DAC Playback with 48ksps Sample Rate through Class-D Headphone Amplifiers
#----------- Power-up
#----------- Initialize to page 0
w 30 00 00
#----------- Initialize the device through software reset
w 30 01 01
#----------- Power up the NDAC divider with value 1
w 30 0b 81
#----------- Power up the MDAC divider with value 4
#----------- For class-D mode, MDAC = I*4
w 30 0c 84
#----------- Program the OSR of DAC to 128
w 30 0d 00
w 30 0e 80
#----------- Set the DAC Mode to PRB_P1v
w 30 3c 01
#----------- Select page 1
w 30 00 01
#----------- Disable internal crude AVdd in presence of external AVdd supply
#----------- or before powering up internal AVdd LDO
w 30 01 08
#----------- Enable master analog power control
w 30 02 00
#----------- Set the REF charging time to 40ms
w 30 7b 01
#----------- Set the input common mode to 0.9V and output common mode for headphone
#----------- to input common mode
w 30 0a 00
#----------- Enable class-D mode for HPL output
w 30 03 c0
#----------- Enable class-D mode for HPR output
w 30 04 c0
#----------- Route left DAC to HPL
w 30 0c 08
#----------- Route right DAC to HPR
w 30 0d 08
#----------- Unmute HPL driver
w 30 10 00
#----------- Unmute HPR driver
w 30 11 00
#----------- HP soft stepping settings for optimal pop performance at power up
#----------- Rpop used is 6k with N = 6 & soft step = 20usec.
w 30 14 29
#----------- Power up HPL and HPR drivers
w 30 09 30
#----------- Wait for 2.5 sec for soft stepping to take effect
#----------- Else read Page 1, Register 63d, D(7:6). When = “11” soft-stepping is complete
#----------- Switch to page 0
w 30 00 00
#----------- Power up the left and right DAC channels and route the left channel I2S data
#----------- to left channel DAC and right channel I2S data to right channel DAC
w 30 3f d4
#----------- Unmute the DAC digital volume control
w 30 40 00
#----------- Breakpoint
b
#----------- Power-down
#----------- Select page 1
w 30 00 01
#----------- Power down HPL and HPR drivers
w 30 09 00
#----------- Select page 0
w 30 00 00
#----------- Mute the DAC digital volume control
w 30 40 0d
#----------- Power down the DAC
w 30 3f c0
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Example Setups
SLAU434 – May 2012
Copyright © 2012, Texas Instruments Incorporated