Multimedia ICs
Audio digital delay (KARAOKE echo)
BU9252S / BU9252F
The BU9252S and BU9252F are digital delays specifically for Karaoke systems. Each has an internal sample hold
circuit, an 8-bit A / D and D / A converter and 2kB SRAM, and allows for the selection of one of eight delay times just
by attaching an inexpensive ceramic resonator.
A digital echo system can be formed by using either of these ICs together with the BA7725S or BA7725FS.
•
Applications system
Karaoke echo
Electronic circuits that require signal delays
•
Featuresdigital delay circuit.
1) Internal
2) Internal 8-bit A / D converter. Sample rate. (14.22kHz
when f
OSC
= 455kHz).
3) Internal 2k bytes data SRAM.
4) Internal 8-bit D / A converter.
5) CMOS design for low power consumption.
6) Internal sample hold circuit.
7) Internal feedback resistors and capacitors for oscilla-
tor circuits.
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Block diagram
18
V
DD
17
16
15
14
13
12
11
10
GND
9
OSCO
TDO0
TDO1
OSCI
DCNT2
8
TST0
TST1
TST2
TDIN
TEST CIRCUIT
8
×
2k SRAM
8bit
A/D
8bit
D/A
ADDRESS COUNTER
AND
MAIN TIMING
1
2
S/H
3
4
5
6
DCNT0
DCNT1
S/H
AGND
A
IN
AV
DD
A
OUT
7
1
ROHM [ ROHM ]
