High Isolation DC/DC Converters for Gate Drivers

DC/DC converters are often required to provide an isolated asymmetric supply for high-side gate drivers. The simplest (functional) isolation can withstand 1kVDC for one second. This sounds impressive; however this is often not sufficient.

High side inverters are often floated a few hundred volts with an opto-isolated PWM control, so the gate drivers need an isolated power supply. This isolated supply is typically +15/-9V for IGBT, +20/-5V or +15/-3V for SiC or +6V and +9V for GaN. A typical DC/DC isolation voltage would be at least twice the working voltage, but the high ambient temperature and fast switching edges generated by these high-power transistors additionally stress the insulation barrier. RECOM combines the required asymmetric output voltages, high insulation voltage and low isolation capacitance into one simple DC/DC converter module. Whether IGBT, SiC MOSFET or GaN HEMT, RECOM has the matching drop-in product.

High isolation 2W DC/DC converters for SiC gate drivers

Recom’s 2W (RKZ and RxxP2xx series) SiC gate driver DC/DC converters provide isolation up to 6.4kVDC/1 sec. They were specifically designed to power gate drivers for SiC MOSFETs requiring +20/-5V or +15/-3V drive levels.

Item Nominal Input Voltage (V) Output Voltage (V) Output Power (W) Isolation (kV)
R05P22005D/P 5 20/-5 2 6.4
R12P21503D 12 15/-3 2 6.4
R12P22005D 12 20/-5 2 6.4
R12P22005D/P 12 20/-5 2 6.4
R15P21503D 15 15/-3 2 6.4
R15P22005D 15 20/-5 2 6.4
R15P22005D/P 15 20/-5 2 6.4
R24P21503D 24 15/-3 2 6.4
R24P21503D/P 24 15/-3 2 6.4
R24P22005D 24 20/-5 2 6.4
R24P22005D/P 24 20/-5 2 6.4
RKZ-052005D 5 20/-5 2 3
RKZ-052005D/H 5 20/-5 2 4
RKZ-052005D/HP 5 20/-5 2 4
RKZ-052005D/P 5 20/-5 2 3
RKZ-122005D 12 20/-5 2 3
RKZ-122005D/H 12 20/-5 2 4
RKZ-122005D/HP 12 20/-5 2 4
RKZ-122005D/P 12 20/-5 2 3
RKZ-152005D 15 20/-5 2 3
RKZ-152005D/H 15 20/-5 2 4
RKZ-152005D/HP 15 20/-5 2 4
RKZ-152005D/P 15 20/-5 2 3
RKZ-242005D 24 20/-5 2 3
RKZ-242005D/H 24 20/-5 2 4
RKZ-242005D/HP 24 20/-5 2 4
RKZ-242005D/P 24 20/-5 2 3

DC/DC supplies for GaN technology

GaN devices are set to supersede existing SiC MOSFETs for many applications and reach their optimal performance with a gate switching voltage of +6V from RP-xx06S and RxxP06S DC/DC converter series. In GaN applications where higher noise and interferences have to be considered, RECOM also offers converters with +9V output which can be split up via a Zener diode to +6V and -3V to provide a negative gate voltage on turn-off ensuring that the gate voltage stays below the turn-on threshold.

Item Nominal Input Voltage (V) Output Voltage (V) Output Power (W) Isolation (kV)
R05P06S 5 6 1 6.4
R12P06S 12 6 1 6.4
R15P06S 15 6 1 6.4
R24P06S 24 6 1 6.4
RP-0506S 5 6 1 5.2
RP-1206S 12 6 1 5.2
RP-1506S 15 6 1 5.2