SLASF29 January 2022 TAA5242
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 TAA5242 is 5 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.
Table 8-4 shows the analog input configuration modes available with MD4 and MD5 configuration
MD4 | MD5 | ANALOG INPUT CONFIGURATION |
---|---|---|
Low | Low | Differential input; AC-Coupled only |
Low | High | Differential input; AC or DC-Coupled |
High | Low | Single Ended Input on INxP |
High | High | Differential input; AC or DC-Coupled; Low Power Mode |