At this stage, it is necessary to strictly control the damage of static electricity to the tested products. This link is prone to loopholes, and foreign traders of rigid-flex boards should be careful!
Test data is required before testing. Our API manager, test data and I2C bus are used to determine the electrostatic discharge voltage of the object code, and must meet the following requirements.
Determine the voltage range of electrostatic discharge: 20mV/V~200mA;
● Planarity: The insulation resistance value between two power supplies connected to the power supply surface is greater than 70M Ω.
Short circuit detection: allows the current signal to be released through a sufficiently large resistor and short-circuit to the ground after a short circuit occurs. As shown in the above figure, if the DC supply voltage of a certain power supply is known to be 220V, then when the power supply is turned on, the DC supply voltage becomes 220V, and the current flowing through is 240V.
This situation is very common, usually due to power supply issues, or it may be due to power supply faults. At this time, setting the DC power supply voltage above or below 220V may be due to the power supply voltage not reaching stable conditions when the power supply voltage increases or decreases, or the load is too heavy, causing the output voltage of the power supply to be lower than the working voltage.
When measuring the power supply voltage and conducting inspections, it is important to pay attention to whether the voltage is normal and ensure that there is no voltage difference between the output terminal and the voltage of the electrostatic precipitator transformer.
It should be noted that the voltage amplitude measured at this time is lower than the normal value, and the voltage measured this time is higher than the normal value, otherwise there may be hidden dangers.
When the voltage is lower than the withstand voltage, the output current of the regulated power supply will be greater than the saturation current, and the current (Tj) at this time will have an impact on the loss of the regulated power supply.
Therefore, qualification has a direct impact on the efficiency and reliability of the regulated power supply, but it is also a key factor affecting the performance of the regulator.
The variation of load current, through the variation of current limiting resistor, has a direct impact on the maximum transient voltage drop of the regulated power supply.
Therefore, when the input voltage is higher than the negative pressure of the regulated power supply, system harmonics will increase the ripple rate of the regulated power supply. This is because the parasitic capacitance inside the regulated power supply usually forms an LC oscillation circuit between the input and output, and its frequency change will also cause voltage drop, causing the input ripple to exceed the limit.
The high-frequency RC oscillation generated inside the regulated power supply belongs to radio frequency interference (EMI) interference. It couples to the load through the output end, causing distortion of the output voltage waveform, increasing the high-frequency harmonic component on the load, reducing the output voltage at the load end, and increasing the output voltage.
Power supply noise is a type of electromagnetic interference, which occurs when the voltage of certain component pins exceeds a certain amplitude, causing electromagnetic interference and interference sources. The equivalent impedance should meet the requirements of EMC standards. The loop interference of the power supply is usually microsignal, which mainly includes the loop current of the upper and lower edges. If the loop current is unbalanced, it is the interference of the loop current. To have good loop interference, we will analyze it in sequence below.