LA1193M_08 SANYO [Sanyo Semicon Device], LA1193M_08 Datasheet - Page 10

• Manufacturer Part Number: LA1193M_08
• Description: High-Performance FM Front End
• Manufacturer: SANYO [Sanyo Semicon Device]

3D-AGC Features
Features of the Double Wide AGC System
— Since this is a mixer input detection wide-band AGC, it prevents the occurrence of intermodulation due to
— Since this system uses a narrow AGC at the same time, the wide AGC sensitivity can be lowered, thus preventing
— Optimal sensitivities for any field conditions can be set, since the sensitivities of both the wide and narrow AGC
— The input level of the desired station is limited by the narrow AGC. As a result, excessive levels are no longer input
• Two-Signal Sensitivity Suppression Characteristics
Previously, keyed AGC systems were used to provide good intermodulation distortion and two signal sensitivity
suppression characteristics at the same time. However, in previous keyed AGC systems, when the desired station
would fade or drop out, the wide band AGC level would become essentially zero. As a result, the automatic station
selection function would malfunction and blocking oscillation would occur in the presence of strong interfering
stations. Thus keyed AGC systems were extremely hard to use in actual practice. Sanyo has developed a new AGC
system (3D-AGC) that solves these problems and allows the construction of extremely simple application circuits.
The LA1193M/V incorporates this AGC system.
What is the 3D-AGC system?
It is a system that determines the wide-band AGC level by using information that has the following three frequency
characteristics.
The narrow AGC sensitivity, which operates for ∆f of less than 1.5MHz, is
controlled independently according to the field strength of the desired
station.
The narrow AGC sensitivity is controlled at V 20 values under 2V.
The wide AGC operates even when V 20 is zero, i.e., when the desired
station does not exist.
The N-AGC and the W-AGC sensitivities can be set independently.
The system has two AGC systems, the N-AGC and the W-AGC.
interfering stations with ∆f > 1MHz. (TV band interference prevention)
incorrect operation due to local oscillator injection.
systems can be set by changing the values of external components.
to the stages that follow the mixer and the beats at multiples of 10.7 × A are reduced.
RF and antenna circuit information
Mixer circuit information
C, F and selectivity information
Feature
LA1193M, 1193V
Mixer input AGC
Mixer output AGC
S-meter output
• This is effective as a measure for mitigating two signal sensitivity
• This allows two signal sensitivity suppression to be mitigated without
• This allows the prevention of incorrect stopping on intermodulation
• This allows the prevention of intermodulation occurring in the
• This allows optimal settings to match the reception field conditions.
• Since the narrow AGC operates at the desired station and at
suppression.
deterioration in the three signal characteristics.
signals during search.
antenna and RF modulation circuits in the presence of strong
interfering stations. Prevention of blocking oscillation due to AGC
operation is also possible.
adjacent stations, it is possible to reduce the wide AGC sensitivity.
This prevents incorrect AGC operation due to local oscillator
injection.
Three
dimensions
Merit
No.4715-10/22