Audio ICs
Dual preamplifier with ALC
BA3306
The BA3306 is a dual preamplifier with ALC designed for use in stereo radio...
Audio ICs
Dual preamplifier with ALC
BA3306
The BA3306 is a dual preamplifier with ALC designed for use in stereo radio-cassette recorders and tape recorders. It comes in a compact 9-pin SIP package and has two record / playback pre
amplifiers, and an ALC circuit. The pre
amplifiers have high gain and low distortion, and can be directly coupled to the tape head without coupling
capacitors. This prevents tape head magnetization and “pop” noise generation. The ALC circuit has good channel balance and large dynamic range and can be constructed with addition of just an external detector and time constant circuit. The IC also includes a power-on mute circuit that suppresses “pop” noise generation. FApplications Stereo radio cassette players FFeatures 1) Wide operating power supply
voltage range (VCC = 4.5V to 14V). 2) Low current dissipation (IQ = 2.5mA). 3) High gain (GVO = 80dB). 4) Low distortion (THD = 0.1%). FBlock diagram
5) 6) 7) 8)
Low noise (VNIN = 1µVrms). Input coupling
capacitors and not necessary. Good ALC channel balance. Power-on mute circuit.
FAbsolute maximum ratings (Ta = 25_C)
201
Audio ICs
FRecommended operating conditions (Ta = 25_C)
BA3306
FElectrical characteristics (unless otherwise noted, Ta = 25_C, VCC = 7V, and f= 1kHz)
FMeasurement circuit
202
Audio ICs
FApplication example
BA3306
FCircuit operation (1) Recording (See Fig. 3) For recording, insert an attenuation resistor (3.9kΩ recommended) into the input line. The ALC timing is determined by...