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Электронный компонент: LA1065M

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LA1065M
Ordering number : EN3312
2 Tuner Diversity Circuit
for Car FM Tuner
Monolithic Linear IC
SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN
93097HA (KT)/2200TA, TS (AF) No.3312-1/8
Overview
The LA1065M is a multi-functional IC for 2 tuner
diversity, and is capable of multi-path distortion detection
with high sensitivity.
Functions
Noise amplifier.
Noise AGC circuit.
Noise density comparison counting circuit.
MAIN/SUB switching output.
Weak electric field detection and antenna fixing circuit.
Very strong electric field detection and antenna fixing
circuit.
S meter voltage comparison circuit.
Package Dimensions
unit: mm
3036B-MFP20
[LA1065M]
SANYO: MFP20
AGC voltage output.
S meter switch.
Specifications
Maximum Ratings
at Ta=25C
Parameter
Symbol
Conditions
Ratings
Unit
Maximum supply voltage
VCC max
13
V
Maximum flow-out current
I(4)
Pin 4
1
mA
I(5)
Pin 5
1
mA
I(6)
Pin 6
1
mA
I(9)
Pin 9
10
mA
I(12)
Pin 12
100
A
Maximum flow-in current
I(7)
Pin 7
1
mA
I(8)
Pin 8
1
mA
Maximum applied voltage
V(15)
VCC
V
V(16)
VCC
V
V(17)
VCC
V
V(13)
VCC
V
V(14)
VCC
V
Allowable power dissipation
Pd max
Ta=25C
230
mW
Operating temperature
Topr
30 to +80
C
Storage temperature
Tstg
40 to +125
C
LA1065M
No.3312-2/8
Operating Conditions
at Ta=25C
Parameter
Symbol
Conditions
Ratings
Unit
Recommended supply voltage
VCC
8
V
Operating voltage range
VCC op
7 to 12
V
Operation Characteristics
at Ta=25C, VCC=8V, f=100kHz sine wave
Parameter
Symbol
Conditions
Ratings
min
typ
max
Unit
Current drain
ICC
No input, not including pin 9 current
10
16
22
mA
Pin 9 high-level voltage
V9H
1k
resistance between pin 9 and GND
5.0
6.0
7.5
V
Noise amplifier gain
Gsub
Vsub in=10mVrms pin 6 output
33
36
39
dB
Noise amplifier gain
GV1
Vmain in=Vsub in=1mVrms pin 6 output
33
36
39
dB
GV2
Vmain in=Vsub in=100mV pin 6 output
6
10
14
dB
Noise detection sensitivity
NDS
Noise AGC off
8
12
16
mVrms
Noise count number
NCN
Difference between MAIN and SUB noise
4
Gate time 1
tG
Noise AGC off
500
620
740
s
Repeat cycle of pin 4 waveform
Pin 6 voltage
V6
Vmain=Vsub=200mVrms
0.4
1.1
2.0
V
Pin 5 voltage
V5
Vsub=100mVrms
2.50
2.85
3.20
V
Strong field detection level
V17
0.7
1.1
1.5
V
Medium field detection level
V14
2.4
2.7
3.1
V
Weak field detection level
V13
1.7
2.1
2.4
V
S meter switch residual
V12
Input=0V
130
mVrms
Equivalent Circuit Block Diagram
LA1065M
No.3312-3/8
Sample Application Circuit
Unit (resistance :
, capacitance : F)
Operating Principle
(1) Multi-path distortion detection
Overview
The LA1065M compares the high frequency noise elements in the S meter output from the two tuners to perform
multi-path distortion detection.
In addition to the higher harmonic distortion due to multi-path, the S meter noise includes pulse noise such as car
engine ignition noise, distortion elements due to modulation, phase noise and so on. All of this noise causes
misoperation of multi-path distortion detection.
The LA1065M resolves this problem through use of a unique noise count comparison method and the bottom
detection-type noise AGC.
Noise count comparison
The causes of misoperation in a diversity reception system, which are pulse noise, distortion elements caused by
modulation, and phase noise, exist almost equally for MAIN and SUB. Also, the multi-path distortion to be
detected tends to exist on either the MAIN or SUB side.
The LA1065M uses an up/down counter to compare the noise counts of MAIN and SUB and detect multi-path.
Bottom detection noise AGC
As described above, the S meter noise also exists on both MAIN and SUB sides, so when there is noise on both
sides, AGC goes on to prevent misoperation. On the other hand, when multi-path is generated and noise is on one
side or the other, AGC does not go on, enabling high sensitivity detection.
A combination of the above methods is used to make the LA1065M capable of accurate multi-path detection.
LA1065M
No.3312-4/8
(2) S meter voltage comparison
For a medium field, the sound may be better if the antenna is switched by comparing S meter DC voltage rather
than using multi-path distortion detection when, for example, there is quite a difference (more than 10dB) in
antenna sensitivity between MAIN and SUB. On the LA1065M, a built-in comparator detects the medium field,
and compares S meter DC voltage in order to switch the antenna.
(3) Weak field detection and antenna fixing (MAIN)
There is a difference in antenna sensitivity between MAIN and SUB in a weak field, so sensitivity will be
insufficient even if switched to SUB.
The LA1065M uses a comparator, as shown below, to detect the weak field and fix the switching signal to the
MAIN side.
(4) Very strong field detection and antenna fixing (SUB)
Interference such as I.M. (intermodulation) and cross modulation is generated in a very strong field. One
countermeasure is to use a PIN diode for antenna damping, but here the lower antenna gain on the SUB side is
utilized to fix the antenna to the SUB side when the electric field is strong. Also, with LA1065M, operation
returns to normal when multi-path is generated.
(5) AGC voltage output
As described in the section on bottom detection-type noise AGC, AGC voltage goes high when there is a lot of
noise on both MAIN and SUB sides. This voltage can be used to apply SNC, HCC and so on when the conditions
are poor for both MAIN and SUB.
(6) S meter switch
The LA1065M has built-in S meter switch so that SNC can be applied according to the MAIN and SUB switching
output. When the antenna is on MAIN, SNC is applied by MAIN side S meter voltage, and when it is on SUB, by
SUB side meter voltage.
(7) Logic section
The LA1065M operation is shown in th table below.
Unit (resistance :
)
MAIN multi-
path detection
With noise
No noise
*
*
*
*
No noise
Large noise
Small noise
No noise
With noise
*
*
*
No noise
With noise
Medium noise
Medium noise
*
*
*
MAIN>SUB
MAIN<SUB
*
*
*
*
Strong field
Strong field
Weak field
Medium field
Medium field
Strong field
Strong field
Strong field
Strong field
Weak-medium field
Weak-medium field
*
Weak-medium field
Weak-medium field
Very strong field
Very strong field
Very strong field
Very strong field
SUB side
MAIN side
MAIN side
MAIN side
SUB side
SUB side
MAIN side
SUB side
MAIN side
SUB multi-
path detection
MAIN S meter
voltage
SUB S meter
voltage
FE AGC voltage
MAIN/SUB
switching output
* : Under any conditions
LA1065M
No.3312-5/8
Pin No.
Function
External
The AC component of 114kHz in IF, S meter
output is taken by the BPF and input to pin 1 (or
pin 20) by C coupling.
Notes
1
(20)
MAIN IN
SUB IN
Be advised that the
LA1065M input impedance
changes with input and can
go to a minimum of 10k
.
Pin Function
2
(19)
H.P.F.
Highpass filter
3
(18)
AGC
Increase this capacitor's
value if antenna switching
tends to misoperate.
4
Monostable
multi-vibrator
Continued on next page.
Unit (resistance :
, capacitance : F)
LA1065M
No.3312-6/8
Continued from preceding page.
Unit (resistance :
, capacitance : F)
Pin No.
Function
External
Notes
5
SUB noise
detection for
strong field
6
AGC voltage
output
DC voltage corresponding
to the LA1065M AGC can
be taken.
MAIN is high (6V typ when
resistance bet-ween pin 9
and GND is 1k
) and SUB
is low.
7
8
Multi-path
detection mode
switching
9
MAIN/SUB
switching
signal output
Continued on next page.
Pin No.
GND
VCC
Pin 7
Pin 8
Count method for strong
field (4 counts)
S meter comparison for
medium field
S meter 114kHz level
comparison for strong field
Count method for medium field
(8 counts)
Mode switching table
LA1065M
No.3312-7/8
Continued from preceding page.
Unit (resistance :
, capacitance : F)
Pin No.
Function
External
Notes
10
GND
11
VCC
12
S meter output
13
Comparator
for weak field
detection
14
Comparator
for medium
field detection
15
SUB S meter
input
16
MAIN S meter
input
17
F.E.
AGC input
S meter input must be
sufficiently integrated
before input.
Comparison level is set at
approximately 1V.
LA1065M
No.3312-8/8
No products described or contained herein are intended for use in surgical implants, life-support systems,
aerospace equipment, nuclear power control systems, vehicles, disaster/crime-prevention equipment and
the like, the failure of which may directly or indirectly cause injury, death or property lose.
Anyone purchasing any products described or contained herein for an above-mentioned use shall:
Accept full responsibility and indemnify and defend SANYO ELECTRIC CO., LTD., its affiliates,
subsidiaries and distributors and all their officers and employees, jointly and severally, against any
and all claims and litigation and all damages, cost and expenses associated with such use:
Not impose any responsibilty for any fault or negligence which may be cited in any such claim or
litigation on SANYO ELECTRIC CO., LTD., its affiliates, subsidiaries and distributors or any of
their officers and employees jointly or severally.
Information (including circuit diagrams and circuit parameters) herein is for example only; it is not guarant-
eed for volume production. SANYO believes information herein is accurate and reliable, but no guarantees
are made or implied regarding its use or any infringements of intellectual property rights or other rights of
third parties.
This catalog provides information as of September, 1997. Specifications and information herein are
subject to change without notice.