The JW? 7805 is a low noise low-dropout (LDO) voltage regulator with enable function that operates from 1.8V to 5.5V. It provides up to 300mA of output current and offers low-power operation in miniaturized packaging. JW7805 supports fixed output voltage 0.9V, 1.0V, 1.05V, 1.1V,1.2V, 1.3V, 1.35V, 1.5V, 1.8V, 1.85V, 2.1V, 2.2V, 2.3V, 2.5V, 2.6V, 2.7V, 2.8V, 2.85V, 2.9V, 3.0V,3.1V, 3.3V, 3.6V, 4.2V, 4.4V and 5.0V. The features of low quiescent current as low as 6uA and almost zero disable current are ideal for powering the battery equipment. JW7805’s low output noise and high PSRR are also friendly to RF systems.
Abstract: A sliding mode observer and fractional-order phase-locked loop (FO-PLL) method is proposed for the sensorless speed control of a permanent magnet synchronous motor (PMSM).The saturation function is adopted in order to reduce the chattering phenomenon caused by the sliding mode observer. In this proposed FO-PLL, method, a regulable fractional order r is involved, which means that the FO-PLL provides an extra degree of freedom. In fact, the conventional phase-locked loop (PLL) applied in sensorless PMSM control can be seen as a special case of the proposed FO-PLL. By selecting a proper fractional order r a better performance may be achieved. The computer simulation results demonstrate the effectiveness of the proposed method.Key words: fractional calculus; fractional order phase-locked loop; sensorless control; sliding mode observer; permanent magnet synchronous motor; speed controll
INTRODUCTION In the past, adding speech recording and playback capability to a product meant using a digital signal processor or a specialized audio chip. Now, using a simplified Adaptive Differential Pulse Code Modulation(ADPCM) algorithm, these audio capabilities can be added to any PICmicro device. This application note will cover the ADPCM compression and decompression algorithms, performance comparison of all PICmicro devices, and an application using a PIC16C72 micro-controller.DEFINITION OF TERMS step size -value of the step used for quantization of ana-log signals and inverse quantization of a number of steps.quantization -the digital form of an analog input signal is represented by a finite number of steps.adaptive quantization -the step size of a quantizer is dramatically changed with time in order to adapt to a changing input signal.inverse quantizer -a finite number of steps is converted into a digital representation of an analog signal.
摘要：介紹了以FreeModbus協議找在嵌入式搶占實時操作系統μC/OS-l的STM32平臺上，成功實現了Modbus協議的移植。通過詳細分析FreeModbus協議花并編寫STM32F103VET6微處理器的底層驅動，成功實現了工業Modbus協議RTU和ASCll兩種模式的通信功能。測試結果表明，在實際工業生產控制和儀表開發中，應用Freemodbus協議，完全符合工業數據采集、實時控制和數據處理等廠級重復性和精確度要求，在一定程度上降低了工業儀表開發的周期及成本。關鍵詞：實時操作系統，uC/OS-ll，FreeModbus，Modbus協議，STM32Abstract:This paper introduces FreeModbus stack transplanted to the STM32 platform which has been embedded in the preemptive real-time operating system uC/OS-ll，in order that the transplantation of the Modbus protocol is successfuly im-plemented.The FreeModbus stack is analyzed in detail and STM32F103VET6 microprocessor underlying driver is writed，so that the two Modbus industrial communication function RTU and ASCll are successfully realized.Keywords:time operating system，uC/OS-ll，.FreeModbus，Modbus協議，STM32
The GD32F103xx device is a 32-bit general-purpose microcontroller based on the ARM?Cortex?-M3 RISC core with best ratio in terms of processing power, reduced power consumption and peripheral set. The Cortex?-M3 is a next generation processor core whichis tightly coupled with a Nested Vectored Interrupt Controller (NVIC), SysTick timer and advanced debug support.The GD32F103xx device incorporates the ARM ' Cortex?-M3 32-bit processor core operating at 108 MHz frequency with Flash accesses zero wait states to obtain maximumefficiency. It provides up to 3 MB on-chip Flash memory and up to 96 KB SRAM memory. An extensive range of enhanced I/Os and peripherals connected to two APB buses. The devices offer up to three 12-bit ADCs, up to two 12-bit DACs, up to ten general-purpose
