Dolby IC CX1100 series and Application

Description: Circuit principles and applications within the IC CXA1100 series. The SA1 Dolby switch serves as a recording/release switch. When the switch is placed in the SA2 (R) position, the audio signal is directed into the A amplifier, which amplifies the signal sent to the main channel. Following this, the signal passes through an adder, a variable attenuation circuit, and the auxiliary channel B amplifier. The output signal from the B amplifier is partially sent through a high-pass filter, which merges with the main channel signal in the adder, allowing for the enhancement of high-frequency signals. The remaining portion is processed by the C amplifier, followed by a rectifier filter that feeds into a variable attenuation control circuit to provide a DC electrical voltage. The signal output from the adder is directed through the 8 (9) pin output to the recording head for recording purposes. Additionally, a feedback circuit is implemented to subtract the input signal from the A amplifier, effectively suppressing high-frequency noise.

The CXA1100 series integrated circuits are designed for audio processing applications, particularly in recording and playback systems. The circuit incorporates several key components that work together to ensure high-quality audio output. The SA1 Dolby switch allows users to toggle between recording and playback modes, providing versatility in audio management.

When the circuit is in recording mode, the audio signal is routed through the A amplifier, which is responsible for boosting the signal strength to ensure clarity and fidelity. The amplified signal then enters an adder, where it is combined with signals from other channels, including the auxiliary B channel. The variable attenuation circuit plays a crucial role in adjusting the signal levels to prevent distortion during the mixing process.

The B amplifier further processes the signal, with a portion being directed through a high-pass filter. This filter is essential for eliminating low-frequency noise that may interfere with the audio quality. The filtered signal is then combined with the main channel signal in the adder, allowing for precise control over the audio output characteristics.

The C amplifier and rectifier filter work in tandem to convert the AC audio signals into a DC voltage, which is necessary for controlling various aspects of the audio processing chain. The variable attenuation control circuit modulates this DC voltage, enabling fine-tuning of the output levels.

Finally, the output signal is sent to the recording head, where it is captured for playback or further processing. The feedback circuit enhances the overall performance by subtracting unwanted noise from the input signal, ensuring that the final output is clear and free from high-frequency interference. This comprehensive approach to audio signal management makes the CXA1100 series an effective solution for high-fidelity audio applications. Circuit Principles and Applications within the lC CXA1100 series. FIG SAt Dolby switch, SAz, as recording/release switch. When the recording is placed SA2 (R) position, audio s ignal by l (16) feet into the A amplifier amplifies amplify the signal sent to the main channel, respectively, after the adder, the variable attenuation circuit and the auxiliary channel B amplifier, dried B amplifier output signal - in part through a high-pass filter is crossing into the adder with the main channel signal to the high small signal may be raised; the other part by the C amplifier, rectifier filter rectifier to a variable attenuation control circuit to provide DC electrical voltage. Signal output from the adder, all the way through 8 (9) pin output signal to the recording head as the recording; the other way by the feedback circuit and the input signal to the amplifier A subtraction, high frequency noise is suppressed.