Hi Sir,
Customer encounters a noise problem with TLV320AIC3104's DAC output (pin 27, pin 28) which needs product line's tips to identify the potential issue:
1. No noise problem with ADC to Line-Out path (confirmed by maximum setting on register 15, 19, 81. 86)
- R19 (Page 0/Register 19: MIC1LP/LINE1LP to Left-ADC Control Register)
- R15 (Page 0/Register 15: Left-ADC PGA Gain Control Register)
- R81 (Page 0/Register 81: PGA_L to LEFT_LOP/M Volume Control Register)
- R86 (Page 0/Register 86: LEFT_LOP/M Output Level Control Register)
2. No noise problem with grounded I2S DIN.
3. Noise was found on Line-Out when noise source (ex: hands) approaching I2S DIN. AIC3104 keeps sending noisy signals with noise source removed. Noise problem could be solved by toggle the register 37 off and on again.
- R37 (Page 0/Register 37: DAC Power and Output Driver Control Register)
Pls let me know if product line needs more information for trouble shooting. I can send schematic by Email as needed.
Thank you and Best regards,
Wayne Chen
05/22/2018