All the integrated circuits on a hardware board need to be powered and if we look at the pin configuration of each of them we will see that part of them are designed not to send or receive data, but to power them electrically and make them work. In addition, on that same board we can find a large number of voltage regulator converters, capacitors and other pieces of analog electronics that manage the energy that will be distributed on the board.
When designing hardware, not only the position of the elements according to the architecture is taken into account, but this will also condition the way in which we distribute the rails around it, not only with regard to the distribution of information. , but also from the electricity that runs the entire system.
What is a PMIC?
The acronym PMIC stands for Power Management Integrated Circuit or in Spanish Integrated Circuit for Energy Management. They are used to simplify what is the distribution of the circuitry in the hardware in a very simple way to explain. Each of them receives a single source of energy and is responsible for dividing and distributing it for different elements.
Today, the circuits in order to have a greater energy management have more than one power supply rail, so they will have several pins for it. For example, when a CPU or a GPU is placed in low-consumption modes, what is done is to change the power rail and for this the PMIC is important, since the processor only has to notify the energy manager to stop feeding a pin to feed another, all this without having to turn off the processing unit that makes the request and has to stop working.
In general, when we turn a hardware component on and off or simply increase or decrease its consumption level, a PMIC is served. Not only at the level of several chips in a circuit, but also even within the same integrated circuit such as a processor. Not surprisingly, they are essential for overclocking functions, Boost speed and a long etcetera.
What is a PMIC like?
A PMIC includes a series of elements to perform its functions, including:
- Voltage regulation, since in the variation of the clock speed of the processors and the memory the voltage is directly related. The PMIC is responsible for ensuring that the processor receives the proper voltage at all times and that an overload does not occur.
- Some PMICs include the management of the energy with which a battery powers the system. This is important for laptops, smartphones, tablets, and even peripherals.
- We can find cases where, apart from voltage management, the power management integrated circuit also has the ability to vary the clock speed at which the processor or memory to which they are connected works.
- Many use a real-time clock, for further communication of the exact times to keep voltages and clock speeds high.
The last point is explained in a simple way, integrated circuits count the time in pulse, where each pulse is a clock cycle. We cannot forget that the frequency is the inverse of the time, but in the real world and by standard we count the times by the international system. The fact that there is a real time clock in a PMIC is essential for energy management.
What are its other functions?
PMICs are not only found inside chips or on their motherboard, but we can also find them inside power supplies where their main job is to protect hardware from power surges. If you are lucky enough to have a power supply with 80 Plus Gold certification or higher with protection measures, thank one of these pieces of hardware that we are talking about.
And without leaving the power supplies, they also allow us to use several of them. For example, we may be dealing with a laptop with a USB-C connector for fast charging and a normal one. Thanks to the PMIC we can use both without problems to charge the PC and without leaving the USB they are also key for the power supply of the peripherals that are connected to our computer, and not only those that use the universal serial bus, but also those that they are connected to the PCI Express and SATA ports.
So they are found everywhere and are responsible not only for managing the power of the different parts of your PC, but also that it does not end up being overloaded.
The microcontroller inside the PMIC
Each PMIC has a microcontroller inside it and, therefore, has a self-contained processor with its programmable RAM and ROM memory that executes a program recursively. However, it is possible to update said program and the operation of the PMIC using an I2C interface that they usually integrate for this.
It must be taken into account that the PMIC operates completely isolated from the system, so it is not a peripheral or a component of the same that is directly related to the CPU. So your microcontroller will execute an internal program or another depending on what information comes from outside. If for example an internal thermometer detects that a component is too hot then the PMIC microcontroller will act accordingly, lowering the voltage to lower the clock speed without being prompted by the affected chip.
