The SL-RFMOD RF module is a 125K universal read-write base station module designed with its own patented technology. The module and U2270B are very different in terms of usage and performance parameters. This paper simply compares and explains the two products from the aspects of electrical characteristics, application technology and applicability and reliability in the actual industrial production process. I hope to provide a useful reference for your choice of 125K RF card reading and writing solution. The SL-RFMOD uses advanced wide operating voltage circuit technology to operate and read and write cards at any voltage in the 2.7V-5.5V voltage range. The U2270B can only operate in the voltage range of 4.5V-5.5V. Take the water meter as an example: Since the SL-RFMOD can work at a minimum voltage of 2.7V, the customer can use a single-cell lithium-ion battery as the power source to stably read and write the RF card. Moreover, the operating voltage of 2.7V is also consistent with the minimum operating voltage of the M430 series, PIC series and AVRMEGA48/88 series commonly used in water meters. No more protection or conversion circuitry is required in the power supply design of the system. If the customer uses the U2270B as the system for reading and writing the base station, it needs to work at 5V or higher. The system works at this voltage, the power consumption becomes higher, and the effective working voltage range of the battery is also narrower, and it is necessary to consider the discharge due to the battery. Unevenness causes problems such as short battery life. If customers use the SL-RFMOD module, they can design a single-cell high-efficiency lithium battery (or dual lithium battery). The overall working voltage of the customer circuit is low, the instantaneous power consumption is low, and the battery has a long service life, which can effectively reduce the use cost of the water meter. The SL-RFMOD uses a built-in quartz crystal oscillator as the reference clock, and the frequency error is within 150PPM under normal operating conditions. The U2270B uses a built-in RC oscillator circuit to provide the RF reference clock. It is well known that the frequency characteristics of the RC oscillator circuit and the crystal comparison are quite different in terms of stability and temperature coefficient. Therefore, in the read and write circuit of U2270B, a frequency calibration resistor on the RF pin is needed. When necessary, the resistor needs to be adjusted to achieve the desired output frequency. In the production process, the frequency of the radio frequency needs to be tested and adjusted before the product leaves the factory, which greatly increases the complexity of the production process. The U2270B's antenna drive circuit uses direct coupling. A direct consequence of this is that the actual transmit frequency on the antenna also changes when there is an error in the natural frequency of the externally connected resonant tank and the internal clock frequency of the U2270B. In actual production, the consistency of the device and antenna winding is not guaranteed, which will cause deviation of the transmission frequency and affect the reading and writing of the card. The SL-RFMOD module uses a specially designed antenna drive circuit to effectively correct the error in the transmit frequency due to the parametric error of the resonant capacitor and the wound antenna. This gives a lot of room when selecting a resonant circuit that matches the module. Since the frequency consistency of the module is very high, it is not necessary to detect the frequency characteristics of the product during the mass production process of designing the reading and writing device using the module, which can greatly improve the production efficiency and the frequency of the product. Finally, due to the inherent characteristics of the antenna drive circuit of the U2270B, the frequency of the antenna in the actual use process is affected by the external environmental conditions and the position of the RF card in space, besides the influence of the internal RC and the antenna circuit. In practical applications, under certain conditions, the reading and writing of some cards may cause instability or faults. SL-RFMOD has also made a lot of improvements in this area, which can greatly improve the compatibility of reading and writing devices with the use environment and RF cards. Due to the difference in the test environment of domestic RF card manufacturers, many customers in the past have found that there is a problem of picking up RF cards for reading and writing devices. Later, after using the company's modules, this phenomenon has been greatly improved. An important problem that was previously ignored in RF card reading and writing is the suppression of phase noise of the read/write base station. For the U2270B circuit due to its internal practical clock source design issues, as well as external antenna matching errors (actually there is no 100% match). Phase noise is often introduced at the same time as the data is output, that is, illegal pulse hopping occurs in the middle of the normal data stream, which greatly reduces the efficiency of decoding. The specific performance is that when there is no card, it can be found that there will be messy pulse signals on the data output port. These signals will be mixed with the card's real data signal after the card is put on, causing decoding errors. The SL-RFMOD module uses a special modulation and demodulation circuit to effectively avoid phase noise interference with card data. In the case of reasonable antenna transmit power (antenna amplitude between 60V-70V), the effect of phase noise can be completely shielded. The data output port can truly reflect the data waveform of the card. A stable level can be maintained without a card. In this way, the probability of error is greatly reduced, and the efficiency of the card is greatly improved. The direct benefit of the improved efficiency of reading and writing cards is that the transaction time is shortened. From the other side, the working time of the RF module can be saved, and the instantaneous power consumption of the system operation is greatly reduced. If the card is further stable and reliable, the requirements for matching the antenna, card, and module are lower. The stability and mass production of the entire system is more compatible. 1D Barcode Scanner Module,Barcode Reader Arduino,Qr Code Scanner Module,Small Barcode Scanner Module Guangzhou Winson Information Technology Co., Ltd. , https://www.barcodescanner-2d.com