ROHM BU9255FS, BU9253AS Datasheet
1
Multimedia ICs
KARAOKE echo IC
BU9253AS / BU9253FS / BU9255FS
The BU9253AS, BU9253FS and BU9255FS are single-chip ICs that contain all the components needed to configure
a KARAOKE echo system: an A / D and D / A converter, SRAM, LPF, and mixer for mixing source signals. With
these ICs, an echo function can be configured easily and with minimum external components.
•
Applications
KARAOKE functions for portable stereo sets, mini component stereo sets, video CDs and DVDs, etc.
•
Features
1) Echo mixing ratio is adjustable with a DC voltage.
2) A second order LPF can be configured with the
internal amplifier and an attached capacitor and
resistor.
3) Delay time of 131ms. (when f
CLK = 357kHz)
4) Internal mute function.
5) Single power supply (5V).
•
Block diagram
BU9253FS / BU9255FS
BU9253AS
1
COUNTER
V
CC
A / D
SRAM
D / A
OSC
2345678
16 15 14 13 12 11 10 9
MIX
123456789
COUNTER
V
CC
A / D
SRAM
D / A
OSC
16 15 14 13 12 11 10
MIX
18
17
+
–
+
–
+
–
+
–
2
Multimedia ICs BU9253AS / BU9253FS / BU9255FS
•
Pin descriptions
BU9253FS / BU9255FS BU9253AS
Pin No. Pin name Function
1
GND
2
ECHO VR
3
BIAS
4
DAINT IN
5
DAINT OUT
6
DALPF IN
7
DALPF OUT
8
MIX OUT
9
MIX IN
10
ADLPF IN
11
ADLPF OUT
12
ADINT OUT
13
ADINT IN
14
V
CC
15
MUTE
16
CR
Analog DC bias
DA integrator input
Echo level DC control
DA integrator output
DA LPF input
DA LPF output
Source sound and echo sound
mixing output
Mixing amplifier source sound input
AD LPF input
AD LPF output
AD integrator output
AD integrator input
Vcc
Mute control
Oscillator output
Ground
•
Absolute maximum ratings (Ta = 25°C)
Parameter Symbol Limits Unit
Applied voltage V
CC 7V
Power dissipation
Pd
500
∗
1
600
∗
2
BU9253FS
BU9253AS
500
∗
1
BU9255FS
mW
Operating temperature Topr – 10 ~
+ 70 °C
Storage temperature Topr – 55 ~
+ 125 °C
Input voltage
VIN – 0.3 ~ VCC + 0.3 V
∗
1 Reduced by 5.0mW for each increase in Ta of 1°C over 25°C.
∗
2 Reduced by 6.0mW for each increase in Ta of 1°C over 25°C.
•
Recommended operating conditions (Ta = 25°C)
Parameter
Power supply voltage V
CC 4.0 5.5 V5.0
Symbol Min. Typ. Max. Unit
Pin No. Pin name Function
1
GND
2
ECHO VR
3
N.C.
4
BIAS
5
DAINT IN
6
DAINT OUT
7
DALPF IN
8
DALPF OUT
9
MIX OUT
10
MIX IN
11
ADLPF IN
12
ADLPF OUT
13
ADINT OUT
14
ADINT IN
15
V
CC
16
17
18
N.C.
MUTE
CR
Ground
Echo level DC control
Internally
Analog DC bias
DA integrator input
DA integrator output
DA LPF input
DA LPF output
Source sound and echo sound
mixing output
Mixing amplifier source sound input
AD LPF input
AD LPF output
AD integrator output
AD integrator input
Vcc
Internally
Mute control
Oscillator output
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