1/9
www.rohm.com 2012.06 - Rev.C
© 2011 ROHM Co., Ltd. All rights reserved.
Audio Accessory ICs
Preamps with Built-in ALC
BA3308F,BA3308FV
●Description
The BA3308F/FV is a dual preamplifier for recording and playback with ALC (auto level control), developed for stereo radio,
cassette recorders, tape recorders, and other pre amplifiers audio applications.
ALC circuit has a build in rectification circuit with wide adjustable dynamic range, high gain, low distortion amplifiers with
direct coupling and mute circuit, used to cut off pop noise during power on.
Available in SOP14, or SSOP-B14 Packages.
●Features
1) Built-in ALC rectification diode
2) Wide operating p ower supply voltage range (VCC=4.5~14 V)
3) Low current consumption (IQ=3.5mA)
4) High gain (GVO=80dB)
5) Low distortion (THD=0.1%)
6) Low noise (VNIN=1 Vrms)
7) Input coupling capacitor not needed
8) Good ALC channel balance
9) Built-in power supply mute circuit
10) Dynamic range of ALC can be changed by attaching input resistance.
●Applications
Stereo radio, cassette tape recorders, stereo cassette decks, home stereos, music centers, etc.
●Line up matrix
Part No. BA3308F BA3308FV
Package SOP14 SSOP-B14
No.11087ECT01
Technical Note
2/9
BA3308F,BA3308FV
www.rohm.com 2012.06 - Rev.C
© 2011 ROHM Co., Ltd. All rights reserved.
●Absolute maximum ratings(Ta=25℃)
Parameter Symbol Limits Unit
Supply voltage VCC 16 V
Power
dissipation BA3308F Pd 450*1 mW
BA3308FV 350*2
Operating temperature Topr －25～＋75 ℃
Storage temperature Tstg －55～＋125 ℃
*1 Reduce by 4.5 mW/C over 25C, when mounted on a 70mm×70mm×1.6mm PCB board.
*2 Reduce by 3.5 mW/C over 25C
●Operating conditions(Ta=25℃)
Parameter Symbol
Min. Typ. Max. Unit
Supply voltage VCC 4.5 - 14 V
Note: This IC is not designed to be radiation-resistant.
●Electrical characteristics(Unless otherwise noted, Ta=25℃, Vcc=7.0V, f=1kHz, BPF20～20kHz)
Parameter Symbol Min. Typ. Max. Unit Conditions Test
Circuit
Quiescent current IQ 1.5 3.5 4.5 mA VIN=0Vrms Fig.17
Open loop voltage gain GVO 70 80 - dB VOUT=-10dBV Fig.17
Total harmonic distortion THD - 0.1 0.3 % NAB34dB, VOUT=40mVrms Fig.17
Input resistance RIN 15 25 45 k Fig.17
Maximum output voltage VOM 0.6 1.2 - Vrms THD=1% Fig.17
Input conversion noise
voltage VNIN - 1 2 Vrms Rg=2.2k, referenced to NAB 34dB
at 1kHz Fig.17
ALC range ALC 40 45 - dB Rg=3.9 k, VIN＝-70 dBV standard,
THD=3% Fig.17
ALC channel balance ALC - 0 2.5 dB VIN=-60dBV,-30dBV Fig.17
Channel separation CS 60 75 - dB VO=0dBV, NAB 34dB Fig.17
Technical Note
3/9
BA3308F,BA3308FV
www.rohm.com 2012.06 - Rev.C
© 2011 ROHM Co., Ltd. All rights reserved.
NF1
INPUT1
OUTPUT1
GND
ALC
V
CC
OUTPUT2
INPUT2
NF2
ALC
V
cc
1
2
3
4
5
6
7
14
13
12
11
10
9
8
N.C.
N.C.
N.C.
N.C.
N.C.
BA3308F/FV
●Block diagram
Fig.1
Technical Note
4/9
BA3308F,BA3308FV
www.rohm.com 2012.06 - Rev.C
© 2011 ROHM Co., Ltd. All rights reserved.
●Electrical characteristic curves (Reference data)
Fig.2 Quiescent current vs. Fig.3 Quiescent current vs. Fig.4 Voltage gain vs. frequency
power supply voltage ambient temperature
Fig.5 Total harmonic distortion vs. Fig.6 Voltage gain vs. Fig.7 Closed loop voltage gain vs.
frequency supply voltage ambient temperature
Fig.8 Input conversion noise voltage Fig.9 Channel separation vs. Fig.10 ALC characteristics
vs. signal source resistance frequency
Fig.11 Input/output characteristics Fig.12 Ma ximum output voltage vs. Fig.13 Maximum output voltage vs.
power supply voltage load resistance
Technical Note
5/9
BA3308F,BA3308FV
www.rohm.com 2012.06 - Rev.C
© 2011 ROHM Co., Ltd. All rights reserved.
●Description of operations
1. Recording
1) Record amplifier
2) ALC
Fig.5
BA3308 Cont ch2
(ch1)
ch2
(ch1)
ch1
(ch2)
2 (8) 1 (9) 3 (7) 5
3.9k
10F
INPUT
39
18k
1M
100F
10F
22F
OUTPUT
R
1
(R
2
)R
3
(R
4
)
R
5
(R
6
)R
7
(R
8
)
C
1
(C
2
)C
3
(C
4
)
C
5
(C
6
)
C
7
(C
8
)
Fig.14
The BA3308F/FV has an on-chip signal rectifier and electronic
volume needed for ALC. The signal rectifier compares the direct
current output voltage that is superposed in the output stage (1, 7pin)
signal to the reference voltage 4.5VF (≒3V; 1VF is approximately
0.7V) in the comparator circuit and if the output voltage is higher, it
turns the comparator ON to charge the smoothing capacitor C7.
Since the operation point of t he output stage of amplifier c h1 and ch2
is fixed at 3VF, the comparator turns ON when the peak value of the
signal output voltage is 1.5VF (effective value approx. 0.75V). Once
the direct current signal for electronic volume is controlled, ALC
operation starts. The electronic volume, which is connected between
the input line (13, 9pin) and GND, causes the input signal to
attenuate according to the ratio of the e xternal resistance (R1, R2) to
the resistance value of the electronic volume. The ALC range varies
according to the values of R1 and R2. For small ALC variation the
S/N will determinate an adequate ALC rang e is obtained by applying
several k of the R1 and R2. The attack time and recovery time of
ALC are set according to C7 and R7 of 4pin. If the time constants
(C7, R7) are large, the recovery time will be long a nd as C7 becomes
smaller, and the attack time will be shorter.
The BA3308F/FV amplifier of ch1 and ch2 input stage
(13pin, 9pin) can be direct coupled or use coupling
capacitors (C1/C2). The voltage gain of the record amplifier
is determined by GV=R5/R3. The R5/R6, and C3/R3 regulate
control of the pop noise that occurs at power-on (see
“Cautions on use”) and direct current bias fed back is set by
R5/R6 and C5/C6 at the output stage.
13(9) 11(10) 1 (7) 4
Fig.6
ch2
(ch1)
ch2
(ch1)
ch1
(ch2)
ContComp
BA3308
3 (7) 52 (8)
4.5VF
VOUT (DCAC)
3VF
R
7
C
7
R
1
(R
2
)
Fig.15
1 (7) 4 13(9)
Technical Note
6/9
BA3308F,BA3308FV
www.rohm.com 2012.06 - Rev.C
© 2011 ROHM Co., Ltd. All rights reserved.
2. On playback
.
Since amplifier ch1 and ch2 are used as a NAB equalizer
amplifier at playback, a time constant circuit is established in
the NF section (1-11pin, 7-10pin) to obtain NAB
characteristics. The voltage gain at this time is determined b y
the following formula:
GV = │R11＋R9/ (│＋jC9・R9)│/R3
Obtain the necessary gain by regulating the (power-on pop
noise prevention) NAB time constant circuit in the same way
when regulating the gain at recording stage. The operating
point of the output stage (1,7pin) is fixed at 3VF.
Accordingly, even if VCC is raised to 5V or more, as in the
VMAX-VCC characteristic (Fig.13), the maxim um output voltage
does not rise above 1.2V (Typ.). 4pin is gr ounded at playback
since ALC is not needed. For better signal-to-noise ratio
characteristics at playback, don’t use R1 and R2, which are
attached to the input pin (13pin, 9pin).
Fig.7
A1 BA3308
2 (8)
10μF
0.027μF
39
1 (9) 3 (7) 5
INPUT OUTPUT
R3
(R4)
C9
(C10)
(C6)
C5
10μF
(C2)
C1
100μF
(C4)
C3
R11
(R12)
4.3k
R9
(R10)
120k
13(9) 11(10) 1 (7) 4
Fig.16
Technical Note
7/9
BA3308F,BA3308FV
www.rohm.com 2012.06 - Rev.C
© 2011 ROHM Co., Ltd. All rights reserved.
●Measurement circui t
●Applic at ion c ircuit
Fig.18
For playback, connect the following NAB time constant circuit between
pins 11 and 1 and pins 10 and 7 in place of R5 and R6.
INPUT1
INPUT2
1
2
3
4
5
6
78
9
10
11
12
13
14
ALC
10F
100F
100F
39
10F
330F
220
22F
VCC=7
3.9k
3.9k
10F
10F
R4
C4
R6
18k
C6
OUTPUT2
R8
1M
R7
C7
C8
18k
R5
C5
OUTPUT1
39
R3
R1
R2
C3
C2
C5
C9 (C10)
0.027F
R9 (R10)
120k
R11 (R12)
4.3k
Fig.17
1
2
3
4
5
6
7
8
9
10
11
12
13
14
ALC
V
V
V
V V V
10k
10F 120k
1.2k 33k
0.1F
SW4A
100F
SW2A V2
22k 2
1 3 SW6A
30k INPUT1
SW3A
3.9k
3.9k SW3B
30k INPUT2
SW6B
SW1B
3
2
1
V2 2.2k
SW2B
100F
39
SW4B
2
1
0.1F
1.2k
120k
10F
10k
330F
220
SW5 22F
1M
VCC
OUTPUT1
OUTPUT2
2
1
33k
V1
V1
39
Fig.17
Technical Note
8/9
BA3308F,BA3308FV
www.rohm.com 2012.06 - Rev.C
© 2011 ROHM Co., Ltd. All rights reserved.
●Notes for use
1) Numbers and data in entries are representative design values and are not guaranteed val ues of the items.
2) Although ROHM is confident that the example application circuit reflects the best possible recommendations, be sure
to verify circuit characteristics for your particular application. Modification of constants for other externally connected
circuits may cause variations in both static and transient characteristics for external components as well as this Rohm
IC. Allow for sufficient margins when determining circuit constants.
3) Absolute maximum ratings
Use of the IC in excess of absolute maximum ratings, such as the applied voltage or oper ating temperature range
(Topr), may result in IC damage. Assumptions should not be made regarding the state of the IC (short mode or open
mode) when such damage is suffered. A physical safety measure, such as a fuse, should be implemented when using
the IC at times where the absolute maximum ratings ma y be exceeded.
4) GND potential
Ensure a minimum GND pin potential in a ll operating conditions. Make sure that no pins are at a voltage below the
GND at any time, regardless of whether it is a transient signal or not.
5) Thermal design
Perform thermal design, in which there are adequate margins, by taking into account the permissible dissipation (Pd) in
actual states of use.
6) Short circuit betw een terminals and erroneous mounting
Pay attention to the asse mbly direction of the ICs. W rong moun ting direction o r short s betw een terminals, GND, or o ther
components on the circui ts, can damage the IC.
7) Operation in strong magnetic fields
Using the ICs in a strong electromagnetic field can cause operation malfunction.
8) The BA3308F/FV has an on-chip power supply mute circuit that checks for pop noise at power-on. This prevents the
occurrence of pop noise by timing the charge times of the direct current cut capacitors C3 and C4 of 10pin and 11pin,
and of capacitor C8 for the ripple filter of 5pin.
Accordingly, to obtain an adequate effect, it is recommended that the constants of the application circuit be used in C3,
C4, R3, R4, C8, and R8.
Technical Note
9/9
BA3308F,BA3308FV
www.rohm.com 2012.06 - Rev.C
© 2011 ROHM Co., Ltd. All rights reserved.
●Ordering part number
B A 3 3 0 8 F - E 2
Part No. Part No.
Package
F: SOP14
FV: SSOP-B14
Packaging and forming specific ation
E2: Embossed tape and reel
(Unit : mm)
SOP14
7
14
1.27
0.11
1
8
0.3MIN
8.7±0.2
0.4±0.1
0.15±0.1
1.5±0.1
6.2±0.3
4.4±0.2
(MAX 9.05 include BURR)
0.1
∗
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
∗
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)
SSOP-B14
8
7
14
1
0.10
6.4 ± 0.3
4.4
±
0.2
5.0 ± 0.2
0.22 ± 0.1
1.15 ± 0.1
0.65
0.15 ± 0.1
0.3Min.
0.1
Datasheet
Datasheet
Notice - GE Rev.002
© 2014 ROHM Co., Ltd. All rights reserved.
Notice
Precaution on using ROHM Products
1. Our Products are designed and manufactured for application in ordinary electronic equipments (such as AV equipment,
OA equipment, telecommunication equipment, home electronic appliances, amusement equipment, etc.). If you
intend to use our Products in devices requiring extremely high reliability (such as medical equipment (Note 1), transport
equipment, traffic equipment, aircraft/spacecraft, nuclear power controllers, fuel controllers, car equipment including car
accessories, safety devices, etc.) and whose malfunction or failure may cause loss of human life, bodily injury or
serious damage to property (“Specific Applications”), please consult with the ROHM sales representative in advance.
Unless otherwise agreed in writing by ROHM in advance, ROHM shall not be in any way responsible or liable for any
damages, expenses or losses incurred by you or third parties arising from the use of any ROHM’s Products for Specific
Applications.
(Note1) Medical Equipment Classification of the Specific Applications
JAPAN USA EU CHINA
CLASSⅢ CLASSⅢ CLASSⅡb CLASSⅢ
CLASSⅣ CLASSⅢ
2. ROHM designs and manufactures its Products subject to strict quality control system. However, semiconductor
products can fail or malfunction at a certain rate. Please be sure to implement, at your own responsibilities, adequate
safety measures including but not limited to fail-safe design against the physical injury, damage to any property, which
a failure or malfunction of our Products may cause. The following are examples of safety measures:
[a] Installation of protection circuits or other protective devices to improve system safety
[b] Installation of redundant circuits to reduce the impact of single or multiple circuit failure
3. Our Products are designed and manufactured for use under standard conditions and not under any special or
extraordinary environments or conditions, as exemplified below. Accordingly, ROHM shall not be in any way
responsible or liable for any damages, expenses or losses arising from the use of any ROHM’s Products under any
special or extraordinary environments or conditions. If you intend to use our Products under any special or
extraordinary environments or conditions (as exemplified below), your independent verification and confirmation of
product performance, reliability, etc, prior to use, must be necessary:
[a] Use of our Products in any types of liquid, including water, oils, chemicals, and organic solvents
[b] Use of our Products outdoors or in places where the Products are exposed to direct sunlight or dust
[c] Use of our Products in places where the Products are exposed to sea wind or corrosive gases, including Cl2,
H2S, NH3, SO2, and NO2
[d] Use of our Products in places where the Products are exposed to static electricity or electromagnetic waves
[e] Use of our Products in proximity to heat-producing components, plastic cords, or other flammable items
[f] Sealing or coating our Products with resin or other coating materials
[g] Use of our Products without cleaning residue of flux (even if you use no-clean type fluxes, cleaning residue of
flux is recommended); or Washing our Products by using water or water-soluble cleaning agents for cleaning
residue after soldering
[h] Use of the Products in places subject to dew condensation
4. The Products are not subject to radiation-proof design.
5. Please verify and confirm characteristics of the final or mounted products in using the Products.
6. In particular, if a transient load (a large amount of load applied in a short period of time, such as pulse. is applied,
confirmation of performance characteristics after on-board mounting is strongly recommended. Avoid applying power
exceeding normal rated power; exceeding the power rating under steady-state loading condition may negatively affect
product performance and reliability.
7. De-rate Power Dissipation (Pd) depending on Ambient temperature (Ta). When used in sealed area, confirm the actual
ambient temperature.
8. Confirm that operation temperature is within the specified range described in the product specification.
9. ROHM shall not be in any way responsible or liable for failure induced under deviant condition from what is defined in
this document.
Precaution for Mounting / Circuit board design
1. When a highly active halogenous (chlorine, bromine, etc.) flux is used, the residue of flux may negatively affect product
performance and reliability.
2. In principle, the reflow soldering method must be used; if flow soldering method is preferred, please consult with the
ROHM representative in advance.
For details, please refer to ROHM Mounting specification
Datasheet
Datasheet
Notice - GE Rev.002
© 2014 ROHM Co., Ltd. All rights reserved.
Precautions Regarding Application Examples and External Circuits
1. If change is made to the constant of an external circuit, please allow a sufficient margin considering variations of the
characteristics of the Products and external components, including transient characteristics, as well as static
characteristics.
2. You agree that application notes, reference designs, and associated data and information contained in this document
are presented only as guidance for Products use. Therefore, in case you use such information, you are solely
responsible for it and you must exercise your own independent verification and judgment in the use of such information
contained in this document. ROHM shall not be in any way responsible or liable for any damages, expenses or losses
incurred by you or third parties arising from the use of such information.
Precaution for Electrostatic
This Product is electrostatic sensitive product, which may be damaged due to electrostatic discharge. Please take proper
caution in your manufacturing process and storage so that voltage exceeding the Products maximum rating will not be
applied to Products. Please take special care under dry condition (e.g. Grounding of human body / equipment / solder iron,
isolation from charged objects, setting of Ionizer, friction prevention and temperature / humidity control).
Precaution for Storage / Transportation
1. Product performance and soldered connections may deteriorate if the Products are stored in the places where:
[a] the Products are exposed to sea winds or corrosive gases, including Cl2, H2S, NH3, SO2, and NO2
[b] the temperature or humidity exceeds those recommended by ROHM
[c] the Products are exposed to direct sunshine or condensation
[d] the Products are exposed to high Electrostatic
2. Even under ROHM recommended storage condition, solderability of products out of recommended storage time period
may be degraded. It is strongly recommended to confirm solderability before using Products of which storage time is
exceeding the recommended storage time period.
3. Store / transport cartons in the correct direction, which is indicated on a carton with a symbol. Otherwise bent leads
may occur due to excessive stress applied when dropping of a carton.
4. Use Products within the specified time after opening a humidity barrier bag. Baking is required before using Products of
which storage time is exceeding the recommended storage time period.
Precaution for Product Label
QR code printed on ROHM Products label is for ROHM’s internal use only.
Precaution for Disposition
When disposing Products please dispose them properly using an authorized industry waste company.
Precaution for Foreign Exchange and Foreign Trade act
Since our Products might fall under controlled goods prescribed by the applicable foreign exchange and foreign trade act,
please consult with ROHM representative in case of export.
Precaution Regarding Intellectual Property Rights
1. All information and data including but not limited to application example contained in this document is for reference
only. ROHM does not warrant that foregoing information or data will not infringe any intellectual property rights or any
other rights of any third party regarding such information or data. ROHM shall not be in any way responsible or liable
for infringement of any intellectual property rights or other damages arising from use of such information or data.:
2. No license, expressly or implied, is granted hereby under any intellectual property rights or other rights of ROHM or any
third parties with respect to the information contained in this document.
Other Precaution
1. This document may not be reprinted or reproduced, in whole or in part, without prior written consent of ROHM.
2. The Products may not be disassembled, converted, modified, reproduced or otherwise changed without prior written
consent of ROHM.
3. In no event shall you use in any way whatsoever the Products and the related technical information contained in the
Products or this document for any military purposes, including but not limited to, the development of mass-destruction
weapons.
4. The proper names of companies or products described in this document are trademarks or registered trademarks of
ROHM, its affiliated companies or third parties.
DatasheetDatasheet
Notice – WE Rev.001
© 2014 ROHM Co., Ltd. All rights reserved.
General Precaution
1. Before you use our Pro ducts, you are requested to care fully read this document and fully understand its contents.
ROHM shall n ot be in an y way responsible or liabl e for fa ilure, malfunction or acci dent arising from the use of a ny
ROHM’s Products against warning, caution or note contained in this document.
2. All information contained in this docume nt is current as of the issuing date and subj ect to change without any prior
notice. Before purchasing or using ROHM’s Products, please confirm the la test information with a ROHM sale s
representative.
3. The information contained in this doc ument is provi ded on an “as is” basis and ROHM does not warrant that all
information contained in this document is accurate an d/or error-free. ROHM shall not be in an y way responsible or
liable for any damages, expenses or losses incurred b y you or third parties resulting from inaccuracy or errors of or
concerning such information.
