Transform’s new TDTTP4000W065AN rating board is now available and features the latest SuperGaN ™ Gen IV GaN technology to convert single-phase AC into 4 kW DC power, along with PFC with conventional analog control. In addition to providing an efficiency level higher than 99%, GaN technology ensures the required performance according to the datasheet without developing any firmware control software as is the case with solutions with Digital Signal Controllers (DSC). In an interview with EE Times, Philip Zuk VP of Global Art Marketing and Sales of NA, Transphorm, said that this board will reach over 99% efficiency with a high input (230V) similar to a digital solution. The evaluation suite offers a GaN-based platform, thus providing reliability of wide bandgap semiconductor physics and ensuring ease of design leadership and high volume repeatability (RDDR). The efficiency, as the Transphorm highlights, provide designers with a more efficient power supply system than standard CCM Boost PFC designs using superconducting MOSFETs. PFC topology circuits are used for bridging totemic power factor correction (PFC) for AC-DC conversion and include a two-wave bridge rectifier and a boost circuit. The input voltage on the bridge is reduced and the boost phase determines the quality of the system’s efficiency. The non-bridging PFC totemic switch shows the smallest conduction loss between all non-bridging PFC topologies and requires the fewest components. Efficiency is obtained by removing the high-voltage diode bridge rectifier and using the bidirectional current flow capacity provided by GaN through constant-switch synchronous rectification and either single phase or staggered control methods. Transphorm has examined a family of bridgeless PFC switches, including Dual Boost Bridgeless PFCs, two PFC bridging booster circuits, a Bridgeless Bidirectional PFC, and a Totem-pole bridgeless PFC for diode bridge de-insertion. With a typically two-chip GaN FET solution using a low-voltage silicon MOSFET and a GaN HEMT depletion mode, the solution provides low additional switching losses, low Qrr, and low capacitance. This allows simple and efficient power transmission circuits. Figure 1: PFC boost converter without bridged electrode based on GaN HEMT (a) line correction diode (b) MOSFET for line correction (source: Transphorm) Figure 1: PFC batch converter without bridges based on GaN HEMT (a) diode (B) Line correction MOSFET for line correction (Source: Transphorm) Figure 1 shows a non-bridging PFC converter with GaN HEMT in two configurations. The configuration shown in Fig.1b increases the efficiency by replacing the diodes shown in Fig.1a with two MOSFETs. Figure 2: The principle of operation of a PFC without a bridge (a) a positive half-cycle (b) a half-cycle negative (source: Transphorm) The operating principle of a PFC totem pole is shown in Figure 2. In the positive half-cycle of an AC line, D2 leads and connects the AC signal to ground Output. S2 is the active booster switch and S1 releases the inductance current and discharges the power of the inductor to drive the output. The S1 will be complementary to ignition in harmony with the inductor to reduce conduction losses. In the negative half cycle, D1 connects and connects the AC source to the DC output bus. S1 is the active booster switch and S2 fires the inductor current. The operation mode changes with each cycle. In the positive half, the PWM determined by the boost load ratio makes the switch S2, while in the negative half it performs the switch S1. The operation of the MOSFET release is the same, except that the MOSFET is actively energized for straight line in half a turn. GaN Panel Rating The 4 kW (180-260V) and 2kW (90-120V) high line rating kit does not require any DSP firmware programming, thus adapting to standard AC-to-DC augmented CCM power phases . “Electronic power engineers have always used enhanced CCM / CRM switches for analog control. In order to use a digital totem pole, firmware development is required. Many Tier 2/3/4 power supply companies have neither this capability nor the resource (s), so We enable them with the analog solution. They can access high performance PFC with analog control solution without any firmware required. Fast time to market … The analog board helps designs to reach the market faster. It’s also a great starting point for a digital solution if they want Move in this direction in the future.Finally, this solution also gives a direct competitor to the traditional push of PFC that uses silicon, ”Zuck said. Engineers who need more flexibility in the design process can use TDTTP4000W066C 4 kW board TDTTP4000W066C with dsPIC33CK preprogrammed microchip plus non-bridging PFC totem shaft for SuperGaN FETs in Transphorm. TDTTP4000W065AN uses SuperGaNTM Gen IV TP65H035G4WS SuperGaNTM FETs as fast switch support and with low resistance silicon MOSFETs and soft switch support. SuperGaNTM FETs can operate at a threshold voltage (Vth) of 4V and a standard turnkey gate driver operates from 0 to 12V. “This panel does not offer any customization like digital design. It gives the designer a direct alternative to the standard, as the silicon enhances the PFC with higher efficiency. This efficiency is due to a combination of our GaN platform and analog control. Maintenance or auxiliary power is basically constant regardless of power level System. Because the analog board does not use a DSP, its auxiliary power may be less dependent on the design of the circuit boards. This may result in slightly improved efficiency at lower forces as the extra power draw becomes a higher percentage of the total loss of the solution. This may in fact be an advantage. For the designer in determining whether our analog control solution is the preferred design option. However, as noted above, there are other variables to consider as well, Philip Zuck said. The TP65H035G4WS is a 650V device with 35mOhm resistance in the TO- package. 247 with an intrinsically high heat dissipation capacity providing the possibility of disposing of any additional device in parallel if more power is required.