STMicroelectronics T405-800H

Overview

T405-800H from STMicroelectronics is a 4 A, 800 V three-quadrant logic-level triac in IPAK package, designed for AC phase-control switching of inductive loads with low gate trigger current (5 mA max), high commutation robustness, and snubberless operation. It enables compact motor control in power tools and kitchen appliances.

For engineers reviewing the T405-800H datasheet, T405-800H pinout, T405-800H application, or T405-800H equivalent, key selection criteria include VDRM/VRRM rating, IGT sensitivity, dV/dt immunity, thermal resistance (Rth(j-c) = 2.6 °C/W), and IPAK mounting compatibility for high-reliability AC load switching.

Technical Context

The T405-800H uses ST's Snubberless logic-level technology to achieve 20 V/µs minimum dV/dt at 125 °C without external snubbers, supporting direct microcontroller gate drive. Its three-quadrant operation excludes quadrant IV, reducing false triggering in noisy AC environments.

It delivers 4 A RMS on-state current at Tc = 110 °C with 1.56 V max VTM and 120 mΩ dynamic resistance, enabling efficient conduction in universal motor and solenoid driver circuits where thermal management and gate drive simplicity are critical.

Key Specifications

Pinout & Package

IPAK package: Insulated plastic package with integrated heatsink tab, lead-free, UL94 V0 compliant, recommended torque 0.4–0.6 N·m. Dimensions per Table 8 (A = 2.20–2.40 mm, D = 6.0–6.20 mm, E = 6.40–6.65 mm, H = 16.10 mm).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar triac-based AC switching applications.

Compared with T405-800B and T410-800H, the T405-800H uniquely balances ultra-low gate drive (5 mA), superior thermal performance (2.6 °C/W), and IPAK mountability-making it optimal for space-constrained, thermally demanding, logic-driven AC motor controls.

Availability

T405-800H is available at Aetrix Electronics and suitable for power tools, kitchen appliances, and electrovalve control requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for T405-800H includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, specializing in power discrete devices, analog ICs, and microcontrollers for industrial, automotive, and consumer markets.

The T4 series triacs were developed specifically for snubberless, logic-level AC switching in cost-sensitive, high-volume home appliance and power tool applications-emphasizing reliability, ease of drive, and thermal efficiency.

FAQ

Is the T405-800H compatible with 3.3 V microcontroller GPIOs?

Yes. With a maximum gate trigger current of 5 mA and typical VGT of 1.3 V, the T405-800H can be directly driven by 3.3 V or 5 V MCUs using a series resistor (e.g., 470 Ω for ~5 mA at 3.3 V). Gate drive must respect polarity relative to A1 and avoid exceeding 4 A peak IGM.

Does the T405-800H require a heatsink in 4 A continuous operation?

Yes. At 4 A RMS and Tc = 110 °C, junction temperature reaches ~125 °C with Rth(j-c) = 2.6 °C/W. A heatsink maintaining Tc ≤ 110 °C is mandatory; ambient-only operation exceeds safe limits even with generous copper pour.

What is the difference between T405-800H and T405-800T?

T405-800H uses the IPAK package (0.4 g, 16.1 mm height), optimized for surface-mount thermal performance (Rth(j-c) = 2.6 °C/W). T405-800T uses TO-220AB (2.3 g, insulated/non-insulated variants), offering higher creepage/clearance but lower thermal efficiency (Rth(j-c) = 2.6 °C/W only for non-insulated version; insulated is ~3.5 °C/W).

Can the T405-800H replace a BT136 or BTA06 in existing designs?

No direct replacement. The T405-800H has lower IGT (5 mA vs. 15–50 mA) and higher dV/dt immunity (20 V/µs vs. 10–15 V/µs), but differs in package (IPAK vs. TO-220/TO-92) and pinout. Mechanical and thermal redesign is required; electrical validation must confirm commutation behavior under actual load conditions.