The IC described here is particularly designed for single audio channels, so as to offer Dolby B-type noise-reduction features. Along with the internal power supply regulator, the circuit of dolby noise reduction processor IC requires a series of amplifiers. In addition to this, some external RC networks are also required for the system.
These networks serve a special purpose in the system. A single network comprising five capacitors and three resistors is connected to four external leads. The other network which constitutes of three resistors and three capacitors forms a feedback path and works with an internal rectifier circuit. The circuit of dolby noise reduction processor provides extra flexibility with the fact that the specified RC networks are already prescribed accordingly in details by the manufacturer such that the desired Dolby B-type noise-reduction effect can be obtained effortlessly.
However, one must be careful with the values of external resistor and capacitors and tolerances used in the system to ensure proper functioning of the system and achieve desired effect.
Key parameters which elaborate this system dolby noise reduction processor more clearly are briefed hereby:
- Distortion level- the maximum distortion offered by IC-
For 1 KHz, 0db level input, distortion= 0.05%
For 10 KHz, 10 db level input, distortion= 0.1%
- Signal handling- the signal handling capacity indicates the dynamic range of the signal for 0.3% distortion level at 1 KHz. For this system, 14 db is considered general value.
- Signal-to-noise ratio(SNR)-
For encode mode of operation, SNR=70 db
For decode mode of operation, SNR=80 db
- Input resistance-
General value= 65k ohms
- Output resistance-
General value= 80 to 100 ohms
Applications of dolby noise reduction processor:
Can be used at any places where Dolby type of noise reduction is preferred, like in any kind of hi-fi audio system, recording devices, FM receivers, etc,