Video Accessory ICs
VCA for Video Signal
Level Adjustment
BA7655AF
No.11069EBT04
●Description
The BA7655AF is a VCA (Voltage Controlled Amplifier) IC that was developed for VCR, DVC, or other video signal level
adjustment. It has two built-in amplifier circuits in which the voltage gain can be varied from -6 dB to +6 dB by adjusting the
voltage of the control pin. Moreover, when the CTL pin voltage is set to 1 V or less, it is in power save mode, in which the
current is reduced and output is muted.
●Features
1) Broadband frequency characteristics
2) Wide dynamic range
3) Low power consumption
4) Can mute output
5) Voltage gain temperature drift is small
●Applications
For VCR, DVC, and other video signal level adjustment
●Absolute Maximum Ratings(Ta=25℃)
Parameter
Symbol
Ratings
Unit
VCCMAX.
8.0
V
Pd
350*1
mW
Operating temperature
Topr
-20 ~ +80
℃
Storage temperature
Tstg
-55 ~ +125
℃
Supply Voltage
Power dissipation
*1 Derating is done at 3.5mW/℃ above Ta=25℃. (When mounted on a 50mm×50mm PCB board.)
●Operating Range(Ta=25℃)
Parameter
Supply voltage
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Symbol
Ratings
Unit
VCC
4.5 ~ 5.5
V
1/6
2011.04 - Rev.B
Technical Note
BA7655AF
●Electrical characteristics
(Unless otherwise noted, Ta=25℃,Vcc=5.0V)
Limits
CTL
Parameter
Symbol
Unit
Voltage(V)
Min. Typ. Max.
One channel
ICC1
―
4.6
7.0
Both channels
ICC2
―
7.8
12.0
Maximum output voltage
VMax.
2.5
2.8
Frequency characteristics
Gf
-1.0
Minimum voltage gain
GVMin.
Maximum voltage gain
Conditions
mA
3.0
CTL voltage set to 1 V or less
if using only one channel
―
VP-P
5.0
f=1kHz, THD=1%
0.0
1.0
dB
3.0
f=13MHz / 1MHz,VIN=0.5 VP-P
-8.0
-6.0
-4.0
dB
2.0
f=1MHz
GVMax.
4.0
6.0
8.0
dB
5.0
f=1MHz
2HD
―
-4.0
―
dB
3.0
f=5.0MHz,VIN=1 VP-P
AD
―
1.0
―
%
3.0
f=1kHz,VIN=1 VP-P
VMUTE
―
―
100
mV
1.0
CTL voltage set to 1 V or less
Video S/N *
VS/N
―
-60
―
dB
3.0
Audio S/N *
AS/N
―
-60
―
dB
3.0
circuit current
Secondary harmonic distortion
Audio distortion
Muting output voltage
*Items having this mark are reference values.
◎This product is not designed for protection against radioactive rays.
●Block diagram
Vcc
IN2
CTL2
8
7
6
OUT2
5
VCA2
VCA1
1
2
3
4
IN1
CTL1
OUT1
GND
Fig.1
●Equivalent circuit
1, 7PIN
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2, 6PIN
2/6
3,5PIN
2011.04 - Rev.B
Technical Note
BA7655AF
●Descriptions of operations
A VCA is an amplifier in which voltage gain can be varied by a control voltage, and in the BA7655AF, the voltage gain can be
varied from -6 dB to +6 dB by regulating the CTL pin voltage between 2 V and 5 V (if Vcc=5 V) as shown in the figure to the
right. Moreover, it contains two circuits and when using only one circuit, setting the CTL pin voltage of the unused circuit to 1
V or less moves it to power save mode, in which the circuit current is reduced approximately 40% and the output is muted.
IN
OUT
VCA
Control voltage
Fig.3
CTL VOLTAGE (V)
Fig.2 Voltage gain vs. Control voltage
CTL Voltage
Status
2V ~ 5V
Variable gain
1V or less
Power save
●Application circuit
DC 2.2V
10µF 1(7)
40kΩ
+
3(5)
RL≧10kΩ
or direct conection to next strage
DC 3.0V
2(6)
CTLVoltage
Fig.4
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3/6
2011.04 - Rev.B
Technical Note
BA7655AF
●Reference data
Fig.5 Voltage gain vs frequency characteristics
Fig.6
Fig.7 Voltage gain vs temperature
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Fig.8
4/6
Maximum voltage gain vs temperature
Minimum voltage gain vs temperature
2011.04 - Rev.B
Technical Note
BA7655AF
●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.
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 evaluates use in a strong magnetic field, since there is a possibility of malfunction.
8) Be sure to use input by capacitor coupling.
It cannot be used by direct connection. Find the capacitance of the coupling capacitor from the lowest frequency needed
by the signal used according to the following expression. Use of 10 µF is recommended when inputting a video signal.
C≧1/(2πfR) Where f is the lowest frequency used and R is the 40 kΩ input resistance built-in in the IC
9) The maximum input signal is 1.4 Vpp for a sine wave (such as a chroma signal) and 1.0 Vpp for a video signal (such as a
Y or a composite signal).
10) The output drivability is on the order of 10 KΩ.
Moreover, the output DC potential is approximately 2.2 V.
possible if only the conditions are met.
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5/6
On the output side, direct connection to the next stage also is
2011.04 - Rev.B
Technical Note
BA7655AF
●Ordering part number
B
A
7
Part No.
6
5
5
A
F
Part No.
-
E
Package
F: SOP8
2
Packaging and forming specification
E2: Embossed tape and reel
SOP8
6
5
+6°
4° −4°
0.3MIN
7
4.4±0.2
6.2±0.3
8
1 2
3
0.9±0.15
5.0±0.2
(MAX 5.35 include BURR)
Tape
Embossed carrier tape
Quantity
2500pcs
Direction
of feed
E2
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
)
4
0.595
1.5±0.1
+0.1
0.17 -0.05
S
S
0.11
0.1
1.27
1pin
0.42±0.1
Reel
(Unit : mm)
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6/6
Direction of feed
∗ Order quantity needs to be multiple of the minimum quantity.
2011.04 - Rev.B
Notice
Notes
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consent of ROHM Co.,Ltd.
The content specified herein is subject to change for improvement without notice.
The content specified herein is for the purpose of introducing ROHM's products (hereinafter
"Products"). If you wish to use any such Product, please be sure to refer to the specifications,
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 specified 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 specified 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
implicitly, any license to use or exercise intellectual property or other rights held by ROHM and
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use of such technical information.
The Products specified in this document are intended to be used with general-use electronic
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The Products specified in this document are not designed to be radiation tolerant.
While ROHM always makes efforts to enhance the quality and reliability of its Products, a
Product may fail or malfunction for a variety of reasons.
Please be sure to implement in your equipment using the Products safety measures to guard
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R1120A