相关元件供应

　　型号：SI4438-C2A-GMR            品牌：SILICON LABS

　　Si4438 EZRadioPRO ISM Band

　　The Si4438 EZRadioPRO ISM Band supports a frequency range between 425 and 525 Hz and output power range between -20 and 20 dBm. The Si4438 is avaialble in a QFN20 package.

　　Silicon Laboratories' Si4438 is a high-performance, low-current transceivers covering the sub-GHz frequency bands from 425 to 525 MHz. The Si4438 is targeted at the Chinese smart meter market and is especially suited for electric meters. This device is footprint- and pin-compatible with the Si446x radios, which provide industry-leading performance for worldwide sub-GHz applications. The radios are part of the EZRadioPRO ® family, which includes a complete line of transmitters, receivers, and transceivers covering a wide range of applications. All parts offer outstanding sensitivity of –124 dBm while achieving extremely low active and standby current consumption. The 58 dB adjacent channel selectivity with 12.5 kHz channel spacing ensures robust receive operation in harsh RF conditions. The Si4438 offers exceptional output power of up to +20 dBm with outstanding TX efficiency. The high output power and sensitivity results in an industry-leading link budget of 144 dB allowing extended ranges and highly robust communication links.

　　目前，随着烟叶质量的不断提高和烤烟生产组织形式的变革，我国烤房设备也在不断创新和发展，普通标准化烟叶烘烤房全面推广应用，智能型烟叶烘烤房已成为烤烟生产可持续发展新形势下的发展方向。

　　在烟叶烘烤过程中，水分的变化对烟叶变黄、定色及烘烤质量影响极大，只有当失水和变黄、定色相协调时，烘烤质量才有保障。水分是鲜烟叶品质在烘烤过程中进一步改进和完善的必备的内因条件之一。适时调节烟叶水分，是烤好烟叶的关键性因素，而烟叶烘烤过程中温度等环境条件的调节，皆需视烟叶的质量和各烘烤阶段烟叶变化程度由人工干预设定。

　　图1：烟叶烘烤控制器系统框图

　　上图为基于Silicon Labs的温湿度传感器Si702x系列产品设计的烟叶烘烤控制器方案框图。该智能烟叶烘烤温湿度控制仪可对烟叶烘烤房内的温度和湿度进行精确采集，并精确控制烘烤时间，实现温湿度的自动检查，完成温度、湿度的分段控制。

　　主机根据烟叶烘烤过程中对温度控制的要求，以烤房内部所测的温度作为测量值与给定温度值进行比较，若测量值低于给定值则发出相应的控制信号，驱动执行机构升温;若测量值高于给定值则驱动执行机构停止升温，从而保证烤房内温度在设定值范围内。同理，当测量的湿度值不在给定湿度值范围时，则控制信号控制排湿设施的启停，使其满足工艺要求;并且当烘烤房内温湿度异常时能够进行报警。烟叶烘烤对温湿度的要求十分严格，需要对温湿度的信息进行记录，所以本方案主机选择Silicon Labs公司EFM32G系列MCU，基于Cortex M3内核其具有超低功耗特性，且配备完全免费的Simplicity Studio集成开发环境，可以快速完成底层驱动代码自动生成，通讯方式可选择有线(RS485/CAN)或无线(Sub-G Si4438/Si4463模块)方式对温湿度及对应的时间进行自动记录，且能够实现单机或多机联网通信。

　　该设计可达到的性能指标：

　　1)温度检测范围：-10~75℃，测温精度：±0.5℃;

　　2)湿度检测范围：20~90%RH，测湿精度：±3.0%RH

　　3)实时显示检测参数

　　4)能够温度门限报警

　　5)能够湿度门限报警

　　6)能够进行声光报警

　　Silicon Labs是由Nav Sooch、Dave Welland和Jeff Scott在1996年于美国德州奥斯汀 (Austin, Texas) 成立，专门开发世界级的混合信号器件。今天，公司已成为营运、销售和设计活动遍及世界各地资本额约5亿美元的上市跨国公司，并且在各种混合信号产品领域居于领先地位。

　　Silicon Laboratories (NASDAQ: SLAB), based in Austin, Texas, designs and develops analog-intensive, mixed-signal integrated circuits (ICs) for a broad range of applications. Silicon Laboratories' diverse portfolio of highly-integrated, patented solutions is developed by a world-class engineering team with unsurpassed expertise in mixed-signal technology.

　　Founded in 1996 on the principles of constant innovation and solid execution, Silicon Laboratories' strong business fundamentals and proven track record have resulted in sustained growth throughout the company's history. Silicon Laboratories consistently introduces best-in-class products implemented in CMOS that dramatically improve the customer value proposition. These products vastly simplify the customer design process and speed time to market by leveraging cutting edge architectures and CMOS process technology to dramatically decrease the size, power and number of components.

　　Silicon Laboratories' diverse portfolio of both application specific and general purpose products serves a broad set of markets and applications. Silicon Laboratories' product portfolio includes high-performance, mixed-signal microcontrollers, digital power controllers, AeroFONE™ Single-Chip Phone, Aero® GSM/GPRS/EDGE transceivers, GSM/GPRS power amplifiers, SiRX™ Satellite Set-Top Box Receivers, FM radio tuners, satellite radio tuners, RF synthesizers, silicon direct access arrangements (DAAs), ISOmodem® embedded modems, ProSLIC® subscriber line interface circuits, DSL analog front end ICs, voice codecs, VCXOs and XOs, SiPHY® transceivers, clock and data recovery ICs and precision clock ICs. Silicon Laboratories' solutions are designed into consumer, industrial, automotive and communications products worldwide including wireless handsets, digital video recorders and central office equipment.

　　Silicon Laboratories is a fabless semiconductor company, enabling it to take advantage of widely available process technology that allows for reliable, mass production of the company's products at the world's most prominent semiconductor foundries.

　　Silicon Laboratories is an ISO-9001 Certified Manufacturer.