Content last revised on February 2, 2026
VHF28-12io5 IXYS High-Efficiency Single Phase Half-Controlled Rectifier Bridge
The VHF28-12io5, a specialized component within the IXYS Thyristor/Diode Module family, is a 1200V, 28A single-phase rectifier bridge designed for robust power management in industrial environments. By integrating thyristor-diode rectification with a dedicated fast-recovery freewheeling diode, it eliminates the need for external discrete components in DC link applications. For industrial power supplies prioritizing footprint reduction and reliability under inductive loads, this 1200V module is the optimal choice.
Application Scenarios & Value
Achieving System-Level Benefits through Integrated Topology
Engineers often face the challenge of managing back-EMF and inductive energy spikes while attempting to minimize PCB real estate in motor control and charging circuits. The VHF28-12io5 addresses this by incorporating a plane-passivated bridge with a 1200V blocking capacity. This integration is particularly valuable in Battery Charging units and UPS systems where seamless energy commutation is required.
In DC Motor Drives, the internal freewheeling diode acts as a critical safety path for reactive power, preventing voltage overshoot that could otherwise damage sensitive IGBT gate drivers. When compared to systems using discrete components, this module offers a significant reduction in parasitic inductance. For designers requiring three-phase rectification for higher power tiers, the VUB72-16NO1 provides a logical progression in the same ECO-PAC1 footprint. Integrating this module into a Soft Start circuit ensures a controlled power-up sequence, reducing mechanical stress on connected machinery.
Technical Deep Dive
Engineered for Thermal Resilience and Design Simplification
The structural integrity of the VHF28-12io5 is centered around its isolated DCB (Direct Copper Bonded) ceramic base. Think of this DCB substrate as a thermal "superhighway"; it transports heat away from the silicon junctions with the same efficiency that a high-performance heat sink protects a computer processor, ensuring the 28A current rating is maintained even at 85°C case temperatures. This high 3000V~ isolation voltage allows multiple modules to be mounted on a single grounded heat sink without risk of electrical breakdown.
Furthermore, the chips utilize plane passivation technology. This process can be compared to an invisible glass shield protecting a delicate painting; it seals the semiconductor junction against moisture and ionic impurities, significantly enhancing the module's long-term blocking stability. This robustness is essential in applications following IEC 61800-3 standards for industrial drives, where voltage transients are frequent. Understanding these characteristics is vital for modern power electronics where reliability defines the total cost of ownership.
Key Parameter Overview
Functional Specification Grouping for Engineering Assessment
| Parameter Category | Technical Specification | Value / Rating |
|---|---|---|
| Voltage Ratings | Max. Non-Repetitive Reverse Voltage (V_RSM) | 1300V |
| Voltage Ratings | Max. Repetitive Reverse Voltage (V_RRM) | 1200V |
| Current Output | Average Forward Current (I_dAV) @ Tc=85°C | 28A |
| Thermal Dynamics | Thermal Resistance Junction to Case (RthJC) | 1.1 K/W (Thyristor) |
| Isolation | Isolation Voltage (V_ISOL) 50/60 Hz, RMS | 3000V~ |
| Mechanical | Package Type / Mounting | ECO-PAC1 / Solderable Pins |
Download the VHF28-12io5 datasheet for detailed specifications and performance curves.
FAQ
How does the integrated freewheeling diode benefit inductive load switching?
The internal diode provides a low-impedance path for current when the thyristors are turned off, preventing inductive "kickback" from generating high-voltage spikes that could lead to catastrophic failure.
What is the primary benefit of the ECO-PAC1 package in this module?
It offers a compact, low-profile design with solderable pins, which simplifies automated PCB assembly and provides a high power-to-weight ratio for space-constrained industrial enclosures.
Why is the 3000V isolation rating significant for system safety?
This high dielectric strength ensures that the high-voltage power stage is safely isolated from the chassis and control circuitry, meeting stringent international safety standards for industrial equipment.
Does the plane passivation technology affect the reliability of the thyristors?
Yes, it creates a stable surface for the silicon junction, which reduces leakage currents and enhances the module's ability to withstand high temperatures and voltage stress over time.
Can the VHF28-12io5 be used in single-phase motor speed control?
Absolutely. Its half-controlled bridge topology allows for phase-angle control of the output voltage, making it a standard choice for basic DC motor speed regulation.
For technical procurement and engineering support regarding the IXYS VHF28-12io5, please contact our technical sales team to verify current specifications for your specific application requirements.
