Content last revised on September 10, 2026
SanRex PK55GB80 Dual Thyristor Module: 800V 55A Solid-State Power Control
The SanRex PK55GB80 is an industrial-grade dual thyristor module engineered to deliver robust phase control, line rectification, and high-surge endurance in compact power electronic assemblies. With an operating rating of 800V repetitive peak off-state voltage (VDRM / VRRM) and 55A average on-state current (IT(AV) at Tc = 89°C), this module provides a dependable switching platform for line voltages up to 240V/480V AC.
Engineers integrating solid-state switching often struggle with transient overvoltages and steep line disturbances. The PK55GB80 resolves this by combining a critical rate of off-state voltage rise (dv/dt) of 500 V/µs with a high non-repetitive surge current rating (ITSM) of 1100A (60Hz), preventing premature misfiring and catastrophic junction punch-through during line spikes.
What is the primary operational advantage of the PK55GB80? It delivers high-surge transient suppression and electrically isolated mounting in a single rugged housing. How does isolated packaging simplify assembly? The 2500V AC isolation baseplate eliminates external insulating mica sheets on shared heatsinks. For 240V/480V industrial line controls requiring high surge ruggedness and compact footprints, the SanRex PK55GB80 is the optimal choice.
Key Parameter Overview
Decoding the Electrical and Thermal Specifications for Power Stage Design
The following technical parameters outline the absolute ratings and electrical characteristics of the SanRex PK55GB80 module, referenced under standard testing conditions:
| Parameter Category | Technical Parameter | Symbol | Rating / Value | Test Conditions |
|---|---|---|---|---|
| Voltage Ratings | Repetitive Peak Reverse Voltage | VRRM | 800V | Tj = -40°C to +125°C |
| Repetitive Peak Off-State Voltage | VDRM | 800V | Gate open circuit | |
| Non-Repetitive Peak Reverse Voltage | VRSM | 960V | Transient surge condition | |
| Current Capabilities | Average On-State Current | IT(AV) | 55A | Single phase, half wave 180°, Tc = 89°C |
| R.M.S. On-State Current | IT(RMS) | 86A | Continuous sinusoidal | |
| Surge On-State Current | ITSM | 1000A / 1100A | Half-cycle, 50Hz / 60Hz, non-repetitive | |
| I2t Value for Fusing | I2t | 5000 A2s | t = 10 ms (50Hz) | |
| Dynamic Characteristics | Critical Rate of Rise of On-State Current | di/dt | 150 A/µs | Gate drive IG = 100mA, di/dt = 1 A/µs |
| Critical Rate of Rise of Off-State Voltage | dv/dt | 500 V/µs | Tj = 125°C, linear to 67% VDRM | |
| Gate & Thermal Limits | Gate Trigger Current / Voltage | IGT / VGT | 100 mA / 3.0 V | VD = 6V, IT = 1A |
| Thermal Resistance (Junction to Case) | Rth(j-c) | 0.53 °C/W | Per module (both junctions active) | |
| Dielectric Isolation Breakdown | VISO | 2500V AC | 1 minute, terminals to mounting base |
Download the PK55GB80 datasheet for detailed specifications and performance curves.
Application Scenarios & Value
Robust Solid-State Control Across Industrial Systems
Engineers designing high-power heating elements or soft starters encounter significant current surges during system startup. In an industrial annealing furnace, resistive elements draw heavy inrush currents when cold. The PK55GB80 absorbs these events through its 1100A surge rating and robust 5000 A2s fuse-matching budget, preventing silicon degradation during repeated thermal cycles.
The module serves as a workhorse in diverse line-frequency applications:
- Industrial Heater Controls & Ovens: Precise phase-angle or burst-firing AC power regulation.
- AC/DC Motor Drives & Soft Starters: Controlled line rectifiers for smooth motor acceleration in Variable Frequency Drive (VFD) front-ends.
- Static Transfer Switches & Bypass Units: Arc-free, instant phase selection in UPS (Uninterruptible Power Supply) networks.
- Battery Charging & DC Power Supplies: Reliable controlled rectification in battery backup plants.
For systems handling moderate loads, this 55A module provides balanced efficiency. When expanding to higher voltage or current applications, related modules such as the SKKT57B12E provide a 1200V blocking rating, while the SKKT106/12E offers higher current carrying capability for heavy-duty industrial platforms.
Technical & Design Deep Dive
Thermal Optimization, dv/dt Immunity, and Structural Ruggedness
The PK55GB80 integrates two series-connected Silicon Controlled Rectifiers (SCRs) on an electrically isolated copper baseplate. Think of the 2500V AC isolation barrier as a built-in electrical bulkhead: it prevents voltage bleed-through into the heatsink chassis without needing external ceramic pads, simplifying the thermal management stackup.
Operating in harsh electromagnetic environments creates steep line noise. A high dv/dt of 500 V/µs acts like a high-tension shock absorber, preventing parasitic displacement currents through junction capacitances from falsely triggering the SCR gate. Designers can consult our power semiconductor selection guide to align gate-firing pulses and RC snubber dimensions with inductive load parameters.
Frequently Asked Questions
Engineering Inquiries and Operational Best Practices
How does the 5000 A2s rating of the PK55GB80 influence semiconductor fuse selection?
The module's I2t rating defines its total thermal energy absorption limit before die destruction. Engineers must select an ultra-fast semiconductor fuse with a total clearing I2t lower than 5000 A2s (at 10 ms) to guarantee circuit isolation during short circuits.
Why is the 2500V AC isolated baseplate significant for multi-module rectifier bridges?
Because the internal active junctions are electrically insulated from the mounting base, multiple PK55GB80 units can be mounted directly onto a common aluminum heatsink without separate insulation sheets, lowering thermal resistance and assembly complexity.
Procurement and Technical Verification
Our sales and technical support teams provide comprehensive verification for SanRex PK55GB80 dual thyristor modules. Submit your bill of materials (BOM) or RFQ today to obtain component datasheets, verify batch traceability, and receive competitive volume pricing for your production schedules.
