Richtek and EPC collaborate on 140W fast charger
Reference design achieves greater than 98 percent efficiency using RT6190 buck boost controller and EPC GaN FETs
EPC and Richtek have announced the availability of a four-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.
They say that the combination of the new Richtek RT6190 controller with EPC2204 GaN FETs shrinks the size by greater than 20 percent compared to traditional solutions for high-power density applications. The solution achieves greater than 98 percent 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 suits the design to 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 stabilisers 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 RT6190 is a four – 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 RDS(on), 5.7 nC QG, 0.8 nC QGD, 1.8nC QGS and zero QRR in a 2.5 mm x 1.5 mm footprint and can deliver up to 29 A continuous current and 125 A peak current. The dynamic parameters allow very small switching losses at 500 kHz – 1 MHz switching frequency, especially in hard switching applications like buck boost converters.
