Dailian Youshang Group launched 250W LLC resonant DC converter development board based on ST products

May 19, 2022, United University Holdings, a leading semiconductor component distributor dedicated to the Asia Pacific market, announced that its subsidiary, Yushang, has launched a 250W LLC resonant DC converter development board based on ST MasterGaN1+L6599A chip.

With the continuous evolution of semiconductor and power electronics technology, people have higher and higher requirements for power products in terms of size, efficiency, reliability, life span and comfort.In this context, the traditional power supply technology has been difficult to meet the application requirements, so LLC resonance conversion technology to achieve high power switching efficiency is widely used.Based on ST MasterGaN1 and L6599A chip, Dailian Dayushang launched 250W LLC resonant DC converter development board scheme.This highly integrated solution helps customers improve power density and energy efficiency, simplify product design and shorten time to market.

This case is driven by MasterGaN1, MasterGaN1 is an integrated STDRIVE half-bridge gate driver and two 650V enhanced GaN transistor products, its maximum power up to 400W, the maximum rated current is 10A, and the low side and high side are undervoltage off protection,To prevent the power switch from working in inefficient or dangerous conditions.Moreover, MasterGaN1 also has built-in bootstrap diode and built-in interlock function, which can effectively avoid cross conduction conditions.And due to the excellent switching performance of GaN transistors, their operating frequency is higher than that of ordinary silicon-based MOSFET solutions, so smaller electromagnetic components and capacitors can be used to achieve higher power density and lower bill of material cost.

The L6599A in the scheme is a dual-terminal controller for the series resonant half-bridge topology.It provides a 50% complementary duty cycle in which the high voltage side switch and low voltage side switch are switched on/off in a 180° disphase manner at the same time.The output voltage regulation of the device is realized by adjusting the working frequency.To drive the high voltage side switch using a bootstrap method, the L6599A uses a high voltage floating structure capable of withstanding voltages above 600V and is equipped with a synchronous drive high voltage DMO.In terms of functionality, the L6599A integrates a non-latched low activation disable input and a current detection input for OCP, providing complete overload and short circuit protection.

In addition, the SRK2001 synchronous rectifier IC used in the scheme realizes the specific control of the secondary synchronous rectifier in the LLC resonant converter, ensuring that each synchronous rectifier is switched on when the corresponding half winding starts to turn on and disconnected when its current drops to zero.The on-logic with adaptive masking time and adaptive turn-off logic allows maximum on-time SR MOSFET, eliminating the need for parasitic inductor compensation circuits.

By combining the main performance of the device, the solution achieves a maximum energy efficiency of over 94%, and is suitable for applications with limited volume and space due to its high efficiency and small size.After testing, the output power of the development board can reach 250W at 24Vdc, and the nominal input voltage provided by the traditional front-end PFC is 400V.

Core technical advantages:

Using MarterGaN can reduce space by 4 times and weight by 3 times;

No need for radiator design;

DC input voltage: 400V±10%;

DC output voltage: 24V;

The output current can reach 10.4A;

The output power can reach 250W;

Applications in switching power supplies, chargers and adapters, industrial DC-DC applications, consumer SMPS.

Scheme specification:

Use MasterGaN1 efficient and compact DC/DC conversion solution;

Output voltage: 24V;

Output power up to 250W;

Nominal input voltage: 400 V+/-10%;

Efficiency: & gt;92%;

Prevent short circuit and over current output;

Input voltage monitor for correct sequencing and power off protection of D2D converters;

Circuit board size: 100 x 60 (W x H) mm, maximum component height: 35mm;

Comply with WEEE and RoHS standards;

Applications: Industrial DC-DC applications, adapters, consumer switching power supplies.