In the history of the baby monitor industry, 2.4G digital baby monitors and 40/49M baby monitors occupy the main part. Since the 1980s, the 40/49MHz baby monitor production industry has basically adopted more than a dozen MHz crystal oscillations and then multiplied three times to obtain the working frequency. Filled with many unwanted multiple harmonics and fundamental waves. In order to filter out unwanted frequencies, the desired frequency is usually selected by mid-week tuning. Therefore, the production and debugging are complicated, the defect rate is high, and one crystal is required for one working frequency, and multiple crystals are required for the monitor with multi-channel selection, which increases the production cost and the complexity of mid-week tuning.

Compared with 2.4G digital baby monitors, 40/49M baby monitors have a huge cost advantage so that they always occupy a large proportion of the baby monitor market. However, since most chip design companies' products are aimed at the RF market , so there are very few products that can be applied to 40-49MHz baby monitors. The MCD2006S chip is not only in China, but also in foreign countries.