SLASFD9 April 2025 TAC5301-Q1
PRODUCTION DATA
In addition to the gain calibration, the phase delay in each record channel can be finely calibrated or adjusted in steps of one modulator clock cycle for a cycle range of 1 to 63 for the phase error. The modulator clock for analog and digital microphones is set independantly. For analog microphones, the clock is used for ADC MOD CLK, and is 3.072MHz (the output data sample rate is multiples or submultiples of 48kHz) or 2.8224MHz (the output data sample rate is multiples or submultiples of 44.1kHz) in default configurations. For power savings, the ADC modulator clock can also be reduced to 1.536MHz (the output data sample rate is multiples or submultiples of 48kHz) or 1.4112MHz (the output data sample rate is multiples or submultiples of 44.1kHz) by using ADC_CLK_BY2_MODE (B0_P78_D[7]) register bit. The programmable channel phase calibration feature is very useful for many applications that must match the phase with fine resolution between each channel, including any phase mismatch across channels resulting from external components or microphones. Table 6-14 shows the available programmable options for channel phase calibration.
| P0_R84_D[7:2] : ADC_CH1_PCAL[5:0] | CHANNEL PHASE CALIBRATION SETTING FOR INPUT CHANNEL 1 |
|---|---|
| 00 0000 = 0d (default) | No phase calibration |
| 00 0001 = 1d | Input channel 1 phase calibration delay is set to one cycle of the modulator clock |
| … | … |
| 11 1111 = 63d | Input channel 1 phase calibration delay is set to 63 cycles of the modulator clock |
Similarly, the channel phase calibration setting for input channel 2 can be configured using the ADC_CH2_PCAL (P0_R89_D[7:2]) register bits.