LCD Display Inverter

On June 16, 2021, Dalian General Holdings, a leading semiconductor component distributor dedicated to the Asia-Pacific market, announced that its subsidiary World Peace has launched a small-scale MOS Driver based on ON Semiconductor NCP51820 650V Hi-Low Side GaN MOS Driver. Industrial power supply solutions.

Figure 1 – The Display board of the small industrial power supply solution based on ON Semiconductor products launched by the United Nations General Assembly and World Peace

Gallium Nitride (GaN) is the closest device to an ideal semiconductor switch, which enables power conversion with very high efficiency and high power density. While GaN devices are more efficient than today’s silicon-based solutions, they can easily exceed the most stringent 80+ specifications for servers and cloud data centers or the EU Code of Conduct Tier 2 standard for USB PD external adapters. However, GaN devices are inferior to old silicon technology in some aspects. In order to take full advantage of the potential advantages of this technology, the external driver circuit must be matched with the GaN device during circuit design.

Figure 2 – A block diagram of a small-scale industrial power supply solution based on ON Semiconductor products launched by World Peace

GaN drivers are critical to performance, and keeping the drive voltage within the voltage maximum limit is not the only requirement for the driver. For fast switching, although GaN also has gate capacitance properties, power is dissipated in the effective series resistance of the gate and in the driver. Therefore, it is important to keep the voltage swing to a minimum. In theory, a GaN device can safely turn off at VGS=0, but in practice, the voltage applied directly to the gate is unlikely to be 0V for even the best gate drivers. Therefore, optimizing the layout is the key to success. When using ON Semiconductor’s NCP51820, it can match the gate drive circuit and facilitate product miniaturization when performing layout layout. Place GaN devices and drivers on the same side of the PCB, avoiding high current vias by using ground/return planes appropriately.

Figure 3 – Example layout using ON Semiconductor NCP51820

The NCP51820 high-speed gate driver used in this scheme can be used to meet the stringent driving enhancement mode (e-mode), high electron mobility transistor (HEMT) and gate injection transistor (GIT), gallium nitride (GaN) power switch Require. NCP51820 provides short and matched propagation delay through advanced technology, provides −3.5V to +650V (typ) common-mode voltage range for high-side driver, and −3.5V to +3.5V common-mode voltage range for low-side driver. . In addition, the device provides stable dV/dt operation of up to 200V/ns for both driver output poles in high-speed switching applications.

Core technical advantages:

Ÿ NCP51820: Provides important protection features such as independent under-voltage lockout (UVLO), monitoring of VDD bias voltage, VDDH and VDDL driver bias, and thermal shutdown based on device die junction temperature. And the circuit actively adjusts the driver’s bias rail to prevent potential gate-source overvoltage under various operating conditions.

Ÿ NCP1616: The NCP1616 is a high voltage PFC controller designed to drive a PFC boost stage based on an innovative Current Controlled Frequency Foldback (CCFF) method. In this mode, the circuit will operate in critical conduction mode (CrM) when the Inductor current exceeds a programmable value. When the current is below this preset level, the NCP1616 linearly attenuates the frequency at a sinusoidal zero-crossing to a minimum of about 26KHz. CCFF maximizes efficiency at rated and light loads. Packaged in a SOIC-9 package, the NCP1616 has the features required in a rugged, compact PFC stage.

Ÿ NCP13992: It is a high-performance current-mode controller for half-bridge resonant converters. The controller implements a 600V gate driver, simplifying circuit layout and reducing external component count. In applications that require a PFC pre-stage, the NCP13992 detects the pin of the PFC Vbulk voltage, which can control the IC to work within a specific voltage range. Brown-out protection is triggered when the voltage change exceeds the setting. During no-load operation, the NCP13992 has a method for sharing a resistor divider with the PFC and LLC, sharing a large-capacity resistor divider to further reduce no-load power loss. The NCP13992 provides a range of protection features for safe operation in any application.

Program Specifications:

Ÿ Input power: 90–265V;

Ÿ Output power: 19V/18Amax (RMS);

Ÿ Efficiency: 95%Load (230Vac), 0%Load