BU9253AS_05 Datasheet, PDF (10/17 Pages) Rohm – Karaoke/Surround Digital Echo

・Delay time control circuit
This circuit controls delay time. -8 delay time can be selected by register.
D0
D1
D2
Delay time (Sampling frequency)
L
L
L
9.2msec (2MHz / 6)
H
L
L
15.4msec (2MHz / 6)
L
H
L
21.1msec (2MHz / 6)
H
H
L
30.0msec (2MHz / 6)
L
L
H
48.0msec (2MHz / 6)
H
L
H
96.0msec (2MHz / 12)
L
H
H
144.0msec (2MHz / 18)
H
H
H
192.0msec (2MHz / 24)
LPF cutoff frequency
7kHz
3kHz
・Delay signal volume circuit
This is the delay signal volume circuit. 8 volume setting can be selected by register.
D8
D9 D10
L
L
L
H
L
L
L
H
L
H
H
L
L
L
H
H
L
H
L
H
H
H
H
H
DLYVOL
+3dB
0dB
-3dB
-6dB
-9dB
-12dB
-15dB
-∞dB
・Feedback volume circuit
This is the feedback volume circuit. 8 feedback volume setting can be selected by register.
D11 D12 D13
L
L
L
H
L
L
L
H
L
H
H
L
L
L
H
H
L
H
L
H
H
H
H
H
FBVOL
-3dB
-5dB
-7dB
-9dB
-11dB
-13dB
-15dB
-∞dB
・Input mixer･selector circuit
This mixes MIC IN, LCIN, RCIN, VOIN signals, and selects the output path by selector.
LCIN
RCIN
MRCIN
VOIN
＋
－＋
ISEL
FBVOL
＋
＋
OSEL
#2
＋
ADC
デ^Deィ^laレ^yイ
DAC
OSEL
#3
＋
LCOUT
RCOUT
OSEL
#1
－
DLY
DOSW
VOL
DSIG
Fig.31 Input mixer selector circuit
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