SANYO LA1231

Ordering number : EN660A
Monolithic Linear IC
LA1231N
FM IF System
Overview
Package Dimensions
Being developed for FM IF System, LA1231 is a highly unit: mm
integrated circuit in which almost all functions are
3006B-DIP16
contained concerning the FM tuner IF stage. The block
diagram of equivalent circuit is shown below. Usual
peripheral circuits are shown also in examples of
application circuits.
The IF amplifier and limiter stages are composed of 6stage double-end type differential amplifier, which is
superior on its AMR. The signal meter driving stage which
is located in parallel therewith consists of a 3-stage level
detector circuit and a drive circuit in order to extend the
linear area.
The FM detection stage composed of a double-balance type
[LA1231N]
SANYO: DIP16
quadrature detecting circuit is attached with a low frequency preamplifier and muting control circuit.
The muting drive stage is composed of the following 3 circuits.
1) A level detection circuit which detects the S/N ratio of carrier wave when the input is weak.
2) A circuit which detects the dc output of FM detector's 'S' curve when detuning is made.
3) A driving circuit.
Thus, this muting driving stage can reduce foreign factors such as the interstation noises, the shock noise caused from
muting when detuning is made, and so forth.
Besides, a voltage-inverting circuit is built in LA1231N so that the muting may be enabled at any appropriate input signal
level. The output of this voltage-inverting circuit is connected with the muting drive output terminal. Thus, the muting can
be placed to the ON or OFF status when a control voltage is applied from other section to the input terminal of the voltageinverting circuit. For the control voltage, the output of the signal meter driver is appropriate. Both the AFC output stage
and tuning meter driving stage are of the current-driven type. So, not only the sensitivity of AGC but also the muting band
(when detuning is made) can be controlled by an outer resistor.
Being utilized for disabling the FM IF amplifier when AM reception is made, the IF amplification/stop circuit can decrease
the shock noise caused at the conversion between FM and AM reception modes.
Functions
• IF amplification, Limiter.
• AF preamplifier.
• Muting at the detuning.
• AFC tuning meter drive output.
• Inverting circuit for muting drive voltage.
• Quadrature detection.
• Muting at weak.
• Signal meter drive output.
• Delay AGC output.
• IF amplifier stop circuit.
SANYO Electric Co.,Ltd. Semiconductor Bussiness Headquarters
TOKYO OFFICE Tokyo Bldg., 1-10, 1 Chome, Ueno, Taito-ku, TOKYO, 110 JAPAN
O2097HA (KT)/8044/D040KI No.660-1/8
LA1231N
Features
• High sensitivity on limiting : 18µV typ.
• Low distortion : 0.05% typ. determined by the linearity of phase characteristics in phase shifting circuit.
• High demodulation output : 330 mVrms typ.
• High S/N ratio : 78.5dB typ.
• Muting at detuning with little shock noise.
• Single meter drive output proportional with the input signal level dB.
• Detuning muting band having good symmetrics.
• Tuning meter driving output having wide swing width.
• Delay AGC drive output for front end.
• Constant voltage circuit is built-in : operation voltage=9 to 14V.
• Muting characteristics between adjacent stations are distinguished.
Equivalent Circuit Block Diagram
Voltage regulator
Guadrature
limiter
IF amp/limiter
AFC/tuning
meter drive
Guadrature
det
AF amp
Level
det
Level
det
IF amp
stop
Level
det
Signal meter
drive
Level
det
Level
det
DC
level
Mute
control
Mute drive
Specifications
Maximum Ratings at Ta=25°C
Parameter
Symbol
Conditions
VCCmax
Pin 11
Maximum input voltage
VIN
Maximum supply current
ICC
Maximum supply voltage
Maximum flow-in current
Maximum flow-out current
Ratings
Unit
16
V
Pins 1-2
±1
Vp-p
Pin 11
40
mA
I15
Pin 15
1
mA
I16
Pin 16
1
mA
I10
Pin 10
2
mA
I12
Pin 12
2
mA
I13
Pin 13
2
mA
I15
Pin 15
2
mA
Allowable power dissipation
Pd max
650
mA
Operating temperature
Topr
–20 to +70
°C
Storage temperature
Tstg
–40 to +125
°C
No.660-2/8
LA1231N
Recommended Operating Conditions at Ta=25°C
Parameter
Supply voltage
Symbol
Conditions
Ratings
Unit
12
VCC
V
Operating Characteristics at Ta=25°C, VCC=12V, f=10.7MHz
Parameter
Quiescent current
Symbol
Conditions
Ratings
min
ICCO
max
22
30
mA
33
mA
Current drain
ICC
VIN=100dBµ
Demodulated output
Vo
VIN=100dBµ, 400Hz-100% mod
240
330
VIN=100dBµ, 400Hz-100% mod
72
78.5
VIN(lim)
Vo 3dB down, 400Hz-100% mod
S/N
Input limiting voltage
Unit
typ
26.5
460 mVrms
dB
25
31
dBµ
Total harmonic distortion
THD
VIN=100dBµ, 400Hz-100% mod
0.05
0.3
%
Muting sensitivity
VIN(mute)
V12=1.4V
23
29
35
dBµ
Muting attenuation
Mute(att)
V5=2V, VIN=100dBµ,
60
65
140
220
45
60
4.0
4.9
6.0
V
dB
400Hz-100% mod
Muting bandwidth
BW(mute) VIN=100dBµ, V12=1.4V
AM rejection ratio
AMR
VIN=100dBµ, FM : 400Hz-100% mod
370
kHz
Muting driving output
V12
Quiescent
VIN=100dBµ
0
0
0.3
V
Signal meter driving output
V13
Quiescent
0
0
0.1
V
4.2
dB
AM : 1kHz-30% mod
AGC output
V15
VIN=70dBµ
1.9
3.0
VIN=100dBµ
4.5
5.5
Quiescent
4.2
5.0
5.5
V
0
0
0.5
V
VIN=100dBµ
V
V
IF off current
I15(off)
Quiescent, V8-10≤20mV
10
35
60
µA
Voltage of muting operation
V16(mute) VIN=100dBµ, V12=1.4V
0.7
0.84
1.0
V
Offset voltage
V6-10 B
Quiescent, pin 6-10
V7-10 B
Quiescent, pin 7-10, R7-10=5.1kΩ
V1
Quiescent
2.6
V
V2
Quiescent
2.6
V
V3
Quiescent
2.6
V
V6
Quiescent
5.6
V
V7
Quiescent
5.6
V
V8
Quiescent
5.4
V
V10
Quiescent
5.6
V
V12
Quiescent
4.9
V
V13
Quiescent
0
V
V15
Quiescent
5.0
V
Pin voltage
–0.5
0
+0.5
V
–0.25
0
+0.25
V
No.660-3/8
LA1231N
Test Circuit
Allowable power dissipation, Pd max – mW
Pd max – Ta
Ambient temperature, Ta – °C
Unit (resistance : Ω, capacitance : F)
DC characteristics
AC characteristics
Unit (resistance : Ω, capacitance : F)
No.660-4/8
An Example of Printed Pattern Board (70×95mm2, bottom view)
Front end
IF amp
stop
Level
det
Level
det
Signal meter
Mute drive
Level
det
DC
level
Guadrature
det
Muting switch
Mute
control
AF amp
AFC/tuning
meter drive
Unit (resistance : Ω, capacitance : F)
Level
det
Guadrature
limiter
Mute on
level adj.
Signal meter
drive
Level
det
IF amp/limiter
Voltage regulator
AF output
Tuning meter
Det transformer
SNY-074-1700 (Sumida's) or
MV4FCC-20826EP (Toko's)
LA1231N
Sample Application Circuit
No.660-5/8
LA1231N
Pin voltage, V12, V13, V15 – V
Demodulated output, VO
Distortion, THD AM rejection ratio, AMR
Output noise voltage, VNO – dB
Pin Voltage – VIN
IF input voltage, VIN – dBµ
IF input voltage, VIN – dBµ
V12 – ∆f
Pin voltage, V12 – V
Pin voltage, V7-10 – V
V7-10 – ∆f
Detuning frequency, ∆f – kHz
Detuning frequency, ∆f – kHz
Pin voltage, V12 – V
Muting attenuation, Mute(att) – dB
Mute(att) – V5
Quadrature signal, V9 – mVrms
Pin voltage, V12 – V
Pin voltage, V16 – V
Pin voltage, V5 – V
Unit (resistance : Ω, capacitance : µF)
Pin voltage, V16 – V
Resistance between pin and ground, R16-G – Ω
No.660-6/8
Pin voltage, V13 – V
Pin voltage, V10, V12 – V
Current drain, ICC – mA
Demodulated output, VO – mVrms
Muting sensitivity, VIN(mute) – dBµ
Input limiting voltage, VIN(lim) – dBµ
Limiting voltage, VIN(lim) – dBµ
Ambient temperature, Ta – °C
Muting bandwidth, BW(mute) – kHz
Pin voltage, V15(IF off) – V
IF amp stop current, I15(IF off) – A
LA1231N
I15(IF off) – VIN
IF input voltage, VIN – dBµ
VIN(lim) – Rg
Resistance between pin7-10 – kΩ
VIN(mute), VIN(lim) – Ta
Generator resistance, Rg – Ω
Ambient temperature, Ta – °C
Ambient temperature, Ta – °C
Ambient temperature, Ta – °C
Ambient temperature, Ta – °C
No.660-7/8
Pin voltage, V15 – V
Muting attenuation, Mute(att) – dB
LA1231N
Ambient temperature, Ta – °C
Current drain, ICC – mA
Muting bandwidth, BW(mute) – kHz
Ambient temperature, Ta – °C
Supply voltage, VCC – V
Detuning – kHz
Ambient temperature, Ta – °C
Supply voltage, VCC – V
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 guaranteed 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 October, 1997. Specifications and information herein are subject
to change without notice.
No.660-8/8