What is a Trans-Inductance Voltage Regulator (TLVR)?

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Editorial Team - everything PE

Apr 26, 2024

A trans-inductor voltage regulator (TLVR) is a multi-phase voltage regulator that powers low-voltage, high-current, multi-phase applications such as data centers, storage systems, graphics cards, and personal computing. This voltage regulator utilizes a trans-inductor to regulate voltage. A trans-inductor, also known as a transformer-inductor, is a component that combines the functions of both an inductor and a transformer. These regulators are designed to achieve swift dynamic response, making them ideal for applications requiring rapid adjustments in large current supply.

Conventional voltage regulators use inductors to stabilize voltage fluctuations by storing and releasing energy. A transformer, on the other hand, is commonly used to step up or step down voltage levels in electrical systems. In a TLVR, the trans-inductor is designed to perform both tasks simultaneously. This allows efficient voltage regulation and reduces the size and complexity of the overall circuit compared to using separate inductors and transformers.

TLVR Architecture

Voltage regulators (VRs) must exhibit quicker dynamic responses during load transients to meet the output voltage ripple requirements. A TLVR structure facilitates extremely fast load transient response and substantially shrinks the size and cost of output capacitors. The structure uses TLVR inductors that replace the output inductors in traditional multiphase VRs. A TLVR inductor is a 1:1 transformer with a primary winding and a secondary winding. All the TLVR inductors are coupled through their secondary windings. The current in the secondary side of the TLVR inductor is attributed to the control signals of all different phases. Due to the coupling effect, when the duty cycle of one phase of the VR changes in response to a load transient, the output current of all phases can simultaneously increase or decrease. This feature contributes to the exceptional load transient performance achievable with the TLVR structure.

A transformer-based VR comprises of a step-down transformer with a high and flexible step-down ratio, a simple and compact structure, and high efficiency. In contrast to transformerless multiphase voltage regulators, transformer-based models accommodate significantly higher input voltages, thereby revolutionizing VR design and enhancing overall efficiency. The TLVR circuit replaces the phase inductors present in multiphase VRs with transformers and connects their respective secondary windings in series with an additional inductor. The phases are driven by interleaved pulse-width modulated (PWM) waveforms.  In the event of a transient in the load, the duty cycle of the PWM waveform of a phase is adjusted such that all phases respond with a changed current. This design results in an extremely fast transient response that matches the demands of the load in amperage and bandwidth. 

The TLVR architecture allows for swift and efficient response to changes in power demand with current requirements greater than 1000A, making it particularly well-suited for applications where rapid adjustments in large current supply are essential. 

Advantages of TLVR

  • Fast transient response: The TLVR architecture enables extremely fast transient response on multiphase voltage regulators, which is particularly beneficial for applications where rapid adjustments in large current supply are essential.
  • Improved transient performance: The TLVR provides outstanding transient performance, making it particularly well-suited for applications such as CPUs, GPUs, and ASICs that have very aggressive transient specifications.
  • Design and layout flexibility: The TLVR allows for design and layout flexibility, which can be advantageous for various high-current applications.
  • Reduced output capacitance: The TLVR provides reduced output capacitance, which can be beneficial for reducing the overall solution size and improving the system's performance.
  • Lower electromagnetic interference (EMI): The TLVR architecture provides lower EMI, which can be advantageous for various applications where electromagnetic compatibility is a concern.
  • Few manufacturability, layout, and stock-keeping unit constraints: The TLVR is extensible to any number of phases, and even at high phase counts, it has few manufacturability, layout, and stock-keeping unit constraints.
  • Independently adjustable compensation inductor: The compensation inductor is independently adjustable, which enables optimal trade-off between transient performance and loop stability.

Applications of TLVR

  • Power Supplies: TLVRs are widely used in power supply units for electronic devices, such as computers, televisions, and mobile phones. They help stabilize the voltage output, ensuring consistent and reliable power delivery to the connected devices.
  • Renewable Energy Systems: TLVRs play a crucial role in renewable energy systems, such as solar and wind power plants. They help manage voltage fluctuations in the generated power, ensuring compatibility with the grid or storage systems.
  • Electric Vehicles (EVs): TLVRs are employed in EV charging systems and battery management systems to regulate the voltage during charging and discharging processes. This ensures the safe and efficient operation of the vehicle's electrical components.
  • Industrial Automation: TLVRs are used in industrial automation systems to regulate voltage levels for various machinery and equipment. They help maintain a stable power supply, which is critical for the reliable operation of industrial processes.
  • Telecommunications: TLVRs are utilized in telecommunications infrastructure, including base stations and networking equipment, to ensure stable voltage supply for optimal performance and reliability of communication systems.
  • Medical Devices: TLVRs are integrated into medical devices, such as MRI machines, CT scanners, and patient monitors, to provide precise and stable voltage supply, ensuring the accuracy and safety of medical procedures.
  • Aerospace and Defense: TLVRs are deployed in aerospace and defense applications, including aircraft, satellites, and military vehicles, to regulate voltage for onboard electronics and communication systems, ensuring mission-critical functionality.
  • Consumer Electronics: TLVRs are used in various consumer electronic devices, such as laptops, smartphones, and gaming consoles, to maintain stable voltage levels for efficient operation and protection of sensitive components.