AD1987 is an audio decoder chip released by Analog Devices, supporting 7.1 surround sound output, supporting 8kHz, 11.025 kHz, 16 kHz, 22.05 kHz, 32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz and 192 kHz sampling rates, supporting 16-, 20-, and 24-bit PCM resolution, and supporting independent headphone outputs.