nrf401 wireless transceiver chip application circuit diagram
In this design, the radio frequency module uses the nrf401 wireless transceiver chip launched by Norwegian nordic company. The chip uses the 433mhz ism frequency band and is a true single-chip uhf wireless transceiver integrated chip.In a 20-pin chip, it includes high-frequency transmission, high-frequency reception, pll synthesis, fsk modulation, fsk demodulation, multi-channel switching, etc. , Is currently the most integrated wireless data transmission product [1]. The radio frequency module uses an on-board differential loop antenna. The load impedance of the antenna port is 380ω. The circuit principle is shown in Figure 1. The parameters of each peripheral component are listed in the figure. Among them, the j1 port is the interface between the radio frequency module and the control module.
The design points of the hardware circuit are as follows:
(1) The RF circuit is quite sensitive to power supply noise, and the star wiring method must be used to make the digital part and the rf part have their own power lines, and should be decoupled near the power supply pins of the integrated circuit [2].
(2) High-frequency inductance is selected for external vco electric induction, q> 45, accuracy is 2%, this design uses lqw18an22ng00 of Shenzhen Shunbai Technology Co., Ltd. The accuracy of the inductance has a greater impact on the distance of wireless communication, and can also be used The accuracy is 5%, but the communication distance will be greatly reduced. The vco inductance connection should be kept at a certain distance from other control lines, the digital control line should be avoided from passing between the inductance pins, and the center of the vco inductance element should be about 5.4mm away from the center of the ncof401 vco1, vco2 pin pad The selection and layout of inductive components are very important, and they are the key to the success of the design.
Breaker Rcbo,Rcbo Protection,Leakage Protection Rcbo,Leakage Protection Switch
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