浅析耗尽型MOSFET对智能变送器中DAC的供电与保护

Analysis of Power Supply and Protection of Depletion MOSFET for DAC in Intelligent Transmitter

具有ESD保护功能的耗尽型MOSFET代替JFET器件和普通耗尽型MOSFET,能有效抑制各种干扰,极大提高整个系统的稳定性和安全性。由于智能变送器在工业控制、物联网、轨道交通、航空航天等领域的广泛应用,特别是近年自动驾驶汽车、医疗仪器和能源环境控制系统应用的日益普及,系统智能化、集成化、小型化的发展趋势对智能变送器的性能、品质要求不断提高,关键模块DAC在恶劣环境下有效的抗干扰能力是整个变送器工作稳定、系统安全的重要保障。传统的JFET器件能实现稳定供电,但不能起到有效的抗干扰作用。普通耗尽型MOSFET器件替代传统的JFET器件,能稳定供电,并能有效抑制浪涌、瞬态电流、电压干扰,但没有静电防护功能。为更有效解决系统电路保护的问题,通过对器件本身结构进行研究,开发自带ESD保护功能的耗尽型MOSFET。在实际测试和使用中有效验证了该器件对DAC模块的供电,不仅能稳定供电,抑制浪涌、瞬态电流、电压干扰,而且能有效消除静电对器件的损坏可能性。该器件的应用大大提高了智能变送器的稳定性,对自动驾驶汽车和医疗仪器的安全性有重要作用。

The depletion MOSFET with ESD protection replaces the JFET devices and ordinary depletion MOSFET,effectively suppresses various interferences, and greatly improves the safety and stability of the whole system.Due to the wide application of intelligent transmitters in industrial control, Internet of things, rail transit, aerospace and other fields, especially the increasing popularity of the application of autonomous vehicle, medical instruments and energy and environmental control systems in recent years, the development trend of intelligent, integrated and miniaturized systems, and the continuous improvement of the performance and quality requirements of intelligent transmitters, The effective anti-interference ability of the key module DAC in harsh environment is an important guarantee for the stability of the whole transmitter and the safety of the system. Traditional JFET devices can achieve stable power supply, but can not play an effective anti-interference role. Ordinary depletion MOSFET devices replace traditional JFET devices, which can stabilize power supply and effectively suppress surge,transient current and voltage interference, but have no ESD(Electro-Static discharge) protection function. In order to solve the problem of more effective protection of the system circuit, the structure of the device itself is studied and the depletion MOSFET with electrostatic discharge protection function is developed. In the actual test and use, it is effectively verified that the power supply of the device to the DAC module can not only stabilize the power supply, but also suppress the surge,transient current and voltage interference, and effectively eliminate the possibility of electrostatic damage to the device. The application of the device greatly improves the stability of intelligent transmitter and plays an important role in the safety of autopilot system vehicle and medical instruments.