Power Supply Management in Custom Power Supplies

Embedded engineers must be aware of the various nuances of power management, especially when they are using a custom power supply.

Operational reliability in an electrical device is determined by various factors. Is the voltage rail above a certain threshold? Is it powered off or on? Is it in the proper sequence in connection with other rails? All these things are important.

The number of power supply voltage rails in applications is steadily increasing. Embedded engineers must look out for each of them. The safety, operation, durability and economy of the electronic system depend on it.

A part of this problem is solved by using flexible sequencing, supply monitoring and adjustment circuits to keep track of the system. There are many other methods to solve this issue. You can determine if a voltage rail is above/below a threshold by using a resistive divider and comparator.

In some custom power supplies, a delay switch is employed to hold some devices (digital signal processors, application specific ICs and microprocessors) in reset. On the opposite end, if you want to monitor multiple rails, you have to use multiple devices in parallel.

At the same time, we are seeing a rising demand for ICs that can perform more than threshold comparisons. This kind of monitoring is enough for most electrical devices.