[AK4634]
b) PLL reference clock: BICK or LRCK pin
Sampling frequency corresponds to 7.35kHz to 48kHz by changing FS3-0 bits. (Table 6)
AK4634
MCKO
DSP or μP
MCKI
16fs, 32fs, 64fs
BCLK
FCK
BICK
FCK
1fs
SDTI
SDTO
SDTI
SDTO
Figure 21 PLL Slave Mode 2 (PLL Reference Clock: BICK pin)
AK4634
MCKO
DSP or μP
MCKI
≥16fs
BCLK
FCK
BICK
FCK
1fs
SDTI
SDTO
SDTI
SDTO
Figure 22. PLL Slave Mode 2 (PLL Reference Clock: FCK pin)
The external clocks (MCKI, BICK and FCK) should always be present whenever the ADC or DAC or SPK or
Programmable Filter is in operation (PMADC bit = “1”, PMDAC bit = “1”, PMSPK bit = “1”, PMPFIL bit = “1”). If these
clocks are not provided, the AK4634 may draw excess current and it is not possible to operate properly because utilizes
dynamic refreshed logic internally. If the external clocks are not present, the ADC, DAC, SPK and Programmable Filter
should be in the power-down mode.(PMADC = PMDAC = PMPFIL bits = “0”).
MS0983-E-00
2008/07
- 28 -
AKM [ ASAHI KASEI MICROSYSTEMS ]
