Isolated and non-isolated power supply characteristics PK

    If the CPU is likened to the brain of the electronic system, then the power supply is equivalent to the heart of the electronic system. With the increasing demand for power supply in circuit design, isolated power module came into being, and how much do you know about isolated power supply?
    With the development of the electronics industry, the demand for power is getting higher and higher, smaller and more reliable, and the power module as an integrated device came into being. It has the advantages of isolation, strong anti-interference ability, built-in protection function, convenient for later system integration and so on, which are more and more widely used.
    However, when choosing the right module, often encounter a parameter "isolation voltage", the higher the isolation voltage, the more expensive the price of the module, then you will be curious, what is the isolation voltage, what level of the appropriate choice?
    The isolation voltage of the power supply is also called the electrical strength in the GB-4943 national standard, this GB-4943 standard is what we often say is the safety standard of information equipment, which is to prevent personnel from physical and electrical damage to the national standard, including to avoid people from electric shock injury, physical injury, explosion and other injuries. Figure 1 below shows the structure of the isolated power supply.     As an important indicator of the module power supply, the standard also specifies the isolation voltage withstand related test methods. The simple test generally adopts the equal potential connection test. The connection diagram is as follows:     Test method:
    Set the voltage of the voltage gauge to the specified voltage value, the current to the specified leakage current value, and the time to the specified test time value;
    l Operate the pressure gauge to start the test, start the pressure, within the specified test time, the module should have no breakdown, no arc phenomenon.
    When welding the power module during the test, select a proper temperature to avoid damage to the power module due to repeated welding.
    So what are the advantages and disadvantages of isolated power supply compared with non-isolated power supply?     By understanding the advantages and disadvantages of isolated and non-isolated power supplies, each has its own advantages, and for some common embedded power supply options, we can follow the following criteria:
    l The power supply of the front stage of the system, in order to improve anti-interference performance and ensure reliability, isolation power supply is generally used;
    l The IC or part of the circuit power supply in the circuit board, from the cost performance and volume, the non-isolated solution is preferred;
    For the power supply of remote industrial communications, in order to effectively reduce the impact of ground potential difference and wire coupling interference, isolation power is generally used to supply power to each communication node separately;