BH3541F / BH3544F
Optical disc ICs
Headphone amplifier for CD-ROMs
BH3541F / BH3544F
The BH3541F and BH3544F are digital-source dual headphone amplifiers. The BH3541F has a fixed gain of 0dB and
the BH3544F has a fixed gain of 6dB so that external gain setting is unnecessary. Both the BH3541F and BH3544F have
internal mute functions so that prevention of the popping sound when power is turned on and off is greatly simplified.
Also, these ICs are equipped with thermal shutdown circuits to prevent damage from short circuits.
Product name
BH3541F
BH3544F
Fixed gain
0dB
6dB
!
!
!
!Applications
Devices that use the headphone output from CD-ROMs, CDs, MDs, personal computers, notebook computers,
camcorders, etc.
!
!
!
!Features
1) Internal mute function to prevent popping sounds when the power is turned on and off.
2) Built-in thermal shutdown circuit (150
C) to prevent damage to the IC if a short circuit occurs.
3) Compact SOP8 pin package.
!
!
!
!Absolute maximum ratings
(Ta = 25
C)
Parameter
Symbol
Limits
Unit
Applied voltage
V
Max
7.0
V
Power dissipation
Pd
450
mW
Operating temperature
Topr
-
25 ~
+
75
Storage temperature
Tstg
-
55 ~
+
125
C
C
Reduced by 4.5mW for each increase in Ta of 1
C over 25
C.
!
!
!
!Recommended operating conditions
(Ta = 25
C)
Parameter
Power supply voltage
Symbol
Min.
Typ.
Max.
Unit
V
CC
2.8
-
6.5
V
BH3541F / BH3544F
Optical disc ICs
!
!
!
!Block diagram
5
6
7
8
3
4
V
CC
OUT2
BIAS
IN2
180k
(90k)
180k
(90k)
0dB
(6dB)
0dB
(6dB)
BIAS
MUTE
TSD
2
1
OUT1
MUTE
IN1
GND
+
+
( ) The values in parenthesis are for the BH3544F.
BH3541F / BH3544F
Optical disc ICs
!
!
!
!Pin descriptions
Pin No.
Pin name
Internal equivalent circuit
I / O
Pin voltage
Function
1
OUT1
O
2.1V
Output pin
7
OUT2
O
2.1V
2
MUTE
I
0.1V
3
IN1
I
2.1V
5
IN2
I
2.1V
Input pin
6
BIAS
I / O
2.1V
4
GND
I
-
1
V
CC
10k
7
2
V
CC
190k
3
5
6
V
CC
V
CC
180k
BIAS
BIAS
60k
60k
(V
CC
=
5V)
(When open)
(V
CC
=5V)
(V
CC
=5V)
8
I
-
V
CC
Mute control pin
(set to low for prevention of
popping noise when power
is turned on and off).
Operating : High
Muting : Low (open)
Bias pin
(the external 47
F
capacitor also serves as the
anti-pop time constant,
therefore make the proper
considerations be changing
it).
BH3541F / BH3544F
Optical disc ICs
!
!
!
!Electrical characteristics
(unless otherwise noted, Ta = 25
C, V
CC
= 5.0V, R
L
= 32
, BH3541F : V
IN
= 0dBV,
BH3544F : V
IN
=
-6dBV, and f = 1kHz)
Parameter
BH3541F
BH3544F
Symbol
Min.
Typ.
Max.
Unit
I
Q
4
7
10
mA
V
TM
0.3
0.7
1.6
V
THD
-
0.02
0.1
%
RR
50
57
-
dB
4
6
0
8
dB
G
VC
-
0.5
62
31
-
93
-
G
VC
-
2
2
dB
dB
P
O1
25
-
mW
P
O2
50
0
-
0.5
mW
V
NO
-
-
85
dBV
ATT
CS
70
82
80
90
-
dB
dB
Conditions
-
-
-
-
Rg
=
0
f
RR
=
100Hz, V
RR
=-
20dBV
BW
=
20~20kHz, Rg
=
0
R
L
=
16
, THD
<
0.1%
Rg
=
0
R
L
=
32
, THD
<
0.1%
BW
=
20~20kHz
V
IN
=
0Vrms
Quiescent current
Mute pin control voltage
Voltage gain
Voltage gain difference between channels
Channel separation
Mute attenuation
Ripple rejection
Total harmonic distortion
Rated output 1
Rated output 2
Output noise voltage
!
!
!
!Measurement circuit
Fig.1
5
6
7
8
3
4
V
CC
OUT2
BIAS
IN2
47
180k
(90k)
180k
(90k)
0dB
(6dB)
0dB
(6dB)
BIAS
MUTE
TSD
2
1
OUT1
MUTE
IN1
GND
1
V
IN
1
330
V
16
330
V
A
1
1
2
SW5
V
IN
2
V
7AC
SW7
1
2
32
10
CV
CC
IQ
SW8B
1
2
SW8A
V
RR
V
CC
32
16
SW1
1
2
V
1AC
V
TM
SW3
1
2
+
+
+
+
+
+
( ) The values in parenthesis are for the BH3544F.
BH3541F / BH3544F
Optical disc ICs
!
!
!
!Measurement conditions
I
Q
1
1
1
1
2
OFF
IQ
Signal
SW table
SW1 SW3
SW5 SW7 SW8A SW8B
Monitor
Conditions
-
V
TM
-
-
-
-
-
-
-
-
-
G
VC
1
2
2
1
2
ON
V1AC, V2AC
V1AC, V2AC
V1AC, V2AC
V1AC, V2AC
V1AC, V2AC
V1AC, V2AC
V1AC, V2AC
V1AC, V2AC
V1AC, V2AC
f
=
1kHz, V
IN
1/2
=
0dBV (V
IN
1/2
=-
6dBV),
VTM
=
1.6V
G
VC
-
-
-
-
-
-
-
GVC1
-
GVC2
THD
1
2
2
1
2
ON
fin
=
1kHz, V
IN
1/2
=
0dBV (V
IN
1/2
=-
6dBV),
VTM
=
1.6V
P
O1
1
2
2
1
2
ON
fin
=
1kHz, V
IN
1/2
=
0dBV (V
IN
1/2
=-
6dBV),
VTM
=
1.6V
P
O2
2
2
2
2
2
ON
fin
=
1kHz, V
IN
1/2
=
0dBV (V
IN
1/2
=-
6dBV),
VTM
=
1.6V
V
NO
1
1
1
1
2
ON
CS
1
1
1
2
2
1
1
1
2
2
ON
ON
fin
=
1kHz, V
IN
2
=
0dBV (V
IN
2
=-
6dBV),
VTM
=
1.6V
fin
=
1kHz, V
IN
1
=
0dBV (V
IN
1
=-
6dBV),
VTM
=
1.6V
ATT
1
2
2
1
2
ON
fin
=
1kHz, V
IN
1/2
=
0dBV (V
IN
1/2
=-
6dBV),
VTM
=
0.3VB
RR
1
1
1
1
1
ON
V
RR
=-
20dBV, f
RR
=
100Hz
( ) The values in parenthesis are for the BH3544F.
!
!
!
!Circuit operation
Rising edge timing
OUT
VMUTE
V
CC
A
Rise period
Play period
Rise period
A
C
B
A : MUTE period (use with MUTE
=
Low to prevent the popping noise when the power is turned on and off).
B : MUTE release time (used to prevent the popping noise at the release of MUTE with the external C2 and R2,
and therefore possesses a time constant, so be careful of the timing).
C : MUTE start time (also possesses a time constant like the MUTE release time).
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