NXP Semiconductors BTA208-800F,127

Overview

BTA208-800F from NXP Semiconductors is a planar passivated, three-quadrant high-commutation triac in TO-220AB (SOT78) package, designed for AC power control in noisy environments. It delivers 800 V repetitive peak off-state voltage, 8 A RMS on-state current, and 65 A non-repetitive surge current, with a less-sensitive gate requiring ≤25 mA trigger current - enabling direct interfacing with microcontrollers without external amplification.

For engineers reviewing the BTA208-800F datasheet, BTA208-800F pinout, BTA208-800F application, or BTA208-800F equivalent, this device is selected for robust AC switching where dV/dt immunity, commutation reliability, and noise-resistant gate triggering are critical in thermostat and motor-control designs.

Technical Context

The BTA208-800F uses three-quadrant (3Q) triggering architecture - restricting conduction to T2+/G+, T2+/G−, and T2−/G− quadrants - which eliminates false turn-on from quadrant IV noise coupling. Its planar passivation ensures stable voltage ruggedness up to 800 V VDRM and 125 °C junction temperature operation.

It achieves high commutation capability (dIcom/dt ≥20 A/ms at 125 °C) while maintaining low gate sensitivity (IGT ≤25 mA), making it suitable for zero-crossing and phase-angle control circuits where EMI resilience and thermal stability under load surges are essential.

Key Specifications

Pinout & Package

Package: TO-220AB (SOT78), plastic single-ended package with insulated mounting base electrically connected to main terminal 2 (T2); requires mechanical mounting to heatsink for thermal management.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BTB20-800CW and MAC228A8, the BTA208-800F offers superior noise immunity and commutation performance in microcontroller-driven motor and thermostat systems - trading off 4Q flexibility and raw current rating for deterministic 3Q operation and lower gate drive burden.

Availability

BTA208-800F is available at Aetrix Electronics and suitable for electronic thermostats, general-purpose motor controls, and industrial heater controllers requiring stable component supply, long-lifecycle support, and traceable sourcing.

Supply support for BTA208-800F 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

NXP Semiconductors is a global semiconductor company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and IoT applications.

The BTA208-800F belongs to NXP's "Series F" high-commutation triac family, engineered specifically for noise-immune AC power control in microcontroller-based systems operating in electrically harsh environments.

FAQ

What is the maximum junction temperature rating for the BTA208-800F?

The BTA208-800F has a maximum junction temperature (Tj) rating of 125 °C, verified per IEC 60134 limiting values. This allows continuous operation in ambient environments up to 85 °C when mounted on a heatsink maintaining Tmb ≤102 °C, as specified in Figure 1 of the datasheet. Derating applies above that base temperature.

Does the BTA208-800F support four-quadrant triggering?

No, the BTA208-800F is a three-quadrant (3Q) triac and triggers only in quadrants I (T2+/G+), II (T2+/G−), and III (T2−/G−). Quadrant IV (T2−/G+) is intentionally disabled to improve noise immunity - a defining feature of NXP's "Series F" triacs. This behavior is confirmed in Section 1.2 and Figure 7 of the datasheet.

Can the BTA208-800F be driven directly from a 3.3 V microcontroller GPIO?

Yes - the BTA208-800F has a maximum gate trigger current (IGT) of 25 mA across all supported quadrants at 25 °C, and its gate trigger voltage (VGT) is as low as 0.7 V (typical). When paired with a series resistor (e.g., 100 Ω), a 3.3 V GPIO can deliver sufficient current to reliably trigger the BTA208-800F without external buffer circuitry.

What is the thermal resistance from junction to mounting base for the BTA208-800F?

The BTA208-800F has a thermal resistance from junction to mounting base (Rth(j-mb)) of 2 K/W for full-cycle operation, as specified in Table 5. This value assumes proper mechanical mounting with thermal interface material and enables 8 A RMS current handling with a heatsink maintained at ≤102 °C, per Figure 1.

Is the mounting base of the BTA208-800F electrically isolated?

No - the mounting base of the BTA208-800F (TO-220AB/SOT78 package) is internally connected to main terminal 2 (T2), as confirmed in Table 2 ("Pinning information") and Figure 13. Electrical isolation from chassis ground must be achieved using an insulating washer and shoulder screw, or by selecting an alternative package variant with isolated tab.