How to prevent the voltage regulator from overloading without damaging the voltage regulator?

    No matter what the product is, reliability is extremely important, which is directly related to the cost of maintenance. In order to ensure the high reliability of the regulator, the following steps should be taken:

    In order to prevent the voltage regulator from being damaged for a long time due to excessive load, a current-limiting protection circuit is needed in the design.

    There are two general methods of current limiting protection measures:

    1. Limit the output current to the maximum value. The disadvantage of this method lies in the large internal loss.

    2. It reduces the output current while lowering the voltage. The advantage is that the energy consumption is small, but the limitation is not obvious, there will still be current passing through, which will increase.

    Aging of speed devices.

    So what should we do?

    In view of this situation, Sichuan Steady Power Generator suggests that on the basis of current limitation, we should improve the lower short-circuit protection circuit and disconnect the power MOS under the condition of ensuring short-circuit.

    Well, that's the way it works. Specifically, see below for more details:

    In this circuit design, VMP is a power MOS transistor of linear regulator. When short-circuit occurs, when the regulator realizes short-circuit protection, VM1 transistor will be.

    The purpose of the transistor is to ensure that the input voltage of the circuit is normal during the short circuit, so that the voltage is always low.

    Voltage state, improve the reliability of the circuit.

    On the basis of current limiting circuit, after improvement, it can ensure the high reliability of voltage regulator and reduce the loss. It has been well applied in power management.