BA3420

Audio ICs Dual recording / playback preamplifier for radio cassette recorders BA3420AL The BA3420AL is dual recording / playback preamplifier for radio cassette players. It has an internal switch for switching between playback head, mic, and radio input modes, and also includes a bias oscillator and regulated voltage source for radio use. All control is possible with one external switch, allowing designers to reduce the number of external components and the size of their set designs. FApplications Radio cassette recorders FFeatures 1) Internal three-mode input / output switch for playback head, mic and radio modes. 2) Built-in bias oscillator and regulated voltage source for radio use. 3) Control of the internal switch and regulated voltage source is possible with one external switch. 4) Low distortion. 5) Low noise. FAbsolute maximum ratings (Ta = 25_C) FRecommended operating conditions (Ta = 25_C) 243 Audio ICs FBlock diagram BA3420AL 244 Audio ICs BA3420AL FElectrical characteristics (unless otherwise noted, Ta = 25_C, VCC = 8.0V, f = 1kHz and measurement circuit: Fig. 1) 245 Audio ICs FMeasurement circuit BA3420AL FMeasurement circuit switch control table 246 Audio ICs BA3420AL 247 Audio ICs FApplication example 1 BA3420AL FApplication block diagram 248 Audio ICs FApplication example 2 BA3420AL 249 Audio ICs FElectrical characteristics curves BA3420AL FExternal dimensions (Units: mm) 250