JAJSNO6 December 2023 TAC5142
ADVANCE INFORMATION
The device supports simultaneous recording of up to two channels using the high-performance stereo ADC. The device consists of two pairs of analog input pins (INxP and INxM) which can be configured in single-ended or differential input mode by setting MD4 and MD5 pins. The input source for the analog pins can be from electret condenser analog microphones, micro electrical-mechanical system (MEMS) analog microphones, or line-in (auxiliary) inputs from the system board.
The voice or audio signal inputs can be capacitively coupled (AC-coupled) or DC-coupled to the device. For best distortion performance, use of low-voltage coefficient capacitors for AC-coupling is recommended. The typical input impedance for the TAC5142 is 40 kΩ for the INxP or INxM pins. The value of the coupling capacitor in AC-coupled mode must be chosen so that the high-pass filter formed by the coupling capacitor and the input impedance do not affect the signal content. Before proper recording can begin, this coupling capacitor must be charged up to the common-mode voltage at power-up. To enable quick charging, the device has a quick charge scheme to speed up the charging of the coupling capacitor at power-up. Quick-charge time for the device is configured using MD3 pin along with digital HPF. Refer to Table 8-8 for quick charge time based on MD3 pin configuration.
The device supports playback of two channels using the high-performance stereo DAC. The device consists of two pairs of analog output pins (OUTxP and OUTxM) which can be configured in single-ended or differential input mode by setting MD4 and MD5 pins. The input source for these channels is from TDM/I2S.
Table 8-8 shows the analog input output configuration modes available with MD4 and MD5 configuration
MD4 | MD5 | ANALOG INPUT CONFIGURATION | ANALOG OUTPUT CONFIGURATION |
---|---|---|---|
Low | Low | Differential input; AC-Coupled only | Differential Output; Lineout load only |
Low | High | Differential input; AC or DC-Coupled | Differential Output; Receiver or Lineout load |
High | Low | Single Ended Input on INxP | Single ended output; Lineout only |
High | High | Single Ended Input on INxP | Pseudo differential output; Headphone or Lineout load |