CS43130 Datasheet, PDF (39/137 Pages) Cirrus Logic – 130-dB, 32-Bit High-Performance DAC with Integrated Headphone Driver

XTI/MCLK
MCLK_SRC_SEL p. 96
RCO
Internal
PLL
PDN_PLL p. 97
CS43130
4.7 Clock Output and Fractional-N PLL
Internal MCLK
MCLK_INT p. 96
CLKOUT_DIV p. 100
÷
CLKOUT
CLKOUT_SEL p. 100
Figure 4-16. MCLK Source Switching
A source to MCLK_INT, either the XTAL (or external MCLK), the PLL, or the RCO, must be provided as long as the
CS43130 is operating; otherwise, the CS43130 enters a nonresponsive state, and I²C SDA signal can be held low. The
only way to recover from this nonresponsive state is either through a reset or a POR event. Switching MCLK sources
during DAC operation causes audible artifacts, but does not put the device in an unrecoverable state. In an MCLK
source-switching event, the intended clock source must be present and ready before switching occurs.
After POR or reset event, RCO is selected as default source of MCLK_INT.
4.6.1.1 Internal RC Oscillator
As described in Section 4.6.1, the CS43130 includes an internal RC oscillator that can be used as a clock source for
peripheral circuit such as control port or charge pump.
4.7 Clock Output and Fractional-N PLL
The CS43130 clock output can be used as a master clock for other data-conversion or signal-processing components,
which requires synchronous timing to the CS43130.
The CLKOUT output is enabled by clearing PDN_CLKOUT.
XTI/MCLK
PLL_OUT
CLKOUT_DIV
÷
CLKOUT
CLKOUT_SEL p. 100
Figure 4-17. CLKOUT Source Selection
Once enabled, CLKOUT is generated either from the internal crystal oscillator output (when used) or from the integrated
fractional-N PLL; it can be selected by CLKOUT_SEL. CLKOUT_DIV can be used to set /2, /3, /4, or /8 to divide the
selected clock source to targeted frequency.
4.7.1 Fractional-N PLL
The CS43130 has an integrated fractional-N PLL to support the clocking requirements of various applications. This PLL
can be enabled or disabled by clearing or setting PDN_PLL bit. The input reference clock for the PLL is signal on XTI/
MCLK pin (crystal-generated or external-feed).
DS1073F1
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