a continuation of application No. PCT/JP2020/037262, filed on Sep. 30, 2020.
Claims priority of application No. 2019-191304 (JP), filed on Oct. 18, 2019.
Prior Publication US 2022/0240014 A1, Jul. 28, 2022
Int. Cl. H04R 3/12 (2006.01); H03F 3/347 (2006.01); H04R 5/04 (2006.01)
CPC H04R 3/12 (2013.01) [H03F 3/347 (2013.01); H04R 5/04 (2013.01); H03F 2200/03 (2013.01)] 11 Claims
OG exemplary drawing
 
1. An audio circuit comprising:
N input pins, wherein N≥1, via which a digital audio signal or an analog audio signal is to be input;
an audio interface circuit structured such that, when the analog audio signals are input to the N input pins, a bias voltage is applied to each of the N input pins via a bias resistor; and
an internal circuit structured to process the analog audio signal or the digital audio signal that has passed through the audio interface circuit,
wherein the internal circuit comprises:
a D/A converter structured such that, when the digital audio signals are input to the N input pins, the D/A converter is set to an active state so as to convert the digital audio signals into analog signals;
an output selector structured such that, when the digital audio signals are input to the N input pins, the output selector selects an output signal of the D/A converter, and when the analog audio signals are input to the N input pins, the output selector selects the analog audio signals; and
an analog processing circuit structured to process an output of the output selector.