SanRex PK55FG160 1600V 55A Dual Thyristor Module: Features, Specifications, and Applications

SanRex PK55FG160 1600V 55A Dual Thyristor Module

The SanRex PK55FG160 is an isolated dual thyristor module developed for low-frequency power rectification and AC phase control. Integrating two high-voltage thyristor chips in a series-connected topology, it provides reliable switching performance under demanding thermal cycles. This module serves as a critical component in control systems where galvanic isolation and high voltage safety margins are required.

Core Specifications: 1600V Repetitive Peak Voltage | 55A Average On-State Current | 2500V AC Isolation Voltage

• Key Benefit: Excellent thermal cycling capability via isolated copper baseplate construction.
• Design Advantage: Simplified mounting layout with standard screw terminals for reliable mechanical contact.

Download Official Datasheet (PDF)

Isolated Package Design and Electrical Performance

The technical foundation of the PK55FG160 centers on its high blocking voltage capability and robust thermal isolation. Operating at up to 1600V, the thyristors safely withstand transient voltage spikes commonly found on raw industrial main supplies. This high voltage headroom is essential for system longevity in noisy electrical environments.

The internal semiconductor chips are electrically isolated from the metallic baseplate. This layout is built on isolated baseplates that provide a dielectric isolation barrier rated up to 2500V AC. This structural isolation allows engineers to mount multiple modules on a single shared heatsink without risking short circuits between phases.

To manage the thermal energy generated during continuous on-state conduction, the module features a low junction-to-case thermal resistance ($R_{th(j-c)}$) of 0.45 °C/W per thyristor. You can visualize thermal resistance as the physical restriction of a fluid pipe; a lower value acts like a wider pipe, allowing heat to flow rapidly from the silicon junction to the heatsink. This efficient heat path prevents localized thermal runaway.

Target Applications and Integration Advantages

This dual thyristor configuration is well-suited for several power electronics designs within the power semiconductors category:

• AC Motor Control: Provides stable phase control for soft-start applications, handling high inrush currents without degradation.
• Temperature Controllers: Operates efficiently in phase-angle controllers for industrial heating systems.
• Power Supplies: Rectifies AC input stages in heavy-duty battery chargers and DC power distribution panels.

The PK55FG160 is best matched for phase-controlled rectification and AC switching applications in environments requiring strict galvanic isolation and compact footprints.

Key Specifications

Parameter	Symbol	Value / Rating	Conditions
Repetitive Peak Off-State Voltage	VDRM / VRRM	1600 V	Tj = -40 to 125 °C
Average On-State Current	IT(AV)	55 A	Single phase, half wave, Tc = 80 °C
Surge On-State Current	ITSM	1100 A	50 Hz, 1 cycle, peak, non-repetitive
I2t Value for Fusing	I2t	6000 A2s	t = 10 ms (50 Hz half cycle)
Gate Trigger Current (Max)	IGT	150 mA	Tj = 25 °C, VD = 6V
Isolation Breakdown Voltage	VISO	2500 V AC	1 minute, terminals to base
Thermal Resistance (Junction to Case)	Rth(j-c)	0.45 °C/W	Per single thyristor arm

Engineer FAQ

How do you determine the required thermal resistance of the heatsink for the PK55FG160?

To prevent the junction temperature from exceeding 125 °C, calculate the total power dissipation using the on-state voltage drop and current. Then, use the formula $R_{th(c-f)} + R_{th(f-a)} le (T_{j(max)} – T_a) / P_{tot} – R_{th(j-c)}$ to select a heatsink that meets the necessary dissipation efficiency.

What is the recommended mounting torque for case and terminal installation?

For secure mechanical and thermal performance, mounting to the heatsink should use a torque of 4.0 to 4.5 N·m. The electrical terminals require a torque of 2.5 to 3.5 N·m using standard M5 screws. Tightening outside these limits can damage the internal structure or increase contact resistance.

When should I transition from the PK55FG160 to a higher capacity module like the PK110FG160?

A transition to the PK110FG160 is recommended when the continuous current requirements of your application exceed 55A average, or if the expected transient surge currents exceed the 1100A peak rating of the 55A device.

Summary

The PK55FG160 dual thyristor module provides electrical isolation and high thermal conductivity. It is designed to handle continuous load currents up to 55A at line voltages up to 1600V. This balanced specification helps engineers maintain high safety margins in compact industrial AC and DC power distribution configurations.