BD34700FV Datasheet, PDF (19/31 Pages) Rohm – Micro-step volume can reduce the switching pop noise when volume changes

BD34700FV
Volume changing needs the time that is following Figure. (Ex. It selected 11msec, 22msec need.)
Current XdB
Send YdB
Changed YdB
[A->B switching time] [B->A switching time]
Datasheet
Prossing Time
Figure 11. About [A→B switching-time] [B→A switching-time]
Base clock is able to change Internal Oscillator Frequency. For example, when Base clock select ×1/2,
A->B and B->A switching time is to be two times. (ex. 11msec->22msec)
○Caution on send data
When send the same channel data among the switching process, internal operation is as below.
①
CLK
Inv alid data
② ③④
DATA
IC processing
Processing time per 1
A->B switching time B->A switching t ime
Processing time per 1
A->B switching time B->A switching time
Output
Initial
Initial → ① → ②
②→ ④
Figure 12. The switching process with send data
②data is sent during A -> B switching time, it is valid.
③data and ④data are sent during B -> A switching time, it is valid at the next processing time.
But ③data is replaced by ④data.
○About pop noise in gain changing
The level of the pop noise sometimes varies in the difference in output DC offset of the inside condition A and B.
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TSZ22111・15・001
19/27
TSZ02201-0C2C0E100060-1-2
06.Aug.2014 Rev.001