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Audio ICs
Dual preamplifier with ALC
BA3311L
The BA3311L is a dual preamplifier with ALC designed for use in stereo radio-cassette recorders. It comes in a compact
12-pin ZIP package and has two record / playback preamplifiers, and an ALC circuit. The preamplifiers are directly
coupled to the head and do not require coupling capacitors. This prevents tape head magnetization and ”pop” noise
generation.
An ALC circuit with large dynamic range can be constructed with addition of just an external detector and time constant
circuit.
Applications
Stereo radio cassette players
Features
1) The input block uses a bias circuit that does not require coupling capacitors.
2) ALC circuit requires addition of just an external detector and time constant circuit.
Block diagram
3) Wide operating power supply voltage range.
4) High gain.
5) Low noise.
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Audio ICs BA3311L
FAbsolute maximum ratings (Ta = 25_C)
FRecommended operating conditions (Ta = 25_C)
FElectrical characteristics (unless otherwise noted, Ta = 25_C, V
CC = 8V, and f = 1kHz)
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Audio ICs BA3311L
Measurement circuit
Operation notes (the value of the resistor marked with
an asterisk in Fig. 2)
Changing the input resistor Rg, and the ALC time
constant influences the ALC transient characteristics.
In particular, if Rg is less than 3.9kΩ or the time constant
capacitor is less than 47µF , the ALC may operate excessively. Do not use smaller values than those recommended for these components.
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Audio ICs BA3311L
Application example
Electrical characteristics curve
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External dimensions (Units: mm)
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