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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.
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Applications
Karaoke echo system
Electronic circuits that require signal delays
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Features
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Block diagram
1
S / H
A
IN
AGND
A
OUT
AVDD
DCNT0
DCNT1
DCNT2
GND
V
DD
TST0
TST1
TST2
TDIN
TDO0
TDO1
OSCI
OSCO
S / H
8 × 2k SRAM
ADDRESS COUNTER
AND
MAIN TIMING
8bit
A / D
8bit
D / A
TEST CIRCUIT
2
354
6
7
8
9
18
17
16
15
14
13
12
11
10
1) Internal digital delay circuit.
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 oscillator circuits.
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Multimedia ICs BU9252S / BU9252F
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Pin descriptions
Pin name
1 S / H 10 OSCO
2A
IN 11 OSCI
3 AGND 12 TDO1
4A
OUT 13 TDO0
5AV
DD 14 TDIN
6 DCNT0 15 TST2
7 DCNT1 16 TST1
8 DCNT2 17 TST0
9 GND 18 V
DD
Pin No. Function Pin No. Pin name
Analog input
Analog output
Analog circuit power supply
Delay setting input
Delay setting input
Delay setting input
Function
For attaching sample-and-hold capacitor
Analog circuit ground
Digital circuit ground
Test pin (output)
Test pin (output)
Test pin (input)
Test mode setting
Test mode setting
Test mode setting
Digital circuit power supply
Oscillator pin 1
Oscillator pin 2