Richtek and EPC Collaborate to Create Small 140 Watt Fast-charging Solution

EPC & Richtek announces the availability of a 4-switches bidirectional buck-boost controller reference design board that converts an input voltage of 12V - 24V to a regulated 5V - 20V output voltage and delivers up to 5A continuous current and 6.5A maximum current. The combination of the new Richtek RT6190 controller with ultra-efficient EPC2204 GaN FETs from EPC shrinks the solution size by greater than 20% compared to traditional solutions for high-power density applications.  The solution achieves greater than 98% efficiency for 20V and 12V output voltage and can operate without heatsink with maximum rise temperature below 15 degC for 20V to 5V, and 55 degC for 12V to 20V, at 5A continuous current.

The high-power density makes this solution ideal for buck boost converters with input 4V-36V and output 3V-36V like the ones used for 5V-36V battery chargers, battery stabilizers to 5V – 36V and USB PD 3.1 charging (5V, 20V, 28V, 36V support). GaN FETs provide the fast switching, high efficiency and small size that can meet the stringent power density requirements of these leading-edge applications.

The reference design uses the EPC2204 100V enhancement-mode GaN FET and the RT6190 4-switches buck boost controller with integrated GaN drivers.

The RT6190 is a 4 – switches bidirectional buck boost controller with I²C interface using peak current mode control. The input voltage ranges between 4V and 36V and the output voltage is programmable between 3V and 36V and supports dynamic voltage scaling. The switching frequency reaches up to 1MHz for high power density and the device offers power saving mode for high light load efficiency. Output current, voltage and soft start can be precisely programmed, and the device is fully protected and offers OCP, UVLO, OVP, OTP, cycle by cycle current limit, and PGOOD in a tiny package, 5mm by 5mm.

The EPC2204 is a 100V GaN FET with 6 mOhm max R_DS(on), 5.7nC Q_G, 0.8nC Q_GD, 1.8nC Q_GS and zero Q_RR in a super small 2.5mm x 1.5mm footprint and can deliver up to 29A continuous current and 125A peak current. The excellent dynamic parameters allow very small switching losses at 500kHz – 1MHz switching frequency, especially in hard switching applications like buck boost converters. Higher switching frequency enable to reduce the inductor value, size, and DCR and the capacitor count for less losses and higher power density.

Alex Lidow, CEO of EPC commented, "GaN FETs are required to achieve the maxim power density for DC-DC converters. We are delighted to work with Richtek to combine the benefits of their advanced controllers with the performance of GaN to provide customers with the highest power density and low component count solution that increases the efficiency, increases power density, and reduces system cost".

"The Richtek Device's RT6190 is designed to fully exploit the high performance of EPC's eGaN FETs for high power density solutions" said by Eason Chen, ,Sr. Application Marketing Manager at Richtek, "The RT6190 offers higher switching frequency and integrates all protections feature and functionality required for 4-switches buck boost controller for battery chargers and battery management/stabilizers to a fixed voltage, very common for consumer USB applications for PC and smart phone, e-bike, e-scooter, battery-operated appliances and power tools, medical, industrial and solar applications. With these new controllers, customers can take advantage of the very fast switching of GaN for the highest power density.”