In the iPhone Ightning headphones, integrated with DA decoding and ear amplifier chip, that is, we often say C100 chip.
Its random lightning interface EarPods headphones, lightning cable, are integrated with a small DAC decoding chip and drive headphones chip, we call it \"digital tail\".
The DAC uses ESS ES9218P. PCM supports up to 32bit\/384kHz, DSD supports up to Native DSD256. The decoding chip works really well.