Is There Any Way To Prevent Overloading The Regulator?

No matter what product it is, reliability is extremely important, which is directly related to the cost of repair and maintenance. In order to ensure that Automatic Voltage Regulator has a high degree of reliability, a current limiting protection circuit is required during the design, which is to prevent excessive load from causing long-term damage to the voltage regulator.

There are two general current limiting protection measures:

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

2. Reduce the output current while reducing the voltage. The advantage is that the energy consumed during operation is small, but the limitation is not obvious, and there will still be current passing, which will accelerate the aging of the device.

In this circuit design, VMP is the power MOS tube of the linear regulator. When a short circuit occurs, when the voltage regulator achieves short-circuit protection, the VM1 tube will be cut off and re-formed into a current mirror. The role of the transistor is to ensure that the circuit can input voltage normally during the short circuit, thereby ensuring that the voltage is always in a low voltage state and improving the reliability of the circuit.

Based on the current limiting circuit, after improvement, it can ensure the high reliability of the voltage regulator and reduce losses, and is well applied in power management!