Rohm EcoGaN™ Power Stage IC: Reduced power loss by 55% and device volume by 99%

Type C Pd Qc Charger / 10 Port Type-C HUB 3.0 / 300W USB charging station 

For the primary side Power supply of industrial equipment such as data servers and consumer electronic devices such as AC adapters, Romm has developed a new set of 650V products - Power Stage IC "BM3G0xxMUV-LB", which integrates the gate driver and GaN HEMT, and can easily replace Si MOSFETs.

ROHM names gallium nitride devices that contribute to the energy saving and miniaturization of application products as the "EcoGaN™ Family (ROHM trademark)" and is constantly working to further improve the performance of the devices. The EcoGaN™ Power Stage IC "BM3G0xxMUV-LB" replaces the existing Si MOSFETs, resulting in a 99% reduction in device volume and a 55% reduction in power loss, which is very helpful in reducing the size or loss of servers and AC adapters. "Zhou Jin, deputy general manager of Rohm Semiconductor (Shanghai) Co., Ltd. technology center, said at the recent media exchange and product launch conference.

It is understood that the starting time node of gallium nitride is roughly around 2020, the main application is focused on the fast charge of PCS and mobile phones, and then with the popularity of 5G and PD adapters, the market demand increases, and silicon devices alone can not meet the demand, so major semiconductor companies have begun to make efforts, and terminal manufacturers are also considering the use of DC-DC in the direction of electric vehicles or hybrid vehicles. In the future, with the increase in the application of electric vehicles and industrial systems, the market is expected to see greater growth after 2025.
Zhou Jin pointed out that although the application demand for gallium nitride devices will continue to expand, the use of gallium nitride usually faces two problems: first, the drive threshold voltage (Vth) is relatively low, usually about 1.5 to 1.8V, and there is noise when it is mistakenly turned on, which is not necessarily bad, but will lead to relatively high loss; Second, the grid voltage is relatively low, usually gallium nitride device calibration is 5V drive voltage, 4.5V below can be on but not completely, to 6V above the risk of grid damage. The optimal drive voltage range is narrow and the grid is difficult to handle. Gallium nitride devices usually work at very high frequencies, the noise and pulse situation are more complex, so it is easy to break, usually must be used with a special drive circuit or driver, but the number of external components will increase, in addition, the influence of channel parasitic parameters, at 200KHz or higher operating frequencies, will become more and more obvious.
In view of this, for industrial equipment such as data servers and consumer electronic equipment such as AC adapters, Romm has developed a new set of 650V Power Stage IC "BM3G0xxMUV-LB", the gate driver and GaN HEMT integrated package, can easily replace Si MOSFETs. The two maximize the performance of the FET, with Ga determining the efficiency value, and combine to achieve high-speed switching to more fully leverage the performance of gallium nitride devices.
Rohm's new product is VQFN package, 8×8mm, thickness is 1 mm IC, integrated package, drive voltage can achieve the same level as the current DC-DC controller, start time is also greatly reduced, transmission delay 11 nanoseconds to 15 nanoseconds, which is based on the high-speed characteristics of gallium nitride itself. Compared with ordinary products, the switching loss is low, the peripheral circuit is simpler, and only one external device is needed, which contributes to the miniaturization of application products. In addition, when using this Power Stage IC, the switching loss is significantly reduced compared to the Si MOSFET, and the device volume is significantly reduced compared to the Si MOSFET+ heat sink.

The grid driver has a voltage range interface built in, through which the original very narrow drive voltage requirements can reach 5V to 30V, Rohm plays on the technical advantages in analog, and adds it to the Power GaN series, which enriches the product lineup. In this chip will also have some EMI control, although high-speed circuit EMI is more difficult to control, so it is strengthened to optimize the drive waveform, without affecting the speed, can control EMI technology, as well as the corresponding power supply, temperature protection and other circuit composition, can simply replace the gallium nitride device to the existing scheme. And there is no need to significantly adjust the drive voltage, do not worry about noise effects, simplify the design engineer's man-hours.
Overall, Rohm's new products have three main features: support for each primary power supply circuit, low power consumption and miniaturization. First, in terms of supporting a variety of primary power circuits, the drive range is wide, the start time is short, can be applied in a variety of AC-DC circuits, and the transmission delay time is short, basically do not have to consider the delay time, the design of the whole loop and so on will be easier. A variety of AC-DC including flyback we will use more, half bridge is this, staggered and totem can be used Power Stage IC. The second is to further reduce power consumption, in the case of little impact on conduction loss, compared with Si MOSFET monomer reduced by 55%, compared with ordinary products, it can still be reduced by about 20%. Third, application products can be further miniaturized. In terms of the number of components, the ordinary product is 9 related components, while the new product of Rohm further simplifies the driving mode, and the external Power Stage related components only need 1.

According to Rohm's plan, for the next generation of Power Stage IC products, quasi-vibration AC-DC+GaN devices are expected to be mass-produced in the first quarter of 2024, power factor improvement +GaN devices are also expected to be mass-produced in the first quarter of 2024, and half-bridge +GaN devices are expected to be mass-produced in the second quarter of 2024.