NXP Semiconductors BT1308-600D,412

Overview

BT1308-600D from NXP Semiconductors is a passivated sensitive-gate logic-level triac in SOT54 (TO-92) package, rated for 600 V repetitive peak off-state voltage (V_DRM), 0.8 A RMS on-state current (I_T(RMS)), and 7 mA maximum gate trigger current in T2−G+ quadrant. It enables direct interfacing with low-power logic ICs and is used in low-power AC fan speed control and general-purpose phase-control circuits.

For engineers reviewing the BT1308-600D datasheet, BT1308-600D pinout, BT1308-600D application, or BT1308-600D equivalent, key selection factors include its 600 V blocking capability, 7 mA T2−G+ gate sensitivity, 9 A non-repetitive surge rating (t = 20 ms), TO-92 thermal resistance (R_th(j-lead) ≤ 60 K/W), and four-quadrant triggering compatibility with microcontroller GPIOs.

Technical Context

The BT1308-600D operates as a bidirectional thyristor switch with sensitive gate triggering across all four quadrants (T2+/G+, T2+/G−, T2−/G−, T2−/G+), enabling flexible control from digital logic without external amplification. Its gate trigger voltage remains below 2 V at 25 °C and stays within 0.7 V at 110 °C, supporting stable turn-on over temperature.

It features a dV/dt immunity of ≥45 V/µs (off-state) and ≥5 V/µs (commutating), with turn-on time under 2 µs when driven by 25 mA gate pulses. The device sustains 125 °C junction temperature and requires lead temperature ≤55 °C to maintain full 0.8 A RMS current rating.

Key Specifications

Pinout & Package

SOT54 (TO-92) plastic single-ended leaded through-hole package with 3 leads; compact footprint (5.2 × 4.2 mm body, 14.5 mm lead length) optimized for manual assembly and low-cost PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BT134-600D and MAC97A6, the BT1308-600D offers superior gate sensitivity and broader triggering quadrant support, making it optimal for low-power microcontroller-driven phase control where layout simplicity and thermal efficiency are prioritized over legacy compatibility.

Availability

BT1308-600D is available at Aetrix Electronics and suitable for AC fan speed control, smart plug load switching, and small appliance heater control requiring stable component supply and long-lifecycle availability.

Supply support for BT1308-600D 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 high-performance mixed-signal and RF solutions for automotive, industrial, and consumer markets.

The BT1308 series belongs to NXP's logic-level triac product line, designed specifically for cost-sensitive, low-power AC control applications where direct microcontroller interfacing and robust thermal performance in TO-92 packages are essential.

FAQ

What is the maximum gate trigger current specification for BT1308-600D in the T2−G+ quadrant?

The BT1308-600D has a maximum gate trigger current (I_GT) of 7 mA in the T2−G+ quadrant at 25 °C, per Table 5 of the official NXP datasheet. This value increases slightly with junction temperature but remains within 10 mA up to 110 °C. This low threshold enables reliable triggering directly from 3.3 V or 5 V microcontroller GPIO pins without external amplification, a key design advantage of the BT1308-600D.

Can BT1308-600D be used in 230 V AC mains applications?

Yes, the BT1308-600D is rated for 600 V repetitive peak off-state voltage (V_DRM), providing sufficient margin for 230 V RMS AC mains (peak ≈ 325 V) including transient surges. Its 9 A non-repetitive surge rating (t = 20 ms) further supports safe operation during inrush events. Designers must ensure proper snubbing, heat sinking, and gate drive isolation per IEC 61000-4-5 requirements when deploying BT1308-600D in 230 V systems.

What is the thermal resistance from junction to lead (R_th(j-lead)) for BT1308-600D?

The BT1308-600D has a maximum thermal resistance from junction to lead (R_th(j-lead)) of 60 K/W, as specified in Table 4 of the NXP datasheet. This value applies under full-cycle conduction conditions and enables the device to dissipate up to ~1.36 W (at 0.8 A and 1.7 V drop) while maintaining junction temperature ≤125 °C when lead temperature is held at ≤55 °C-critical for compact, unventilated designs using the BT1308-600D.

Does BT1308-600D support four-quadrant triggering?

Yes, the BT1308-600D supports full four-quadrant triggering (T2+/G+, T2+/G−, T2−/G−, T2−/G+) as confirmed in Section 1.2 "Features" and Table 5 of the NXP datasheet. This allows gate control signals of either polarity relative to T1 and T2, enabling compatibility with AC-coupled drivers, optocouplers with bipolar output, and microcontrollers using software-configurable GPIO polarity-all without external level-shifting circuitry in the BT1308-600D implementation.

What is the RMS on-state current rating for BT1308-600D and under what conditions?

The BT1308-600D has an RMS on-state current (I_T(RMS)) rating of 0.8 A, valid for full sine-wave conduction with lead temperature (T_lead) maintained at ≤55 °C, as defined in Table 3 and Figure 4 of the NXP datasheet. Exceeding this lead temperature reduces allowable current linearly; at 75 °C lead temperature, the rating drops to approximately 0.6 A. This derating behavior must be accounted for in thermal design when using BT1308-600D in enclosed or high-ambient environments.