BA3413FS NAB120 - Datasheet Archive

 

1.5V dual auto-reverse preamplifier BA3413FS The BA3413FS is a 1.5V dual auto-reverse preamplifier designed for playback

 

Audio ICs 1.5V dual auto-reverse preamplifier BA3413FS BA3413FS The BA3413FS BA3413FS is a 1.5V dual auto-reverse preamplifier designed for playback operation only. It includes built-in circuits for metal tape and auto-reverse applications, and its significantly streamlined component side offers a minimal requirement for external components. FApplications 1.5V headphone stereos FFeatures 1) Low noise. 2) Can be directly coupled to the tape head. 3) Supports auto-reverse. 4) Supports metal tape. 5) Good reduced voltage characteristics (0.9V Typ.). FBlock diagram 235 Audio ICs FAbsolute maximum ratings (Ta = 25_C) FRecommended operating conditions (Ta = 25_C) FElectrical characteristics (unless otherwise noted, Ta = 25_C, VCC = 1.25V, and f = 1kHz) 236 BA3413FS BA3413FS Audio ICs BA3413FS BA3413FS FMeasurement circuit FApplication example 237 Audio ICs FCircuit operation (1) Input stage At the input stage the pin 4 bias is the input and the negative feedback virtual earth, and the bias for the input stage transistor is taken from pin 4. This allows direct head coupling. Connect a 1000pF capacitor in parallel with the tape head to prevent high-frequency interference. (2) Input switching The auto-reverse switching circuit switches the constant current supply for the first-stage transistor, and responds depending on whether pin 9 is open circuit or connected to GND. The reverse timing can be adjusted by changing the value of the capacitor connected to pin 8 (see Fig. 3). (3) Equalizer The equalizer is based on a NAB120 NAB120µS NF-type equalizer, and has 70µS muting added for metal tape applications. The equalizer constants can be changed by switching pin 13 between open circuit and VCC (see Fig. 4). FElectrical characteristics curves (Ta = 25_C) 238 BA3413FS BA3413FS Audio ICs BA3413FS BA3413FS FExternal dimensions (Units: mm) 239