Rohm BA3835F Silicon monolithic integrated circuit Datasheet

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Structure :
Silicon Monolithic Integrated Circuit
Product :
Band-pass filter for spectrum analyzer for car audio systems
Type ::
BA3835F
Function
:
1. Built-in band pass filter for spectrum analyzer. BA3835F is for 5 bands.
2. Designed for 5V microcomputer power voltage.
Absolute Maximum Ratings (Ta=25℃)
Symbol
Rating
Parameter
Power Supply voltage
Vcc
7
Power dissipation
Pd
450※
Operating temperature
Topr
-25~+75
Storage temperature
Tstg
-55~+125
※This value decreases 4.5 mW/℃ for Ta=25℃ or more.
Operating Voltage Range(Ta=25℃)
Parameter
Symbol
Vcc
Power supply voltage
Min.
4.5
Typ.
5.0
Unit
V
mW
℃
℃
Max.
6.5
Unit
V
Electrical Characteristics
(Unless specified particularly, Ta=25℃,VCC=5V,RL=10MΩ,VAIN=-30dBV,SEL=1)
Limit
Symbol
Parameter
Unit
Conditions
Min.
Typ.
Max.
VAIN=0V,A,B,C,SEL=0
Circuit current
ICC
-
8.5
13
mA
Maximum output level
VOM
4.0
4.8
-
V
Output offset voltage
VOS
-
30
150
mV
Standard output level 1
VO1
0.65
1.35
1.70
V
VAIN=-14dBV,,Measured at each output
VAIN=0V,SEL=0/1, Measured at
each output (cycle time:Ts=50ms)
fIN=105Hz,A=0,B=0,C=1
Standard output level 2
VO2
0.65
1.35
1.70
V
fIN=340Hz,A=0,B=1,C=0
Standard output level 3
VO3
0.65
1.35
1.70
V
fIN=1kHz,A=1,B=0,C=0
Standard output level 4
VO4
0.65
1.35
1.70
V
fIN=3.4kHz,A=1,B=1,C=0
Standard output level 5
VO5
0.65
1.35
1.70
V
fIN=10.5kHz,A=1,B=1,C=1
Application example
Note that ROHM cannot provide adequate confirmation of patents.
The product described in this specification is designed to be used with ordinary electronic equipment or devices (such as audio-visual
equipment, office-automation equipment, communications devices, electrical appliances, and electronic toys).
Should you intend to use this product with equipment or devices which require an extremely high level of reliability and the malfunction of which
would directly endanger human life (such as medical instruments, transportation equipment, aerospace machinery, nuclear-reactor controllers, fuel
controllers and other safety devices), please be sure to consult with our sales representative in advance.
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Parameter
Symbol
Limit
Min.
Typ.
Max.
Unit
Conditions
RIN
80
100
120
kΩ
fIN=1kHz
CMRR
25
50
-
dB
fIN=1kHz,VAIN=VCIN
Logic input high level
VIH
2.5
5.0
-
V
Logic input low level
VIL
-
0
0.5
V
Output response time*1
TO
-
5
10
μsec
-
Not applicable in the whan item 10 of
operation notes applies.
-
Discharge level
DL
-
3
-
dB
Reset pulse width TR=10μsecTyp.*2
Input impedance
Common-mode rejection ratio
*1 The time from the rise of A, B, C or SEL until the rise of AOUT (90% of peak). If the output selection time is less than this, the output voltage is not
guaranteed and the reset pulse is not generated.
*2 Automatically generated internally based on the output select signal. For the duration that this signal is “H”, a resister is connected to the peak hold
capacitor, and the output level drops by –3dB (typ.) for one pulse.
*3 The Q of the bandpass filter is 3.5
◎ Not designed for radiation resistance.
Output select logic table
SEL
0
1
1
1
1
1
1
1
1
A
×
0
0
0
0
1
1
1
1
B
×
0
0
1
1
0
0
1
1
C
×
0
1
0
1
0
1
0
1
×: Don't Care.
Timing chart
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AOUT
GND
GND
105Hz
340Hz
GND
1kHz
GND
3.4kHz
10.5kHz
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Block Diagram
BIASC
GND
BI A S
1
1 8
AOUT
VREFC
2
V R E F
1 7
TEST
RREF
RE F F E R E N C E C U R R E N T
3
1 6
N.C
N.C
1 5
4
105Hz
BPF
PEAK
HOLD
DIFOUT
5
SEL
RES
A-C
340Hz
BPF
1 4
PEAK
HOLD
RES
N.C.
1kH
z
BPF
6
PEAK
HOLD
N.C
MPX
1 3
7
C
DIF
3.4kH
z
BPF
Terminal
Number
Terminal
Name
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
BIASC
VREFC
RREF
N.C
DIFOUT
N.C
CIN
AIN
VCC
A
B
C
N.C
SEL
N.C
TEST
AOUT
GND
Outline Dimension
RES
CIN
Terminal Number/ Terminal Name
C
PEAK
HOLD
1 2
RES
10.5 k H z
BPF
AI N
8
A
BA3835F
PEAK
HOLD
B
1 1
RES
LOT No.
VCC
9
A
1 0
DEC
SOP18 (Unit:mm)
Application example
(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.
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(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) Frequency characteristics
The frequency characteristics of this IC are determined
by the resistor connected between the RREF terminal
and GND. For the specification conditions, the value of
this resistor is 100kΩ. If it is necessary to set the
frequency characteristics accurately, use a variable
resistor
(note: all bands will shift together).
(9) Load characteristics
To convert the bias sense output signal to the GND
sense signal, the IC performs a V / I conversion, and
then an I /V conversion using a 10kΩresistor (Typ.) for
the output. Therefore, if the load circuit connected to
the AOUT pin has a MOS structure there is no problem
(eg. Microprocessor input port), but if the connected
circuit has a low input impedance, it may cause the
output level to drop.
(10) External resistor for the control pin
When using a common port for the output select
control and FL drive, you must add a diode and resistor
as shown in the right figure to prevent the FL drive “L”
voltage from destroying the IC.
BA3835F
Provided that the IC is operated within the
recommended
operating
conditions
and
the
recommended temperature range, the basic circuit
functions are guaranteed. Within these ranges, ratings
for electrical characteristics for conditions other than
those stipulated cannot be guaranteed, but the inherent
function of the band pass filter will be maintained.
(12) Output offset voltage
The relationship between the output offset voltage and
the output selection cycle (cycle time) for this IC is
shown in Fig.5. The maximum output offset voltage of
150mV that is given in the electrical characteristics
table is under the condition that Ts = 200ms.
When Ts is greater than 50ms, the graph of the output
offset voltage is a straight line at 150mV. When Ts is
below 50ms, due to transient
characteristics of the peak hold circuit, the graph is a
line sloping downwards to the right. In other words, the
shorter
the cycle, the larger the output offset voltage.
Furthermore, the output offset voltage may shift due to
soldering or other temperature stresses from the
surroundings. Therefore, when setting the spectral
analyzer light level, take into consideration the points
given above
and make sure that it does not light by mistake during
quiescent periods. Use the chart below as a guide for
this, and, if necessary, leave even a larger margin.
In this case, the “L” voltage applied to the internal
comparator input terminal V1 is given by:
R1 +R
V1 =
× Vref
R1+R2+R
To maintain a noise margin of at least 2.5V with
respect to the comparator threshold level VREF, the
representative values for VREF, R1 and R2 are 1.5V,
20kΩ, and 10kΩrespectively. This gives:
20kΩ+R
× 1.5V+0.25V < 1.5V
20kΩ+20kΩ+R
And from this, the following condition is obtained:
R<30kΩ
In this case, the “L” level voltage V2 for the IC will be:
V2<0.75V
(11) Recommended operating ranges
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Notice
Notes
No copying or reproduction of this document, in part or in whole, is permitted without the
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
other parties. ROHM shall bear no responsibility whatsoever for any dispute arising from the
use of such technical information.
The Products specified in this document are intended to be used with general-use electronic
equipment or devices (such as audio visual equipment, office-automation equipment, communication devices, electronic appliances and amusement devices).
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
against the possibility of physical injury, fire or any other damage caused in the event of the
failure of any Product, such as derating, redundancy, fire control and fail-safe designs. ROHM
shall bear no responsibility whatsoever for your use of any Product outside of the prescribed
scope or not in accordance with the instruction manual.
The Products are not designed or manufactured to be used with any equipment, device or
system which requires an extremely high level of reliability the failure or malfunction of which
may result in a direct threat to human life or create a risk of human injury (such as a medical
instrument, transportation equipment, aerospace machinery, nuclear-reactor controller, fuelcontroller or other safety device). ROHM shall bear no responsibility in any way for use of any
of the Products for the above special purposes. If a Product is intended to be used for any
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R1120A
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