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Headphone Amplifiers
Standard
Headphone Amplifiers
BH3541F,BH3544F,BH3547F,BH3548F
●Description
BH3541F, BH3544F, BH3547F, BH3548F is headphone amplifiers suitable for portable products.
BH3541F has a fixed gain of 0 dB and BH3544F, BH3547F, BH3548F has a fixed gain of 6 dB.
External resistors for gain setting are not needed. Package of BH3541F, BH3544F, BH3547F, BH3548F is pin-to-pin
compatible (SOP8), enable to replace each other easily.
BH3541F, BH3544F, BH3547F, BH3548F also has mute functions that make it easy to prevent pop noise when power
supply turns on/off. Moreover, thermal shutdown function is built-in.
BH3541F, BH3544F, BH3547F can drive 16/32Ω load, BH3548F can drive 8/16/32Ω. So, BH3548F is suitable for 8Ω
receiver.
●Features
1) Built-in mute function for preventing pop noise when power supply turns on/off
2) Built-in thermal shutdown function
3) BH3541F, BH3544F, BH3547F, BH3548F are pin-to-pin compatible
4) SOP8 small package
●Applications
TV, Desktop PC, Notebook PC, Camcorder and other equipment having headphone output
●Line up
Part No. BH3541F BH3544F BH3547F BH3548F Unit
Supply voltage +2.8 ～ +6.5 +4.5 ～ +5.5 +4.0 ～ +5.5 V
Quiescent current 7.0 3.7 6.5 mA
Amplifier gain 0 6 dB
Output [RL=16Ω] 62 77 62 mW
load impedance 16 / 32 8/16/32 Ω
Operating temperature range -25 ～ +75 -40 ～ +85 ℃
●Absolute maximum ratings(Ta=25°C)
Parameter Symbol Ratings Unit
BH3541F,BH3544F,BH3547F,BH3548F
Applied voltage VCC 7.0 V
Power dissipation Pd 550
*1 mW
Storage temperature Tstg - 55～+125 °C
*1 Derating is done at 5.5mW/°C above Ta=25°C. (When mounted on a 70mm×70mm×1.6mm PCB board, FR4)
●Operating conditions (Ta=25°C)
Parameter Symbol Limits Unit
BH3541F,BH3544F BH3547F BH3548F
Supply voltage VCC +2.8 ～ +6.5 +4.5 ～ +6.5 +4.0 ～ +5.5 V
Temperature Range Topr -25～+75 -40 ～ +85 ℃
* These product are not designed for protection against radioactive rays.
No.10102EAT02
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Technical Note
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BH3541F,BH3544F,BH3547F,BH3548F
●Electrical characteristics (Unless otherwise noted, Ta=25°C,VCC=5V,RL=32Ω,f=1kHz,BW=400～30kHz
BH3541F : VIN=0dBV, BH3544F, BH3547F, BH3548F : VIN =-6dBV)
Parameter Symbol Limits(TYP.) Unit Conditions
BH3541F BH3544F BH3547F BH3548F
Quiescent current IQ 7 3.7 6.5 mA VIN=0Vrms
Mute pin control voltage H VTMH 1.6< V Mute OFF
Mute pin control voltage L VTML <0.3 V Mute ON
Gain GVC 0 6 dB -
Gain difference between
channels ΔGVC 0 dB -
Total harmonic distortion THD 0.02 0.05 0.02 % BW=20～20kHz
Rated output 1 PO1 31 46 31 mW
RL=32Ω,THD<0.1%
(BH3541F,BH3544F,BH3548F)
RL=32Ω,THD＜0.3%
(BH3547F)
Rated output 2 PO2 62 77 62 mW
RL=16Ω,THD<0.1%
(BH3541F,BH3544F,BH3548F)
RL=16Ω,THD＜0.5%
(BH3547F)
Rated output 3 PO3 - 120 mW RL=8Ω,THD＜0.25%
(BH3548F)
Output noise voltage VNO -93 dBV BW=20～20kHz,Rg=0Ω
Channel separation CS -90 -87 -90 dB Rg=0Ω
Mute attenuation ATT -80 dB Rg=0Ω
Ripple rejection RR -57 dB fRR=100Hz,VRR=-20dBV
Input resistance Rin 180 90 kΩ -
●Reference data
BH3541F/BH3544F BH3541F/BH3544F BH3541F/BH3544F
Fig. 1 Quiescent current vs.
power supply voltage
Fig. 2 in DC current vs.
power supply voltage
Fig. 3 Output voltage vs.
Mute control voltage
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Technical Note
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BH3541F,BH3544F,BH3547F,BH3548F
●Reference data (Continued)
BH3541F/BH3544F BH3541F/BH3544F BH3541F/BH3544F
40
0.001
TOTAL HARMONIC DISTORTION : THD(%)
OUTPUT VOLTAGE : V
O
(dBV)
0.01
10
30 20 10 10
0.1
1
0
f100H
Z
f1kH
Z
f10kH
Z
Ta25C
R
L
32
V
CC
5V
40
0.001
TOTAL HARMONIC DISTORTION : THD (%)
OUTPUT VOLTAGE: V
O
(dBV)
0.01
10
30 20 10 10
0.1
1
0
f100H
Z
f1kH
Z
f10kH
Z
Ta25C
R
L
32
V
CC
3V
Fig. 4 Voltage gain vs. frequency Fig. 5 Total harmonic distortion vs.
output voltage (1)
Fig. 6 Total harmonic distortion vs.
output voltage (2)
BH3541F/BH3544F BH3541F/BH3544F BH3541F/BH3544F
Fig. 7 Total harmonic distortion vs.
output voltage (3)
Fig. 8 Total harmonic distortion vs.
output voltage (4)
Fig. 9 Channel separation vs.
frequency
BH3541F/BH3544F BH3541F/BH3544F BH3541F/BH3544F
Fig. 10 MUTE attenuation vs. frequency Fig. 11 Ripple rejection vs. frequency Fig. 12 Ripple rejection vs.
power supply voltage
TOTAL HARMONIC DISTORTION : THD (%)
TOTAL HARMONIC DISTORTION : THD (%)
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Technical Note
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BH3541F,BH3544F,BH3547F,BH3548F
5
678
3 4
VCC OUT2 BIAS IN2
180k
(90k)
180k
(9 0k )
0dB
(6dB)
0dB
(6dB)
BIAS
MUTE
TSD
2 1
OU T1 MUTE IN1 GND
●Block diagram
Fig. 13
●Measurement circuit
Fig. 14
( ) are BH3544F, BH3547F, BH3548F values.
( ) are BH3544F, BH3547F, BH3548F values.
8 7 6 5
1 2 3 4
BIAS
++
180k
(90k)
180k
(90k)
MUTE
TSD
0dB
(6dB)
0dB
(6dB)
R5 1μ 1
2
VIN2
SW5
47μ
IN2BIASVCC
CVCC
10μ
V
330μ
V7AC
1
2
32
16
330μ
V
1
2
32
16
SW7
SW1
AIQ
SW8B
12
SWBA
VRR
VCC
V1AC
OUT1 MUTE IN1 GND
1μ 1
2
VIN1
SW3
R3
OUT2
VTM
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Technical Note
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BH3541F,BH3544F,BH3547F,BH3548F
●Terminal Equivalent Circuit / Description
Pin
No.
Pin
Name I /O Pin voltage
Equivalent circuit
Function
BH3544F,BH3547F,BH3548F BH3547F
1
7
OUT1
OUT2
O 2.1V
(VCC=5V)
Output pin
2 MUTE I
0.1V
(When open)
Mute control pin
Mute on:Hi
Mute off:Lo (open)
3
5
IN1
IN2
I 2.1V
(VCC=5V)
Input pin
6 BIAS I/O 2.1V
(VCC=5V)
Bias pin
(Since the 47 µF
externally attached
capacitor also serves
as the time constant for
pop noise
countermeasures,
evaluate adequately
when changing it.)
4 GND I - - - GND pin
8 VCC I - - - Power supply pin
※The figure in the pin explanation and input/output equivalent circuit is reference value, it doesn’t guarantee the value.
200k
2
VCC
190k
2
VCC
BIAS
6
60k
60k
VCC VCC
BIAS
6
70k
64k
VCC VCC
10k
1
7
1
7
10k
1
7
1
7
3
5 90k
BIAS
VCC
3
5 180k
VCC
BIAS
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Technical Note
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BH3541F,BH3544F,BH3547F,BH3548F
●Application circuit
5
6
7
8
3 4
V
CC OUT2 BIAS IN2
47
µ
1
µ
V
IN
2
180k
(90k)
180k
(90k)
0dB
(6dB)
0dB
(6dB)
BIAS
MUTE
TSD
2 1
OUT1 MUTE IN1 GND
1
µ
V
IN
1
1
µ
100k
330
µ
10
VMUTE
H : Active
L : Mute
330
µ
V
CC
R5
C5
C6
C7
C8
C1
C2
C3
R3
R2
µ
+
+
+
+
Fig. 15
●Description of external components.
1) Input coupling capacitors (C3, C5)
These are determined according to the lower cutoff frequency Moreover, since lowering the capacitance can cause
the occurrence of pop noise, when changing this, determine it after adequate checking.
Since the input impedance of the BH3541F is 180kΩ and that of the BH3544F,BH3547F,BH3548F is 90kΩ, these are
found by the expressions below, although drift, temperature characteristics, and other considerations are necessary.
(Layered ceramic capacitors are recommended.)
C3(C5)=1/(2π×180kΩ×fc) [BH3541F]
C3(C5)=1/(2π× 90kΩ×fc) [BH3544Ｆ,BH3547F,BH3548F]
2) Bias capacitor (C6)
When VCC=5V, 47μF is recommended. Since lowering the capacitance too much can cause worsening of electrical
characteristics or the occurrence of pop noise, when changing this, determine it after checking this adequately.
3) Mute pin pop noise countermeasures (R2, C2)
Since the BH3541F,BH3544F,BH3548F has an impedance of 190kΩ against GND and the BH3547F has 200kΩ, it may
be impossible to cancel mute mode if R2 is made too large.
4) Output coupling capacitors (C1, C7)
These are determined by the lower cutoff frequency. If RL is the output load resistance (assuming a resistance RX is
put in for output protection or current restriction), these are found by the expression below.
C1(C7)=1/(2π×(RL+Rｘ)×
5) Input gain adjustment resistances (R3, R5) (BH3544F,BH3547F)
Externally attached resistances (R3, R5) make input gain adjustment possible. The gain found by the expression
below can be set.
GVC=6+20log(90kΩ/(90kΩ+R3[R5])) [dB]
When input gain is not accommodated, these resistors have no use.
●Notes for use
1) Numbers and data in entries are representative design values and are not guaranteed values of the items.
2) Although we are confident in recommending the sample application circuits, carefully check their characteristics further
when using them. When modifying externally attached component constants before use, determine them so that they
have sufficient margins by taking into account variations in externally attached components and the Rohm LSI, not only
for static characteristics but also including transient characteristics.
3) Absolute maximum ratings
If applied voltage, operating temperature range, or other absolute maximum ratings are exceeded, the LSI may be
damaged. Do not apply voltages or temperatures that exceed the absolute maximum ratings. If you think of a case in
which absolute maximum ratings are exceeded, enforce fuses or other physical safety measures and investigate how
not to apply the conditions under which absolute maximum ratings are exceeded to the LSI.
( ) are BH3544F, BH3547F, BH3548F values.
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Technical Note
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BH3541F,BH3544F,BH3547F,BH3548F
4) GND potential
Make the GND pin voltage such that it is the lowest voltage even when operating below it. Actually confirm that the
voltage of each pin does not become a lower voltage than the GND pin, including transient phenomena.
5) Thermal design
Perform thermal design in which there are adequate margins by taking into account the allowable power dissipation in
actual states of use.
6) Shorts between pins and misinstallation
When mounting the LSI on a board, pay adequate attention to orientation and placement discrepancies of the LSI.
If it is misinstalled and the power is turned on, the LSI may be damaged. It also may be damaged if it is shorted by a
foreign substance coming between pins of the LSI or between a pin and a power supply or a pin and a GND.
7) Operation in strong magnetic fields
Adequately evaluate use in a strong magnetic field, since there is a possibility of malfunction.
8) Pop noise countermeasures
In order to prevent the pop noise that occurs when the power supply turns ON or OFF, make the rise and fall with
reference to the timing diagram shown below.
1)BH3541F/ BH3544F/ BH3548F
Fig. 16
(A):Mute period (Use as pop noise countermeasure when power supply turns ON/OFF by makingVMUTE=Lo.)
(B):Mute cancellation period (This has a time constant because it is used by the externally attached C2 and R2 as
a pop noise countermeasure on mute cancellation, so be careful of the timing.)
(C):Mute start time (As on cancellation, this has a time constant.)
2)BH3547F
Fig. 17
(A):Before VCC rise (or at the same time as VCC) make mute cancelled (VMUTE=Hi).
(B):Soft mute period (This time can be set by externally attached R2 and C2)
VCC
Vmute
OUT
SG
(
In
p
ut Si
g
nal
)
(Rise time) (PLAY period) (Fall period)
(MUTE period)
(A)
(B)
Rise time
PLAY period Rise time
VCC
OUT
MUTE
A
B C
A
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Technical Note
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BH3541F,BH3544F,BH3547F,BH3548F
●Ordering part number
B H 3 5 4 1 F - E 2
Part No. Part No.
3541
3544
3547
3548
Package
F: SOP8
Packaging and forming specification
E2: Embossed tape and reel
∗
Order quantity needs to be multiple of the minimum quantity.
<Tape and Reel information>
Embossed carrier tapeTape
Quantity
Direction
of feed
The direction is the 1pin of product is at the upper left when you hold
reel on the left hand and you pull out the tape on the right hand
2500pcs
E2
()
Direction of feed
Reel 1pin
(Unit : mm)
SOP8
0.9±0.15
0.3MIN
4
°
+
6
°
−
4
°
0.17 +0.1
-
0.05
0.595
6
43
8
2
5
1
7
5.0±0.2
6.2±0.3
4.4±0.2
(MAX 5.35 include BURR)
1.27
0.11
0.42±0.1
1.5±0.1
S
0.1 S
R1010
A
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"Products"). If you wish to use any such Product, please be sure to refer to the specications,
which can be obtained from ROHM upon request.
Examples of application circuits, circuit constants and any other information contained herein
illustrate the standard usage and operations of the Products. The peripheral conditions must
be taken into account when designing circuits for mass production.
Great care was taken in ensuring the accuracy of the information specied in this document.
However, should you incur any damage arising from any inaccuracy or misprint of such
information, ROHM shall bear no responsibility for such damage.
The technical information specied herein is intended only to show the typical functions of and
examples of application circuits for the Products. ROHM does not grant you, explicitly or
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other parties. ROHM shall bear no responsibility whatsoever for any dispute arising from the
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Please be sure to implement in your equipment using the Products safety measures to guard
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