SRUK208RTP

Overview

The Littelfuse SRUK208RTP is an 8 Amp standard Silicon Controlled Rectifier (SCR) from the TECCOR brand, housed in a TO-220AB non-isolated mounting tab package. It features a high forward blocking voltage of 1200V and supports a critical rate-of-rise of on-state current (di/dt) of 350 A/μs. The device has an RMS on-state current rating of 8A at a case temperature of 105°C and an average on-state current of 5.1A. Key electrical characteristics include a maximum gate trigger current of 15 mA, a peak non-repetitive surge current of 83A at 50Hz, and a junction-to-case thermal resistance of 1.8 °C/W.

Feature Summary

• Engineered for high-voltage capacitor discharge applications with robust pulse current handling capabilities.
• Features a high forward blocking voltage of 1200V suitable for demanding power switching environments.
• Designed with a high di/dt capability to manage rapid current transitions during turn-on events.

Applications

• High voltage pulse generation via capacitor discharge circuits
• Electric fence energizers
• Contact electric weapons (CEWs)
• High-power strobe light ignition systems

Procurement Notes

Verify the specific ordering suffix 'T' corresponds to the tube packing mode containing 500 units per base quantity as documented in the official datasheet. Confirm that the component meets RoHS compliance standards required for your assembly process. Ensure the TO-220AB package dimensions align with your PCB footprint and thermal management design constraints before finalizing procurement orders.

Selection Notes

Select this component when designing circuits requiring high voltage blocking capabilities up to 1200V combined with significant pulse current handling. The 350 A/μs di/dt rating makes it suitable for fast-switching capacitor discharge loads. Consider the 1.8 °C/W junction-to-case thermal resistance for heat sink sizing calculations to maintain junction temperatures within the specified -40 to 125°C operating range under continuous or repetitive load conditions.

Part Context

This part belongs to the SRUK208x series of TECCOR brand thyristors, which are specifically optimized for high-voltage capacitor discharge applications. The series includes variants such as the SRUK208D for surface mount packaging. The SRUK208RTP designation indicates the through-hole TO-220R package variant supplied in tube format, distinguishing it from other package types within the same electrical family.

Replacement Considerations

The SRUK208DRP serves as a functional equivalent within the same series but utilizes a TO-252AA surface mount package. Substitution requires verifying compatibility with the existing PCB footprint and thermal interface design, as the physical mounting and lead configuration differ significantly between the TO-220 and TO-252 packages.

FAQ

Is the SRUK208RTP designed to conduct current in the reverse direction?

No, the datasheet explicitly states that the reverse direction is not designed to function. It operates as a standard SCR with unidirectional current flow capability.

What is the maximum non-repetitive peak off-state voltage for this device?

The VDSM parameter specifies a non-repetitive peak off-state voltage of 1400V at a junction temperature of 25°C.

How does the junction temperature affect the gate trigger current?

According to Figure 1 in the datasheet, the normalized DC gate trigger current increases as the junction temperature decreases. The ratio of IGT at lower temperatures relative to 25°C rises, indicating higher gate sensitivity at colder operating conditions.