AK4128A Datasheet, PDF (36/50 Pages) Asahi Kasei Microsystems – 8ch 216kHz / 24-Bit Asynchronous SRC

[AK4128A]
1. When the frequency of ILRCKx (x=1, 2, 3, 4) at input port is changed without a reset by the PDN pin or RSTN bit.
When the difference of internal oscillator (min. 59.4 MHz, typ. 73.5 MHz) clock number in one ILRCKx cycle
between before an ILRCKx frequency change (FSO/FSI ratio is stabilized) and after the change is more than ±100
for 8cycles, an internal reset is made automatically and sampling frequency ratio detection is executed again.
SDTOx outputs “L” when the internal reset is made, and SRC data is output after “0.5/FSI+8/FSI(O)+156/FSO or
1.5/FSI+8/FSI(O)+156/FSO” (FSI(O) is lower frequency between FSI and FSO).
If the difference of internal oscillator clock number in one ILRCKx cycle between before an ILRCKx frequency
change and after the change is less than ±100 or more than ±100 but shorter than 8cycles, the internal reset is not
executed. In both cases; when ILRCKx frequency is changed immediately without transition time or with transition
time which is not long enough for an internal reset, it takes 5148/FSO (max. 643.5ms @FSO=8kHz) (Note 38)to
output normal SRC data. Distorted data may be output until normal SRC output.
When ILRCKx is stopped, an internal reset is executed automatically. It takes “0.5/FSI+8/FSI(O)+156/FSO or
1.5/FSI+8/FSI(O)+156/FSO” (FSI(O) is lower frequency between FSI and FSO) [s] to output normal SRC data
after ILRCKx is input again.
2. When the frequency of OLRCK at output port is changed without a reset by the PDN pin or RSTN bit.
When the difference of internal oscillator clock number in one OLRCK cycle between before an OLRCK frequency
change (FSO/FSI ratio is stabilized) and after the change is more than ±100 for 8cycles, an internal reset is made
automatically and sampling frequency ratio detection is executed again. SDTOx (x=1, 2, 3, 4)outputs “L” when the
internal reset is made, and SRC data is output after “0.5/FSI+8/FSI(O)+156/FSO or 1.5/FSI+8/FSI(O)+156/FSO”
(FSI(O) is lower frequency between FSI and FSO).
If the difference of internal oscillator clock number in one OLRCK cycle between before an OLRCK frequency
change and after the change is less than ±100 or more than ±100 but shorter than 8cycles, the internal reset is not
executed. It takes 5148/FSO (max. 643.5ms @FSO=8kHz) (Note 38) to output normal SRC data. Distorted data
may be output until normal SRC output.
When OLRCK is stopped, an internal reset is executed automatically. It takes “0.5/FSI+8/FSI(O)+156/FSO or
1.5/FSI+8/FSI(O)+156/FSO” (FSI(O) is lower frequency between FSI and FSO) [s] to output normal SRC data
after ILRCKx is input again.
Note 38. When FSO=8kHz and FSO/FSI ratio is changed from 1/6 to 1/5.99. It is 160.9ms when FSO=32kHz and FSO/fSI
ratio is changed from 1/6 to 1/5.99.
MS1242-E-00
- 36 -
2010/09