Home>>Core Technology>> Innovated IC applied for 40/49MHz baby monitor

       Baby monitor adopts modern wireless technology and has been widely used in Europe and the North American for 30 years. It is a very good helper for monitoring the babies. With the use of the baby monitor, there is no need for mothers to walk around at times to check the baby’s status. Only with a transmitter set beside the baby, and a receiver lain in mother’s room or mother carrying a receiver, in a effective range of several meters to hundreds of metres, mother can go to garden for planting or kitchen for cooking; and when the baby upstairs cries, mother can know it timely. Baby monitor is not only a good baby-sitter, but also a good helper for the elder and patients.

 

　　With rapid economic development and unceasing update of electronic products and fierce competition among companies, the product cost control has become very important for consumer products. Compared to 2.4G digital baby monitor, with advantage of low cost, the 40/49MHz baby monitor occupys a large proportion of market share.

     

　　Since 1980s, 40/49MHz baby monitor manufacturers have used a dozen MHz crystal oscillation, and got frequency via frequency tripling. The advantages of this technology are: simpleness and low cost. But frenquency tripling causes unnecessary harmonic and fundamental interference in the circuit. In order to get rid of the useless frequency, quad coil is usually adopted to select frequency, which leads to complex debugging and low qualification rate. In addition, a corresponding crystal is needed for a frequency channel. Therefore, for baby monitors with multiple frequency channels, multiple crystals are necessary, which leads to higher cost and tuning complexity.

 

     Since most of IC design companies aim at RF market, there are few products applied for 40/49MHz baby monitor. In order to simplify debugging procedure, to improve yield, and to reduce the production cost, MC Devices developed a high integration IC with new technology, which is used in transmitter and receiver. High Integration IC brings an unprecedented technological revolution in baby monitor production.

 

Technical Revolution with High Integration IC

 

	Patent IC	Traditional technology
Frequency point	Multiple frequency selection is possible without increasing cost and production difficulty.	More crystal and relavant components for more frequencies. Production difficulty is increased with more frequencies.
Multiple frequency adjustment	By changing high or low LC level control according to logic table, Patented IC can select frequency without adjustment.	Every frequency needs intermediate frequency adjustment.
Precision	The precision of different frequency is the same, as it only depending on crystal precision.	The precision of different frequency points may not be the same, as it depends on not only crystal, but also intermediate frequency tuning.
Adjust difficulty	Very easy	Complicated, intermediate frequency Q value determines its sensitivity, so transmitter and receiver are needed to be adjusted to guarantee the frequency correspondence and sensitivity.
Integration	The main function is performed by IC and module, the consumers only needs to connect the external audio circuit.	Only one intermediate frequency modulation IC is used. Other functions are performed by quad coil, crystal and divider.
Crystal selection	Only one crystal with high precision needed.	Each frequency needs one crystal with high precision.