AC/DC Conversion Without Diodes

Introduction: Rethinking AC/DC Conversion Without Diodes

Traditional AC/DC converters rely on diode bridges to rectify AC into DC, but diodes inevitably introduce a forward voltage drop (typically ~0.7 V for silicon or ~0.2–0.5 V for Schottky devices). This causes power loss as heat and limits efficiency. In high-current or low-voltage applications, the diode losses become significant – for example, a standard bridge rectifier can consume 2–3% of output power at low AC line voltages (A comparative analysis of topologies for a bridgeless-boost PFC circuit). To achieve near-lossless rectification, engineers are exploring alternatives that eliminate or drastically reduce these forward-drop losses. Modern approaches replace passive diodes with active switching devices (like MOSFETs or other semiconductors) and clever circuit topologies to allow current flow in one direction with minimal resistance. In this answer, we’ll explore several such methods – from synchronous rectifier circuits and advanced power electronics topologies to emerging technologies (wide-bandgap semiconductors, superconducting diodes, etc.) – and discuss their efficiency, feasibility, and real-world adoption.

Synchronous Rectifiers and “Ideal” Diodes

One widely used approach is synchronous rectification, in which diodes are replaced by actively controlled MOSFET transistors that act as near-ideal one-way valves. A MOSFET, when fully enhanced, can have an on-resistance of only a few milliohms, dropping only a few millivolts under load – much smaller than a diode’s fixed drop (AC to DC conversion without using diodes and no external supply). In a synchronous rectifier, the MOSFET is turned on during the portion of the AC cycle when current should flow (mimicking the diode’s conducting state) and turned off when current would reverse. This yields dramatically lower conduction loss. In practice, active diode controller ICs (e.g. the LT4320 ideal bridge controller or TI’s ideal diode controllers) monitor the voltage across a MOSFET and drive its gate to act like an ideal diode, automatically turning it on when forward-biased and off when reverse-biased. A power p-channel MOSFET tied with its gate to ground can thus function as a diode with only a few mV drop (AC to DC conversion without using diodes and no external supply), and more sophisticated gate-drive chips use n-channel MOSFETs for even lower RDS(on). Synchronous rectification is commonplace in modern DC power supplies – for example, on the low-voltage output of switching regulators or in OR-ing circuits for redundant supplies – because it improves efficiency by 2–3% over diode rectifiers across a range of loads (Synchronous Rectifiers Improve Efficiency - DigiKey). This is especially crucial in high-current, low-voltage scenarios (such as VRMs for CPUs or battery chargers), where diode losses would waste substantial power as heat. Commercial controller ICs (like Linear Technology’s LT4320 and LT8672, or Microchip’s IdealBridge series) make it relatively easy to implement “ideal” full-bridge rectifiers using MOSFETs, and these have been adopted in applications from automotive power systems to Power-over-Ethernet (PoE) bridges.

Active rectification can be scaled to larger systems as well. For instance, researchers and industry have applied synchronous MOSFET rectifiers to AC alternators in vehicles to replace the six diode pack. By actively controlling MOSFETs in sync with the alternator phases, the voltage drop at ~100+ A currents is greatly reduced, improving the alternator’s efficiency. One design demonstrated a 12 V automotive alternator with a six-phase winding and a MOSFET-based active rectifier, handling up to 120 A with much lower losses than diodes (A smart synchronous rectifier for 12 V automobile alternators). The obvious trade-off is added complexity: active rectifiers require sensing and control (sometimes using small microcontrollers or analog driver circuits) to time the transistor gating. Nonetheless, the feasibility is high – many off-the-shelf solutions exist, and synchronous rectifiers are already ubiquitous in laptop chargers, ATX power supplies, and energy-harvesting interfaces. The cost and control overhead are justified by the efficiency gain and reduced heat dissipation (which can eliminate bulky heatsinks (LT4320 Ideal Diode Bridge Controllers Subverts the Traditional Bridge Rectifier - Ventron)). Overall, synchronous rectification using MOSFETs is a proven, commercially available technique for near-lossless AC/DC conversion, achieving forward drops on the order of tens of millivolts and greatly improving efficiency.

Bridgeless and Active Switching Topologies

Beyond one-for-one diode replacements, power engineers have developed new AC/DC converter topologies that eliminate the traditional diode bridge altogether. The front-end diode bridge in an AC mains rectifier not only incurs conduction loss, but also constrains the topology to unidirectional power flow. By using active switches (transistors) in place of diodes in the AC input stage, one can create a bridgeless rectifier that reduces the number of series drops and can actively control the input currents. A prime example is the totem-pole bridgeless PFC (Power Factor Correction) circuit. In a totem-pole PFC, the rectifier is formed by a half-bridge of transistors that alternately conducts on the positive and negative half-cycles, combined with a boost inductor. This arrangement eliminates the four-diode bridge; at any given time, current flows through only two semiconductor switches (one high-frequency transistor and one low-frequency conduction device) instead of through two diodes plus a transistor as in a conventional boost PFC (Bridgeless totem-pole PFC converter. | Download Scientific Diagram) (Bridgeless totem-pole PFC converter. | Download Scientific Diagram). By removing one or more diode drops from the line current path, bridgeless PFC can improve efficiency by roughly the voltage drop of one diode (about 0.7 V) – a non-trivial gain in low-line conditions (A comparative analysis of topologies for a bridgeless-boost PFC circuit). Texas Instruments notes that substituting a bridgeless design for a standard diode bridge can save those ~2% losses and help meet the stringent 80 Plus Platinum/Titanium efficiency standards for PSUs ().

Early bridgeless PFC implementations (often called dual-boost PFC) still used diodes in parts of the circuit (like using the MOSFET’s body diode during alternate half-cycles (A comparative analysis of topologies for a bridgeless-boost PFC circuit)). However, the most advanced incarnation is the continuous-conduction totem-pole PFC which uses two transistors switching at high frequency and two transistors (or sometimes diodes) at line frequency to steer the AC polarity. When implemented with suitable devices, the totem-pole topology allows only one active switch and one low-loss switch to conduct at any given time, with no diode in series (The totem-pole power factor correction (PFC) rectifier in energy... | Download Scientific Diagram). The challenge here is managing the AC zero-crossing: if using conventional silicon MOSFETs, the slow recovery of their body diodes would cause large current spikes when the current reverses direction (98.6% Efficiency, 6.6-kW Totem-Pole PFC Ref Design for HEV/EV Onboard Charger (Rev. B)). This is where modern semiconductor technology comes in (discussed more below): using wide-bandgap devices like GaN HEMTs or SiC MOSFETs, which have negligible reverse-recovery charge, engineers have made totem-pole PFC practical at high power and high frequency (98.6% Efficiency, 6.6-kW Totem-Pole PFC Ref Design for HEV/EV Onboard Charger (Rev. B)). The result is AC/DC rectifiers with astonishing efficiency – 99%+ peak efficiency has been demonstrated in several designs using these methods () (CRD-03600AD065E-L 3.6kW Bridgeless Totem-Pole PFC Reference Design | Wolfspeed). For example, a 3.6 kW totem-pole PFC reference design with SiC MOSFETs achieved ~99% peak efficiency, targeting 80Plus Titanium requirements (CRD-03600AD065E-L 3.6kW Bridgeless Totem-Pole PFC Reference Design | Wolfspeed) (CRD-03600AD065E-L 3.6kW Bridgeless Totem-Pole PFC Reference Design | Wolfspeed). Similarly, a 6.6 kW totem-pole PFC for an EV onboard charger reached 98.6% efficiency in practice (98.6% Efficiency, 6.6-kW Totem-Pole PFC Ref Design for HEV/EV Onboard Charger (Rev. B)) (98.6% Efficiency, 6.6-kW Totem-Pole PFC Ref Design for HEV/EV Onboard Charger (Rev. B)) – far above what an all-diode approach could manage.

Active rectifier front-ends also bring other benefits: they can be made bidirectional, enabling energy to flow back into the AC line when desired. This is essentially an Active Front End (AFE) rectifier – a full bridge of transistors that can rectify with near-unity power factor and also invert DC back to AC. Industrial variable-speed drives and regenerative braking systems use AFE rectifiers in place of diode bridges so that returned energy can be fed into the grid and input current harmonics are minimized ( Advantages of both Diode Front End and Active Front End rectifiers ) ( Advantages of both Diode Front End and Active Front End rectifiers ). While AFEs still incur switching and conduction losses in their transistors, they avoid fixed diode drops and can be controlled for optimal efficiency and power quality. For three-phase systems, specialized topologies like the Vienna rectifier use a combination of three active switches and three diodes to achieve a mid-point rectification with reduced losses. A well-designed three-phase PWM rectifier (Vienna or full six-switch) can exceed 99% efficiency as reported in research (Design and implementation of interleaved Vienna rectifier with ...), thanks to sharing the load across phases and using synchronous techniques. The Vienna rectifier, for instance, eliminates one diode drop per phase and is commonly used in high-efficiency EV chargers and server supplies.

In summary, bridgeless and active rectifier topologies remove the inherent loss of a diode bridge by using coordinated switching. These require careful control (often a digital controller or DSP to generate PWM gating signals) and often the use of advanced semiconductors to manage switching transients. They are more complex and sometimes require additional EMI filtering or inrush current management (since the neutral or line may no longer be at a fixed potential through diodes). Despite this, such topologies are already moving from labs into products. For instance, GaN-based totem-pole PFC circuits are now found in some ultra-efficient PC power supplies and laptop adapters. The feasibility is evidenced by evaluation kits from major vendors – e.g. Infineon, TI, GaN Systems, and Wolfspeed all offer reference designs showing >98–99% efficient AC/DC converters using no input diodes.

Advanced Semiconductor Devices Enabling Low-Loss Rectification

Key to many of the above improvements is the availability of better switching devices than the classic silicon diode. Advanced semiconductor devices are making “almost lossless” rectification a reality. Two major classes are worth noting: wide-bandgap (WBG) power semiconductors (like SiC and GaN), and improved diode structures (Schottky and beyond).

• SiC (Silicon Carbide) and GaN Transistors: These have revolutionized high-power rectifiers. SiC Schottky diodes were an early game-changer – they have no significant reverse recovery, so they dissipate far less during switching and can operate at high frequency without the large current spikes of silicon PN diodes. Now, SiC MOSFETs and GaN HEMTs allow the rectifier function to be performed by transistors with extremely low loss in both conduction and switching. GaN FETs, in particular, have an advantage of virtually zero stored charge when reversing bias (Qrr ≈ 0) (Review of GaN Totem-Pole Bridgeless PFC - IEEE Xplore). This means a GaN transistor can act as an AC rectifier switch that turns off cleanly each half-cycle with no reverse current overshoot – something not possible with a silicon MOSFET’s body diode. In the totem-pole PFC context, GaN FETs eliminated the slow diode problem, enabling continuous conduction mode operation with very high efficiency (Review of GaN Totem-Pole Bridgeless PFC - IEEE Xplore). SiC MOSFETs similarly have much lower reverse recovery than silicon, and also lower on-resistance at high blocking voltages, making them ideal for high-power active rectifiers (like EV chargers running off 240 VAC). The use of WBG devices thus directly improves rectifier efficiency by reducing both conduction drop and switching loss. One report cites that replacing a traditional diode bridge plus boost PFC with a GaN totem-pole design allowed the PFC stage to reach >98.5% efficiency (), whereas conventional silicon solutions would struggle to hit 97%. Commercially, GaN and SiC parts are available and increasingly cost-effective, so many new AC/DC designs (from 150 W up to multi-kW) are leveraging them.

• “Ideal diode” ICs and integrated devices: In addition to discrete MOSFETs, there are now integrated devices specifically for rectification. For example, Microchip’s PD70224 IdealBridge is a dual MOSFET bridge rectifier intended for PoE applications, with internal low-RDS(on) FETs and control circuitry that can replace diode bridges at up to around 1 A, dramatically improving efficiency in power-over-Ethernet powered devices. Likewise, Analog Devices (Linear Tech) offers chips like LT8672/LT8650 family that drive external MOSFETs as ideal diodes for automotive alternator outputs and battery chargers (to reduce the heat in OR-ing diodes or rectifiers). These advanced components embody the concept of near-lossless rectification in convenient form – for instance, the LT4320 controller mentioned earlier can drive four N-channel MOSFETs in a full-bridge, eliminating the two diode drops and improving available output voltage and thermal performance in low-voltage AC/DC systems (LT4320 Ideal Diode Bridge Controllers Subverts the Traditional Bridge Rectifier - Ventron). Even for three-phase AC, one can use multiple chips (Analog Devices has application notes for three-phase MOSFET bridges) to maintain low losses across all phases (LT4320 Ideal Diode Bridge Controllers Subverts the Traditional Bridge Rectifier - Ventron). In short, the semiconductor industry is actively delivering components to make diode-free rectifiers easier to implement.

• Schottky and Low-Voltage Drop Diodes: It’s worth noting that not all rectifier improvements require active control; material science has also improved passive diodes. For example, at low currents, Schottky barrier diodes (made of silicon, or now SiC for higher voltages) have lower forward drops than PN diodes and negligible reverse recovery. A SiC Schottky diode might drop ~0.3–0.4 V at moderate currents (and less at lower currents), versus ~0.7–1 V for a silicon diode, thereby reducing losses. These are commonly used in PFC circuits and SMPS outputs when active MOSFET rectification is not feasible. There is also research into novel diode structures (e.g. merged PiN Schottky diodes, or use of gallium nitride diodes) that further push down forward voltage. However, no matter how good a diode gets, it can’t beat the near-zero I·R drop of a turned-on transistor. Thus, the trajectory is clearly toward actively switched devices for rectification whenever ultra-high efficiency is needed.

In summary, advanced devices like GaN FETs and SiC MOSFETs are enablers that make “lossless” rectifier topologies possible at high power, and integrated ideal-diode controllers make them practical at lower power. These technologies are commercially available and continually improving, which is why we now see AC/DC converter efficiencies creeping toward the 99% mark using diode-less designs.

Emerging Technologies and Experimental Approaches

Looking further ahead, there are fascinating developments aiming for truly lossless rectification and novel ways to convert AC to DC:

• Superconducting Rectifiers: One cutting-edge concept is using superconductors to create a diode effect with zero resistance. A superconducting material normally carries current with no loss in either direction. But researchers have demonstrated the “superconducting diode effect”, where a device made of layered superconductors and ferromagnets passes current freely in one direction while blocking it in the opposite direction (Highly Efficient Superconducting Diodes and Rectifiers for Quantum Circuitry) (Highly Efficient Superconducting Diodes and Rectifiers for Quantum Circuitry). Essentially, this creates a diode-like behavior without normal-state resistance – the forward current is dissipationless (until you exceed a critical current) and reverse current is suppressed. A recent experiment built a full-wave rectifier bridge out of such superconducting diodes (using V/EuS thin-film junctions) and successfully converted AC to DC at frequencies up to 40 kHz (Highly Efficient Superconducting Diodes and Rectifiers for Quantum Circuitry). The efficiency in that early test was only ~43% (Highly Efficient Superconducting Diodes and Rectifiers for Quantum Circuitry) (since the superconducting state could be partially compromised during switching), but it proved the concept of a zero-resistance rectifier. If this technology matures, one could imagine ultra-efficient AC/DC conversion in cryogenic systems – for example, feeding DC bias currents in superconducting quantum computing or MRI systems with no Joule heating. Of course, the need for cryogenic cooling means this isn’t a general solution for everyday electronics, but it’s an exciting research frontier for niche applications where even the smallest losses are intolerable or where the entire system already operates at low temperature.

• Graphene and High-Frequency “Diodes”: At the opposite end of the scale (microscale and high frequency), there is work on novel rectifiers for RF and terahertz energy. One example is the graphene geometric diode – a tiny planar diode that relies on the geometry of a narrow channel to enforce one-way current flow in a material with no bandgap. Graphene’s extremely high carrier mobility allows these devices to rectify very high-frequency AC (in the THz range) at zero or very low bias () (). In essence, these are diode-like devices without a traditional semiconductor junction – they achieve rectification through ballistic transport or field effects rather than a PN junction’s built-in potential. Research has demonstrated graphene diode bridges that can perform full-wave rectification, albeit at small signal levels, with operation well into the terahertz frequencies () (). The motivation here is to enable efficient “rectennas” – rectifying antennas – for wireless power transfer or energy harvesting from ambient RF, microwaves, or even infrared light. Traditional diodes struggle to rectify very high-frequency electromagnetic waves due to capacitance and switching losses. A device like a graphene diode or a tunneling diode (e.g. metal-insulator-metal diode) can potentially convert, say, a 2.4 GHz or 10 THz wave into DC with minimal loss. While these are far from handling mains power, they represent emerging rectification technology in domains like IoT energy harvesting, contactless power, and even thermal energy rectification (turning heat radiation into DC electricity). In summary, quantum and nano-scale rectifiers are being explored to push rectification into frequency regimes and efficiency levels unattainable by conventional diodes. They might not replace power diodes in your phone charger, but they could enable new types of very high frequency AC/DC conversion that border on “direct energy conversion” (for example, converting sunlight or waste heat to DC via antenna and diode).

• Resonant and Mechanical Rectifiers: Another category of alternative AC/DC conversion uses neither diodes nor continuously driven transistors, but cleverly timed circuit elements. In some energy-harvesting circuits (like piezoelectric harvesters), researchers use synchronized switching techniques (e.g. SSHI – synchronized switch harvesting on inductor) which effectively flip the voltage at peak strain to emulate a rectification and energy extraction without a diode drop. These circuits often use small MOSFETs or MEMS switches that briefly connect inductors or capacitors at the right moments, achieving a voltage inversion that results in DC output. While these still use semiconductors, they are not diodes – they are lossless in the sense that the switching ideally occurs when current is zero (resonant timing), so the energy loss is minimal. There are also mechanical rectifiers: for example, a homopolar motor-generator or a commutator in a DC generator is effectively a mechanical AC-to-DC converter. Early 20th-century high-voltage DC systems even used mercury-arc rectifiers and motor-generator sets to convert AC to DC before power semiconductors existed. Those methods avoided semiconductor diode drops (since they predate semiconductor diodes), but of course introduced other losses (friction, plasma voltage drops, etc.), so they are largely historical curiosities now. Still, it’s interesting that the commutator of a DC dynamo is a mechanical analog of synchronous rectification – brushes physically switch the connections in sync with the AC in the armature to output unidirectional current, a process that can be quite efficient (90%+ in large machines, albeit with maintenance and sparking issues).

In summary, emerging technologies aim either to remove the resistive element entirely (as with superconducting diodes) or to push rectification into new realms (ultra-high frequency, ultra-low voltage) where traditional diodes don’t work well. Most of these are experimental, but they highlight the ongoing innovation toward lossless rectification.

Efficiency, Feasibility, and Applications

How close are we to “lossless” AC/DC conversion, and where are these methods being used? Today’s state-of-the-art rectifiers, using the techniques described, can achieve on the order of 99% efficiency at medium to high power. For instance, totem-pole PFC front-ends paired with synchronous DC-DC stages enable Titanium-grade server power supplies – delivering, say, 1–3 kW at 98–99% efficiency () (CRD-03600AD065E-L 3.6kW Bridgeless Totem-Pole PFC Reference Design | Wolfspeed). This means only a percentage point or two of the power is lost as heat, an astonishing improvement over older designs that might lose 5–10%. Such high efficiency significantly cuts energy waste and eases thermal management. Data centers and telecom operators are keen adopters, since even small efficiency gains translate to huge energy savings (and easier cooling) when multiplied over thousands of units. We are also seeing these techniques in electric vehicle chargers and solar inverters. EV onboard chargers must convert AC to DC to charge the battery, and using active rectifiers (often with SiC devices) allows them to reach high efficiency and even feed power back to the grid (for vehicle-to-grid features). Renewable energy systems (wind turbines, grid-tie solar inverters) also often use controlled rectifiers to handle the AC from generators or to draw AC from the grid with unity power factor and low loss.

On the lower end of power, virtually all modern phone and laptop chargers use synchronous rectifiers on their high-frequency transformer outputs, which is why these adapters are both compact and efficient. For mains rectification in these small devices, some still use diode bridges (due to cost and simplicity), but as silicon area and control become cheaper, even small power supplies are starting to adopt bridgeless or semi-bridgeless input stages to meet efficiency regulations. There are demonstration ICs of active bridge driver chips that work at 50–60 Hz mains (one example is the STMicroelectronics SRK1000 series intended to drive MOSFETs in place of input diodes). These chips sense the AC waveform and appropriately turn on two MOSFETs at a time in a full bridge, effectively making an “ideal diode bridge” for mains. When such technology becomes cost-competitive, wall warts and LED drivers could eliminate their ~1.4 V bridge drop and gain a couple percentage points in efficiency.

In specialized arenas, energy harvesting circuits already extensively use active rectification. For example, devices that convert ambient vibrations or RF signals to DC often employ active rectifier circuits because the input voltages can be extremely low (tens of millivolts). A good example is a thermal energy harvesting IC like Linear Technology’s LTC3109, which can harvest from a thermoelectric generator with as little as 20 mV output. It uses an internal resonant boost converter that alternately flips the connections to step up and rectify even tiny AC voltages without diodes (since a diode drop would outright block a 20 mV source). These kinds of circuits make it possible to charge sensors from small temperature differences or RF fields, which would be impossible with ordinary diodes.

In terms of commercial availability, most of the techniques discussed are either already productized or rapidly moving in that direction. Synchronous rectifier MOSFETs and controller ICs are commodity components in power electronics. GaN and SiC transistors are now mass-produced and used in consumer products (for example, GaN Fast chargers). Bridgeless PFC designs are referenceable from major semiconductor firms (TI, Infineon, NXP, etc.), and digital control ICs for them are on the market. Active front-end drives are offered by manufacturers like ABB, Schneider, etc., for industrial use. The more exotic solutions – superconducting diodes, graphene rectifiers – are still in the research or prototype phase and not commercially used in power conversion (it will likely be a while before we see a “superconducting rectifier module” on Digi-Key, if ever). Nonetheless, the research shows a clear trend: minimize or eliminate the diode’s role in order to approach ideal efficiency.

Efficiency vs. complexity is always a consideration. Each of these diode-less methods tends to add complexity: extra control circuitry, gate drivers, sometimes sensing elements or even microcontrollers, which can slightly reduce reliability or increase cost. However, as technology matures, these complexities are being integrated and cost-reduced. For instance, where once you’d need a small MCU to control a synchronous rectifier, now a cheap dedicated IC can do it. In high-volume applications, the efficiency gains (which allow smaller heatsinks, smaller enclosures, or higher power density) often outweigh the added component cost. From a feasibility standpoint, there is little doubt that active rectification is the future for most applications, except perhaps the very simplest or lowest-power ones where a diode’s loss is negligible.

In conclusion, engineers have devised a host of alternatives to the plain diode rectifier – from MOSFET-based synchronous rectifiers and clever bridgeless PFC circuits to advanced semiconductor devices and even superconducting and quantum-effect rectifiers. These innovations are driving rectifier losses toward zero. Many of these methods are already in practical use, delivering significantly higher efficiency and enabling new functionality (like bidirectional power flow). As efficiency standards and energy awareness continue to rise, we can expect “lossless” rectification techniques to become standard in everything from phone chargers to megawatt converters, squeezing out the last few percentage points of waste that diodes used to dissipate as heat. The age of the purely passive diode rectifier is slowly giving way to actively switched, intelligently controlled AC/DC conversion – bringing us ever closer to the ideal of a lossless rectifier.

Sources:

• Texas Instruments – Bridgeless PFC topology eliminates diode bridge losses (A comparative analysis of topologies for a bridgeless-boost PFC circuit) ()
• GaN Systems – Totem-pole PFC efficiency results (99%+ achievable by eliminating diodes) () ()
• Wolfspeed – 3.6 kW SiC active rectifier achieves 99% efficiency (for Titanium-grade PSU) (CRD-03600AD065E-L 3.6kW Bridgeless Totem-Pole PFC Reference Design | Wolfspeed) (CRD-03600AD065E-L 3.6kW Bridgeless Totem-Pole PFC Reference Design | Wolfspeed)
• Do et al., Energy Storage Systems Totem-Pole PFC design (use of MOSFETs instead of diodes to improve efficiency) (The totem-pole power factor correction (PFC) rectifier in energy... | Download Scientific Diagram)
• AllAboutCircuits forum – Using MOSFET as diode (few mV drop) in AC rectifier (AC to DC conversion without using diodes and no external supply)
• Digi-Key article – Synchronous rectification yields ~2–3% efficiency gain over diodes (Synchronous Rectifiers Improve Efficiency - DigiKey)
• Ingeteam Active Front End guide – Active rectification replaces diodes with switches, allows regen and unity power factor ( Advantages of both Diode Front End and Active Front End rectifiers )
• Research on automotive alternators – MOSFET-based synchronous rectifier for 12 V alternator reduces loss (A smart synchronous rectifier for 12 V automobile alternators)
• Science Advances (2024) – Superconducting diode effect demonstrated for lossless rectification at cryogenic temp (Highly Efficient Superconducting Diodes and Rectifiers for Quantum Circuitry)
• IEEE & ResearchGate – Graphene self-switching diodes for THz rectification (zero-bias, high-frequency rectifiers) (A Graphene Geometric Diode with the Highest Asymmetry Ratio and ...) ()
• TI Reference Design TIDUE54B – Totem-pole PFC in EV charger using SiC/GaN, topology and zero-crossing issue explained (98.6% Efficiency, 6.6-kW Totem-Pole PFC Ref Design for HEV/EV Onboard Charger (Rev. B)) (98.6% Efficiency, 6.6-kW Totem-Pole PFC Ref Design for HEV/EV Onboard Charger (Rev. B))
• Wikipedia/Tech notes – Definition of active rectification (using controlled switches to improve efficiency) ( Advantages of both Diode Front End and Active Front End rectifiers )
• Johansson et al., Vienna Rectifier – Three-phase active rectifier >99% efficiency in 3kW design (Design and implementation of interleaved Vienna rectifier with ...).