BA3426S [ROHM]
Double cassette tape recorder system preamplifier; 双盒式磁带录音机系统前置放大器型号: | BA3426S |
厂家: | ROHM |
描述: | Double cassette tape recorder system preamplifier |
文件: | 总12页 (文件大小:300K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
Audio ICs
Double cassette tape recorder system
preamplifier
BA3426AS
The BA3426AS is a record/playback system preamplifier for radio cassette decks. It also has a CD input. It has three
control switches for function and tape mode switching and mic on/off.
It requires far fewer external components than its predecessors which means simplified assembly and overall savings.
FApplications
Dual-cassette radio cassette players.
FFeatures
1) Built-in switch for recording/playback equalize.
2) Motor control output provided.
3) CD input.
4) Smoothing capacitors to suppress switching noise
are not required.
5) Built-in bias oscillator transistor.
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BA3426AS
FBlock diagram
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BA3426AS
FPin descriptions
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BA3426AS
FElectrical characteristics (unless otherwise noted, Ta = 25_C, VCC = 5.5V, f = 1kHz, Rg = 680Ω,
Tape input = *66dBm, Mic. input = *50dBm, and Radio input = *23dBm,
and CD input = *12dBm)
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BA3426AS
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BA3426AS
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BA3426AS
FMeasurement circuit
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BA3426AS
FCircuit operation
(1) Control pins
The control pin inputs and the corresponding states of the various inputs and outputs are summarized in the input/output
pin status table that follows.
Control pin inputs and corresponding input/output pin states
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BA3426AS
FApplication example 1
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BA3426AS
FApplication example 2
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BA3426AS
FOperation notes
(1) Amplifier oscillation
(2) Strong RF signals
As the BA3426AS incorporates dual-cassette dubbing
functions on a single IC, it has extremely high input/out-
put gain. In particular, in normal-speed mode, the gain at
around the recording equalizer peaking characteristic fo
frequency is about 70dB. The phases of the input and
output are reversed to reduce the chance of oscillation
due to influence of the PCB pattern, but due consider-
ation must be given to the PCB pattern design to prevent
oscillation. In particular, the PCB tracks to the Tape A
pins (pins 1 and 4) and Tape B pins (pins 31 and 32)
should be sufficiently far apart that there is no coupling
capacitancebetween them, or they should be shieded by
having a GND or bias track between them.
Topreventsignalmixingduetostrongelectricfields, con-
nect a capacitor (of a few hundred pF) to each input pin.
These must be connected close to the pins of the IC to
have any effect. Design the PCB track layout so that the
capacitors can be connected as close to the base of the
pins as possible.
FElectrical characteristics curves
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Audio ICs
BA3426AS
FExternal dimensions (Units: mm)
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