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Video ICs
High-voltage audio head selection switch
BA7755A / BA7755AF
The standard audio circuits of video cassette recorders and the recording circuits of tape decks use AC bias recording to record the audio signal onto the tape. This bias voltage is some tens of volts, and a high-capacity bias-side switch is required to electronically switch the head when in playback or record mode. The BA7755A and BA7755AF are high-voltage switching ICs designed to switch voltages as high as ± 65VDC or AC120VP-P (f = 70Hz). Two control systems, one for current control, and one for voltage control are provided, so the ICs can be used in circuits that employ either method.