AVK200 home theater amplifier and maintenance 04

 (4) The Dolby decoding circuit
  AV K20 0 decoding chip uses NJW1102 from Japan's JRC Company. The decoding circuit is shown in Figure 10-25.
The data sent by 1N2 is input to the @~@ pins of 2N4 through lxl, so that 2N4 makes corresponding state changes;
    three sound field modes: 2CH (i.e. traditional stereo mode); Than 3 STEREO (in this mode, the surround channels do not work
); Dolby Pro Logic state.
    Three center modes: normal mode (NORM), wideband mode (WIDE), and phantom mode (PHANTOM). In phantom
mode, the + center channel does not work, and the center signal is assigned to the left and right channels.
    Four-speed surround delay: 15ms, 20ms, 25ms, 30ms o
    Noise sequence test <TEST)々