The DC-DC design has basically been applied to most products on the market. No matter how much output current is, there can be a suitable chip to solve it. Many manufacturers have corresponding single-chip solutions from milliamperes to several amperes, but if the output requires 20A, What are the single chips of 30A or higher!
1. Traditional high-current output scheme
In the traditional non-isolated high-current application design, a Buck chip plus an external MOS tube and large inductor are usually used to solve the problem (as shown in the figure below). This application has a large external MOS and inductor volume, especially occupying PCB area. , It is more troublesome to apply in products that require area;
It can be seen from the above figure that the peripheral circuit of the chip is more complicated, and this chip only plays the role of driving the MOS tube. The output current needs to be realized by selecting the appropriate MOS tube, and the switching frequency is generally not high, which makes the output The inductor works at low frequency, the volume will be very large and the price is very high; both MOS selection and external circuit design are relatively troublesome.
Second, a new generation of chip solutions
The principle of the new generation of chips is shown in the figure below. The external MOS tube and inductor in the traditional solution are integrated into the chip. The chip can be used as an LDO in the product circuit. The external circuit is simple and only needs two capacitors and resistors to achieve Applications with an output of 10A or above, and the chip size is small, suitable for occasions that have certain requirements on the volume.
The picture above shows a high-current output chip with built-in inductor of MPS, which can output 20A current, the chip volume is only 12*15*4mm, the temperature rise per 1W loss is only 2.5℃, and the efficiency can be reached when the output is 20A 92%, high efficiency can effectively reduce loss and temperature rise, easy to use in product applications, and meet most of the products.
Three, isolated DC-DC solution
Generally, customers will choose DC-DC isolation modules in places where isolation is required. Zhiyuan Electronics' power isolation module products can achieve different output power requirements. There are suitable products from 0.5W to 50W, and the efficiency is generally around 90%. It is also designed by engineers. The product is the preferred product.
