SLASF36 January 2024 TAC5311-Q1
ADVANCE INFORMATION
All audio data converters require a DC reference voltage. The TAC5311-Q1 achieves its low-noise performance by internally generating a low-noise reference voltage. This reference voltage is generated using a band-gap circuit with good PSRR performance. This audio converter reference voltage must be filtered externally using a minimum 1µF capacitor connected from the VREF pin to the analog ground (VSS).
To achieve low power consumption, this audio reference block is powered down in sleep mode or software shutdown. When exiting sleep mode, the audio reference block should be powered up by setting SLEEP_EXIT_VREF_EN(P0_R2_D3) to 1'b1. An internal fast-charge scheme helps the VREF pin to settle to its steady-state voltage faster (a function of the decoupling capacitor on the VREF pin). This time is approximately equal to 3.5ms when using a 1μF decoupling capacitor. If a higher value of the decoupling capacitor is used on the VREF pin, the fast-charge setting must be reconfigured using the VREF_QCHG, P0_R2_D[5:4] register bits, which support options of 3.5ms (default), 10ms, 50ms, or 100ms.