EPC and Richtek introduce a reference design that achieves greater than 98% efficiency using the RT6190 buck boost controller and EPC2204 EPC GaN FETs

EL SEGUNDO, Calif.—  January 2023 — EPC & Richtek announces the availability of a 4-switches bidirectional buck-boost controller reference design board that converts an input voltage of 12 V - 24 V to a regulated 5 V - 20 V output voltage and delivers up to 5 A continuous current and 6.5 A 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 20 V and 12 V output voltage and can operate without heatsink with maximum rise temperature below 15 degC for 20 V to 5 V, and 55 degC for 12 V to 20 V, at 5 A continuous current.

The high-power density makes this solution ideal for buck boost converters with input 4 V-36 V and output 3 V-36 V like the ones used for 5 V-36 V battery chargers, battery stabilizers to 5 V – 36V and USB PD 3.1 charging (5 V, 20 V, 28 V, 36 V 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 100 V enhancement-mode EPC 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 4 V and 36 V and the output voltage is programmable between 3 V and 36 V and supports dynamic voltage scaling. The switching frequency reaches up to 1 MHz 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, 5 mm by 5 mm.

• The EPC2204 is a 100 V GaN FET with 6 mOhm max R_DS(on), 5.7 nC Q_G, 0.8 nC Q_GD, 1.8nC Q_GS and zero Q_RR in a super small 2.5 mm x 1.5 mm footprint and can deliver up to 29 A continuous current and 125 A peak current. The excellent dynamic parameters allow very small switching losses at 500 kHz – 1 MHz 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 R