LA7578 Sanyo Semiconductor Corporation, LA7578 Datasheet
LA7578
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LA7578 Summary of contents
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... Overview The LA7578N is an intercarrier-type VIF + SIF IC that supports excellent sound quality and image quality. The pin assignment of the LA7578N is identical to that of the LA7577N, allowing the LA7577N to be used for split systems while the LA7578N is used for intercarrier systems. In addition, the LA7578N suppresses Nyquist buzz interference by using a PLL detection system with a buzz canceller in order to provide the best sound quality possible ...
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... Sync signal tip voltage V 21 920 kHz beat level Frequency characteristics Differential gain Differential phase Maxinum AFT voltage V Mininum AFT voltage V White noise threshold voltage V White noise clamp voltage V Black noise threshold voltage V Black noise clamp voltage V LA7578N Symbol Conditions V max ° max ...
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... Black noise threshold voltage V Black noise clamp voltage V AFT detection sensitivity SIF output signal voltage V O [SIF Block] FM detection output voltage [Mute defeat voltage] AFT defeat start voltage VD AV mute V FM mute V AFT defeat voltage VD LA7578N Conditions 58.75 MHz f = 58.75 MHz - ...
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... Sample Application Circuit (JAPAN) LA7578N Unit (resistance : Pins 22 and 23 are grounded inside the IC. , capacitance: F) No.4037-4/18 ...
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... When using no SIF, 1stSIF, AFT, RFAGC. 1. When using no SIF circuit: Pin1 = Open Pin2 = GND Pin24 = Open 2. When using no AFT circuit: Pin11 GND Pin14 = Open 3. When using no RFAGC circuit: Connect a capacitor of 0.01 µF across Pin 4 and GND. Pin10 = Open LA7578N Unit (resistance : , capacitance : F) No.4037-5/18 ...
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... LA7578N Interface Circuit LA7578N Unit (resistance : , capacitance : F) No.4037-6/18 ...
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... Therefore, in order to protect against the effects of VCO power supply fluctuations due to this type of noise in the LA7578N, the VCO power supply has been regulated to be constant. The explanation below concerns the PLL detector. A typical PLL detection system consists of the blocks shown in Fig ...
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... If this phase distortion ( ) appears, the PLL VCO will be modulated in synchronization with the error voltage, which causes the generation of a buzz. At Sanyo, this buzz generated by the phase distortion ( ) is called ‘‘Nyquist buzz.’’ The LA7578N includes a new Nyquist buzz canceller circuit that suppresses this Nyquist buzz generated by the phase distortion ( ) in an effort to greatly improve the buzz characteristics ...
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... Design Materials Fig. 5 Fig. 6 De-emphasis 0.01µF Fig. 7 LA7578N Pin 1 (FM detector output) Pin 1 is the audio FM output pin. A 200 in series with the emitter follower. (1) Audio multiplexing applications Depending on the audio multiplexing decoder input application, the input impedance may be low, the L-R signals, etc ...
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... Video Signal Sync rises Fig. 10 Fig. 11 LA7578N Pins 3 and 13 (IF AGC pins) Pins 3 and 13 are the IF AGC filter pins. The signal for which the peak was detected by the AGC detector is smoothed by pin 13 (1st AGC) and pin 3 (2nd AGC) to generate the AGC voltage ...
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... From the above clear that the LiTaO the LiNbO SAW filter is suitable for PAL and U.S. bands where the IF frequency is low. 3 LA7578N Pins 5 and 6 (VIF input) These are the VIF amplifier input pins. The inputs must always have their DC components eliminated with capacitors. The inputs are equilibrium inputs ...
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... LA7578N Fig. 15 Fig. 17 Pin 8 (NC) This pin. When using the LA7577N, this pin becomes the 1st SIF input. Pin 10 (RF AGC output) Pin 10 is the RF AGC output pin. This pin controls the tuner RF AGC. As shown in Fig. 17, a protective resistor of 200 is connected in series with the emitter output ...
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... AFT characteristics AFT characteristics Fig. 19 Fig. 20 LA7578N Pins 11 and 12 (AFT coil) Pins 11 and 12 are the AFT pins. In the quadrature detection system, a signal that has been phase-shifted 90 deg is generated by an external AFT tank, and phase detection is done by the multiplier. The IF signal has the band characteristics shown in Fig ...
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... LA7578N Fig. 21 Fig. 22 Fig. 23 Pins 15 and 16 (VCO tank) These pins are for the VCO tank circuit. The tank circuit capacitor is designed pF recommended. The VCO tank capacitor can be either built into the coil or a component in chip form. This circuit protects VCO from external influences. ...
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... LA7578N Fig. 24 Fig. 25 Series resonance Pins 19, 20, and 21 (EQ amplifier) These pins are for the equalizer amplifier. A signal that has passed through a 4.5 MHz trap is input to pin 19 and is output from pin 21. Pin emitter follower. A resistor must be connected between pin 21 and GND in order to attain satisfactory drive capability ...
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... BPF input and output are close to each other. (B) Bad example Fig. 28 LA7578N Designing the external bleeder resistance ratio so that the output DC voltage (V21) does not change when the voltage is amplified by the equalizer amplifier Assuming the desired gain is Av, then to make Vx 6 V21 so ...
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... As a result, the chip capacitor is affected by the heat, and its capacitance changes. In this case, because the VCO coil is relatively unaffected, the end result is that the alignment point of the VCO tank changes. Accordingly best to use an L with a core material that has small temperature characteristics, and also to use a capacitor with small temperature characteristics. LA7578N 45.75 MHz Picture ...
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... 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 August, 1995. Specifications and information herein are subject to change without notice. LA7578N No.4037-18/18 ...