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參數(shù)資料
| 型號： | LA1245 |
| 元件分類： | 接收器 |
| 英文描述： | AUDIO SINGLE CHIP RECEIVER, PDIP20 |
| 封裝： | 0.300 INCH, DIP-20 |
| 文件頁數(shù)： | 6/12頁 |
| 文件大?。?/td> | 712K |
| 代理商： | LA1245 |
LA1245
No. 737-3/12
Package Dimensions
unit : mm (typ)
3021C
Using the automatic search-stop signal
Signal Meter-driving output circuit is equivalent to Figure. 1, signal meter driving output (abbreviated as VSM) is
narrowed in band width and can be used as an automatic search-stop signal when a narrow band series resonator is
connected to pin 15. VSM can be adjusted with R208 and R211 both in wide band and narrow band since R208 is
inversely proportional to VSM, while R211 is proportional to VSM. R208 is related to the Q of narrow band signal
meter. When the resistance of R208 is increased, the Q will be damped and the band width increased. On the other hand,
R211 used as the output impeadance of VSM and affects the cut-off frequency and time constant of low pass filter for
VSM and the meter drive impedance. The time constant τ and the cut-off frequency fc can be expressed as follows :
τ = (C114+C115+CS) × (R211//Rin)
fc =
1
2
πτ
where CS is the input capacitance of the pin 16 peripherals and the meter drive circuit, and Rin is the input resistance of
the meter drive circuit.
A semi-fixed resistor is recommended to be used as R211 to cope with the fluctuation of VSM. Refer to Figure. 3 for
the value of the semi-fixed resistor since this depends upon VSM and R208. Figure. 3 shows the lowest limit of the
semi-fixed resistor in relation to R208 with the parameter of VSM set point, and the value of the semi-fixed resistor will
be equal to or greater than that shown in Figure. 3. For example, when VSM = 5V and R208 = 240Ω, R211 becomes
28k
Ω. Thus, the value of the semi-fixed resistor is determined to be about 30kΩ. When the value of VSM is too large,
it is limited and saturated to the source voltage so it is recommended to follow the condition of VSM ≤ VCC–2(V).
When a narrow band serial resonator is used, include the resonant impedance to determine the value of R208.
Figure. 1 Signal Meter Detector Circuit
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PDF描述 |
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| LA1247 | AM, AUDIO SINGLE CHIP RECEIVER, PDIP20 |
| LA1260 | AM/FM, AUDIO SINGLE CHIP RECEIVER, PDIP16 |
| LA1265 | AM/FM, AUDIO SINGLE CHIP RECEIVER, PDIP22 |
| LA1266 | AM/FM, AUDIO SINGLE CHIP RECEIVER, PDIP24 |
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相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LA1247 | 制造商:SANYO 制造商全稱:Sanyo Semicon Device 功能描述:AM ELECTRONIC TUNER |
| LA12540 | 制造商:LIGITEK 制造商全稱:LIGITEK electronics co., ltd. 功能描述:ROUND TYPE LED LAMPS |
| LA12540-PF-TBF-X | 制造商:LIGITEK 制造商全稱:LIGITEK electronics co., ltd. 功能描述:TAPE AND BOX TYPE LED LAMPS |
| LA1256 | 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Octal Peripheral Driver |
| LA125P | 制造商:LEM 制造商全稱:LEM 功能描述:CURRENT TRANSDUCER LA 125-P |
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