A buck converter, also called a buck regulator, is a regulator device added to a circuit board as an Integrated Circuit (IC). It is a one of the types of DC-to-DC converters and like the converters, the regulator helps to “balance” or “even out” the current.
There are several variations of this out there and Texas Instruments is one of the leading manufacturers. The company has manufactured a standalone buck converter but this time, it made the TPS54308DDCR into a buck regulator with synchronization features.
If you are looking for an all-around buck regulator that does a combo of power or current regulation and component reduction; you have one here on the TPS54308DDCR.
So, in this article, we are going to talk extensively about how it works.
The Synchronous Operations
TPS54308DDCR is a 28-V, 3-A, synchronous buck converter IC, meaning that it offers multiple functions at once. For emphasis, it supports the following:
- The implementation of a constant-frequency, peak current mode control. This control features helps to reduce the system’s output capacitance.
- It improves the system’s performance both during the load and line transients.
- TPS54308DDCR leverages the optimized internal compensation network to simplify the control loop design and to improve the minimized use of external components.
Advanced Current Protection
There is no doubt that one of the functions of a buck regulator is to simplify the current conversion process. However, TPS54308DDCR implements an advanced form in the form of a cycle-by-cycle current limit.
It is a current-limiting feature implemented on both the high-side MOSFETs. The implementation goes a long way to bolster the TPS54308DDCR system’s protection, when it is operating in an overload or overvoltage mode.
Another part of the current protection is the implementation of the low-side MOSFET freewheeling current limit. It is a “current enhancing feature” that prevents current runaway in TPS54308DDCR.
Just like the above protective features are improving TPS54308DDCR’s current protection, there is also another feature that does it better. The name is Hiccup Mode Protection. It comes in handy when the system has been in an overcurrent or overvoltage current for a long time. When that happens, the Hiccup Mode Protection would be triggered to further protect the system after the overcurrent condition persists.
TPS54308DDCR Reduces Component Counts
More components added to the buck converter could further the expansion and depending on the application, it might not be worthwhile. Therefore, it is pertinent to have measures in place to reduce the proliferation of additional components added into the system.
TPS54308DDCR uses the combination of internal loop compensation, two (3) integrated switching FETs and a 5-ms internal soft start function to reduce the number of components used.
Like Limited Components; Like Smaller Footprints
Just like the TPS54308DDCR reduces component counts, it is also doing that to maintain the smaller footprint design.
By default, the system integrates MOSFETs and use a small-sized SOT-23 package/case. The combo allows for the system to integrated and used with many applications requiring a smaller footprint. Besides, these features also enable the system to achieve a higher power density.
Current Inrush Minimization
It is also possible to minimize or reduce the speed at which current flows into the IC. That is done through TPS54308DDCR’s support for the 5-ms soft-start time function. It helps to regulate the speed of current flowing into the system.
TPS54308DDCR Uses an Overvoltage Comparator
Sometimes, the reason why a circuit board or an electronic device has more voltage than it can handle is because there is no “regulatory device” in place. TPS54308DDCR offers something like that to help keep the voltage or current within “good working conditions.”
The solution offered here is called the overvoltage comparator. As the name signifies, it compares the voltage, especially when it goes above the recommended rating.
To make the most out of this comparator, the system activates the overvoltage comparator when the regulated output voltage is above 118% than the recommended or nominal voltage.
The activation of the overvoltage comparator goes a long way to minimize the excessive output overvoltage transients. However, there is more to how the comparator works. Once the comparator is turned on or activated, it would have to facilitate the switching off of the high-side MOSFET. The MOSFET will remain that way and prevented from self-turning-on, pending when the output voltage is below 104%.
Thermal Shutdown Capabilities
In severe circumstances, it would be expedient to force TPS54308DDCR to shut down. For this to happen, the system must have delegated the Output Overvoltage Protection (OVP) to reduce the extent of releasing the output voltage, pending when the system has been recovered from the strong unload transients.
However, when the overvoltage is not regulated in good time, it would then be up to the thermal shutdown function to force the system to “rest.”
The internal thermal-shutdown circuitry works by forcing the TPS54308DDCR from further switching, especially when the junction temperature is above 165˚C.
Benefits of a Buck Converter
You now know that TPS54308DDCR can help in minimizing the number of components required, balance the current (power) conversion process and improve the system’s performance.
However, there are a couple of other benefits to using it. These are some of them:
1. Lowered BOM Costs
TPS54308DDCR can reduce or save up on the costs of getting Bill of Materials (BOMs) for the target device. The first reason is that it reduces the number of components used in the target device, meaning that it doesn’t need more components that could attract more costs.
The second cost-saving feature is the provision of a wide range of protection features, including an overvoltage, overcurrent and over-temperature features. With these protective features in place, it is certain that TPS54308DDCR will help cut down on the security threats that could hamper the system’s performance.
2. It has Minimum Design Needs
There is little or no need to be “overboard” with designing or configuring TPS54308DDCR. That is because of the limited components needed, the synchronized performances and the adjustable soft-start function.
TPS54308DDCR helps in bolstering power or current switching, via the support for a balanced operating frequency, an excellent output capacitance and a high-switching frequency.