APA2121

APA2120/1 is a monolithic integrated circuit, which provides precise DC volume control, and a stereo bridged audio power amplifiers capable of producing 2.7W(2.0W) into 3 with less than 10% (1.0%) THD+N. The attenuator range of the volume control in APA2120/1 is from 20dB (DC_Vol=0V) to -80dB (DC_Vol=3.54V) with 32 steps. The advantage of internal gain setting can be less components and PCB area. Both of the depop circuitry and the thermal shutdown protection circuitry are integrated in APA2120/1, that reduce pops and clicks noise during power up or shutdown mode operation. It also improves the power off pop noise and protects the chip from being destroyed by over temperature and short current failure. To simplify the audio system design, APA2120/1 combines a stereo bridge-tied loads (BTL) mode for speaker drive and a stereo single-end (SE) mode for headphone drive into a single chip, where both modes are easily switched by the SE/BTL input control pin signal. Besides, the multiple input selection is used for portable audio system.