Relationship and Difference between HC-49S & HC-49U & HC-49SMD

First of all, HC-49S & HC-49U & HC-49SMD are all quartz crystal package types. Passive crystal series are the most widely used products of quartz crystals nowadays, due to their lower cost, accuracy and stability. Therefore, it is still widely used.

HC-49S is a direct plug-in quartz crystal package with 2 pins and a volume of 11.5 * 4.5 * 3.5mm. At present, YXC can also provide a small volume of HC-49XS (7.0 * 4.0 * 1.5mm), standard load capacitance is 20PF, accuracy is ± 20PPM ± 50ppm, etc., resistance is 120Ω, and the
parameter standard is no different from HC-49U 49SMD. Also called HC-49US package.

HC-49U is also a direct plug-in 2-pin crystal, with a volume of 11.05 * 4.65 * 13.46mm. Its functional applications are almost the same as HC-49S. Because the size is larger than 49S, the waste of circuit board space and the cost of production are relatively large. It should be noted that HC-49U is different from HC-49US. HC-49US refers to HC-49S instead of 49U.

HC-49SMD, commonly known as "fake smd", this is a smd type 2-pin crystal, other than the pin, other parameters are the same as HC-49S, the volume is 11.4 * 4.8 * 3.8mm. To be precise, HC-49SMD is processed by HC-49S flattening feet-set gaskets-shear feet compacting-taping and other production processes. Due to the increase of materials and processing costs, it will cost more than HC-49S and more expensive. Its advantage is that no manual welding is required, and the production speed is faster. Hotselling frequency include 8MHZ 12MHZ 11.0592M 13.560MHZ and so on.