ZDT6705TA

Overview

The ZDT6705TA is a complementary medium power Darlington transistor pair from Diodes Incorporated, housed in an SM-8 (SOT-223) package. It integrates one NPN and one PNP die within a single component. The NPN section supports a collector-emitter voltage of 120V and continuous current up to 1A, while the PNP section provides -120V and -1A respectively. Both transistors feature high static forward current transfer ratios ranging from 2K to 100K depending on load conditions. The device operates across a temperature range of -55°C to +150°C with total power dissipation capabilities up to 2.75W.

Feature Summary

• Complementary NPN/PNP configuration in a single compact surface-mount package
• High gain characteristics suitable for direct drive applications
• Robust thermal performance with junction-to-ambient resistance as low as 45.5°C/W

Applications

• Motor control circuits requiring complementary switching
• Power amplifier stages utilizing push-pull configurations
• Relay driver interfaces needing high input impedance

Procurement Notes

Verify the specific ordering suffix against manufacturer documentation to confirm tape and reel specifications or marking details. Ensure the procurement channel sources genuine components matching the SM-8 package outline. Cross-reference the part number with official Diodes Incorporated catalogs to validate availability and revision status before finalizing supply chain agreements.

Selection Notes

Select this component when a matched complementary pair is required for medium-power switching tasks. The high hFE values reduce base drive requirements compared to standard bipolar transistors. Consider the thermal resistance limits and ensure adequate PCB copper area for heat dissipation during continuous operation at maximum ratings.

Part Context

This device belongs to the ZDT series of complementary Darlington transistors designed for integrated power switching solutions. The SM-8 package allows for space-efficient board layouts while maintaining electrical isolation between the two dies. It serves as a monolithic alternative to discrete complementary transistor pairs, simplifying assembly and improving matching characteristics.

Replacement Considerations

Direct replacements include other complementary Darlington pairs in SOT-223 packages such as the BD679 or similar high-voltage variants. Verify pinout compatibility and thermal derating curves when substituting. Ensure the replacement maintains the required breakdown voltages and saturation characteristics for the specific circuit application.