The introduction of gallium nitride power devices was first applied to fast charger chargers. The advantages of gaN fast switching improve the switching frequency of the charger, reduce the volume of the transformer, and reduce the heat dissipation requirements of the device, thereby significantly reducing the volume of the charger, so that the charger has greater output power, more output interface, and is loved by consumers.
After the introduction of high-voltage GaN devices and widely used, Innosecco aims at the low-voltage market and launches INN040W040A low-pressure gallium nitride devices, which have 40V withstand voltage, conductivity resistance of only 4mΩ, with the advantages of gallium nitride without reverse recovery, gate charge is only less than one-half of the same specification silicon MOS, which can reduce the controller drive pressure and shorten the dead time. It also supports higher switching frequencies, reducing circuit size and improving conversion efficiency.
For the car charging market, there are very few car chargers that support 100 watts of high-power output, and car charging with 65-100W high-power output can provide an ideal charging effect equivalent to the original fast charger of the device. However, due to the physical properties of silicon MOS, the frequency is low, the loss is large, there are few related products, and the price is also higher. Innosyco's low-pressure gallium nitride devices can replace traditional silicon MOS in autocharging and notebook applications, improving conversion efficiency while increasing power density, reducing size and meeting more demand.
Innosecco has introduced a synchronous buck-boost reference design using low-pressure Gallium nitride devices that supports a 12-24V input voltage range, an output of 3.3-19.2V, and 150W of output power to meet the needs of 100 watts of high-power vehicle charging, notebook built-in charging, and high-power fast-charging mobile power applications. The high-frequency advantage of gallium nitride can operate at 1.2MHz frequency, reducing the inductance and filter capacitor volume, meeting the small volume and ultra-thin design, providing a stronger competitiveness for the product.
Innosecco 150W Gallium Nitride Buck-Boost Reference Design Analysis
Innosyco's 150W Gallium Nitride Buck-Boost Reference Design uses the NANSC8886S Synchronous Buck-Boost Controller to drive four Innosyco INN040W040A H-bridges for synchronous buck-boost voltage conversion. In the middle of the PCB board is a 2.2μH alloy inductor, and the input and output are filtered using multiple 0805 package MLCC.
There are only a few resistive capacity discrete elements and two diodes on the back.
Reference design at a glance where input and DC outputs are welded to terminal posts, battery outputs are unused, and the top pad is a voltage test point.
Four Innosecco gallium nitride switch tubes are lined up to form an H-bridge, and the large-area vias at the edge of the chip are dissipated by PCB assistance. INN040W040A adopts CSP package, which has good thermal performance and small package area.
Synchronous buck-boost controller adopts Nanxin SC8886S, which is the first synchronous buck-boost charging chip supporting NVDC in China, which supports 5-24V input voltage, supports 1-4 strings of lithium battery charging, charging output current up to 8A, and supports I2C digital communication. The SC8886S includes eight 10-bit ADCs that support detailed system parameter acquisition.
The buck-boost inductor uses a 10*10mm size, 2.2μH inductor. The advantages of low switching loss of gallium nitride support high switching frequency, and high switching frequency can use a small inductance inductance, reduce inductive copper loss, and improve conversion efficiency.
Multiple MLCCs on the input side are filtered in parallel.
The output side is also filtered by multiple MLCCs.
The BAT FET for controlling the battery is controlled by the South Core SC8886S.
Close-up of the I2C interface pin, configure the parameters through the I2C interface.
Innosecco 150W Gallium Nitride Buck-Boost Reference Design Test
Using a 24V input to simulate the actual use environment of the car charging, the reference design switching frequency is set to 600KHz, and the output voltage is selected 5, 9, 12, 15, 20V five-speed PD fast charging voltage, and the efficiency is improved as the output voltage difference is reduced. For 20V5A, the conversion efficiency is as high as 98% at 100W output, which means that the power consumption on the reference design is only 2W, which greatly simplifies the thermal design of high-power car charging.
In the 12V input environment, the output efficiency corresponding to 12V and 15V is the highest, which is very suitable for PPS mobile phone fast charging. At a 12V input, the boost efficiency corresponding to the 20V5A output is still 97%. The application of gallium nitride is very obvious for the conversion efficiency improvement.
Charging head net summary
The internal design of many portable charging devices on the market is very compact, and the corresponding power supply device area is getting smaller and smaller. Using high-frequency drives on traditional silicon devices can significantly reduce efficiency and hinder power gains. The application of low-pressure Gallium nitride devices solves the problem of reducing efficiency, and can further increase the frequency, using a smaller inductor, and reducing the footprint area.
Innosyco low-pressure Gallium Nitride devices can be used not only in synchronous buck-boost, logic-driven gates, but also in synchronous boost, synchronous buck and lithium battery protection applications. In the switching circuit, we give full play to the advantages of low conductivity and fast switching speed of gallium nitride, increase the frequency and reduce losses, provide more efficient and competitive terminal solutions, support more personalized design, and also contribute to carbon neutrality and carbon emission reduction.