QK008VH4TP

Triacs Overview

The Littelfuse QK008VH4TP is a bidirectional triac from the Qxx08xHx series, designed for AC switching and phase control applications. It features an 8 A RMS on-state current and supports rated repetitive off-state voltages of 400 V, 600 V, 800 V, or 1000 V. The device utilizes Alternistor technology, enabling operation in quadrants I, II, and III without requiring a snubber network. Key electrical parameters include a maximum holding current of 35 mA, a gate trigger voltage of 1.3 V, and a gate trigger current of 35 mA. It operates within a temperature range of -40°C to +125°C and is housed in a TO-251-3 (DPAK) through-hole package.

Triacs Feature Summary

• Alternistor construction eliminates the need for external snubber networks in high dv/dt circuits
• Sensitive gate type ensures reliable triggering in quadrants I and IV for digital control compatibility
• Glass-passivated junctions provide long-term parameter stability and device reliability

Triacs Applications

• AC solid-state switches and static switching relays
• Motor speed controls and temperature modulation systems
• Lighting controls and light dimmers

Triacs Procurement Notes

Verify the specific voltage rating suffix in the part number against the design requirements, as the series covers multiple voltage classes. Confirm the package type matches the PCB layout constraints. Ensure the gate sensitivity aligns with the driving circuit capabilities. Check RoHS compliance status if required by the manufacturing process. Validate thermal management strategies for the TO-251-3 package under peak load conditions.

Triacs Selection Notes

Select this component for applications requiring high commutation performance with inductive loads. The Alternistor feature simplifies circuit design by removing snubber components. Ensure the gate drive circuit can supply at least 35 mA to guarantee reliable turn-on. Consider the 8 A current rating relative to the expected load and ambient temperature derating curves. Verify that the chosen voltage rating exceeds the peak line voltage plus transient spikes.

Triacs Part Context

This part belongs to the Lxx08xx, Qxx08xx, and Qxx08xHx series of 8 Amp bidirectional triacs. These devices are engineered for robust AC power control. The Qxx08xHx designation specifically denotes the Alternistor variant optimized for high dv/dt immunity. The series is recognized to UL 1557 standards for electrically isolated semiconductor devices.

Triacs Replacement Considerations

Compatible substitutes include other 8 A Alternistor triacs in TO-251-3 packages from manufacturers such as STMicroelectronics or ON Semiconductor. Ensure the replacement maintains the same voltage rating, gate trigger characteristics, and thermal resistance values. Verify pinout compatibility to avoid PCB redesign.