SLASF28A December 2023 – November 2024 TAC5142
PRODUCTION DATA
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 42kΩ for the INxP or INxM pins with ±20% variation. 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 when operating in the I2S/LJ target mode. This input cap quick charge setting can be enabled by configuring the MD3 pin. The MD3 pin also configures the digital HPF cut-off frequency of the ADC signal path when the device is operating in I2S/LJ target mode as described in Table 7-11.
For optimal performance, the common-mode variation at the device input should be limited to less than 100mVpp for AC-coupled settings. For applications that cannot avoid large common-mode fluctuations, the device offers the modes to configure the device for higher common-mode tolerance for both single-ended and differential applications.
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/LJ interface.
Table 7-11 shows the analog input output configuration modes available with MD4 and MD5 configuration.
MD5 | MD4 | ANALOG INPUT CONFIGURATION | ANALOG OUTPUT CONFIGURATION |
---|---|---|---|
Low | Low | Differential input; AC-Coupled only | Differential Output; Line-out only |
Low | High | Differential input; AC or DC-Coupled with High Common Mode Tolerance | Differential Output; Receiver/Headphone load or Line-out |
High | Low | Single Ended Input on INxP; AC-Coupled only | Single-ended output; Line-out only |
High | High | Single Ended Input on INxP; AC or DC-Coupled with High Common Mode Tolerance | Pseudo-differential output with external common-mode sense; Headphone load only |
Figure 7-6 to Figure 7-9 show the typical configuration diagrams for the various input configuration modes and Figure 7-10 to Figure 7-12 show the typical configuration diagrams for the various output modes.