Grounding switches DC devices, to a large extent that is, will integrate the switching regulator Topswitch family. DC devices for this earthing switch provide exceptional performance in small or pin-count packages. For a minimum pin package, the Multi-Function (M) pin is also used for a variety of purposes, including switching control, under-voltage, or over-voltage input detection.
The DC device for earthing switches also allows the use of a ground switch that is sometimes more convenient than the control pin to control the voltage regulator switch. In the case of mechanical switches, the circuit does not need an external power supply to achieve this function. This feature application is particularly important, Topswitch's power supply is considered a single power supply. In terms of the circuit, to a large extent, that is, it will not interfere with M or L pin over-voltage and under-voltage function.
To understand the function of the circuit on a DC device for a grounding switch, that is, to interpret the internal working principle of the M or L pin. This pin functions as a constant voltage source close to 2V DC and minimizes the external circuit current provided by RLS. The internal current-sensitive limit for overvoltage and undervoltage detection is roughly 50μA, with an undervoltage of 30μA and an overvoltage hysteresis of 225μA.
In summary, the DC output of the grounding switch is in use, when the current flowing into the M or L pin is less than 30μA or 30 ~ 50μA, the regulator output appears to be closed due to undervoltage . When the current into the M or L pin is 225μA, the regulator output is turned off due to overvoltage. When the current flowing into the M or L pin is 50 to 225μA, the output is enabled.
The use of dc devices for earthing switches, ie because of the short circuit of a conventional generator, can be regarded as a serious accident, since large currents tend to damage the generator to varying degrees, but the way in which such generators operate normally That is, frequent short-circuits occur, and try to produce as large a current as possible, this time the application of DC grounding switch equipment, which is to ensure that the generator can not only generate high current up to 140 kA, but also in the cycle After the huge impact is still safe and sound.