NXP Semiconductors BT131-800D,112

Overview

BT131-800D from NXP Semiconductors is a passivated, sensitive-gate logic-level triac in SOT54 (TO-92) package, rated for 800 V repetitive peak off-state voltage (V_DRM) and 1 A RMS on-state current (I_T(RMS)), with gate trigger current as low as 5 mA in three quadrants-designed for direct interfacing with microcontrollers and low-power logic circuits in AC phase-control applications such as dimmers and motor speed controllers.

For engineers reviewing the BT131-800D datasheet, BT131-800D pinout, BT131-800D application, or BT131-800D equivalent, this page delivers verified triac specifications including V_DRM, I_T(RMS), I_GT, V_GT, and thermal resistance-critical for snubberless design, zero-crossing compatibility, and PCB layout validation in 50/60 Hz AC control systems.

Technical Context

The BT131-800D operates as a bidirectional thyristor with four-quadrant triggering capability, where T2+G+, T2+G−, and T2−G− quadrants support ≤5 mA gate trigger current at 25 °C, enabling reliable turn-on from CMOS/TTL outputs without external amplification. Its dV/dt immunity of 20–50 V/μs (at 125 °C) and commutating dV_com/dt rating of 3–5 V/μs ensure stable operation under noisy line conditions.

Thermal performance is defined by junction-to-lead resistance up to 80 K/W (half-cycle) and junction-to-ambient resistance up to 150 K/W when mounted on PCB with 4 mm lead length-making heatsinking optional for ≤1 A continuous conduction at T_lead ≤51.2 °C per Figure 5.

Key Specifications

Pinout & Package

SOT54 (TO-92) plastic single-ended leaded through-hole package with 3 leads, epoxy meeting UL94 V-0 at 1/8 inch thickness; body dimensions: 5.2 × 4.8 × 14.5 mm (L×D×L).

Key Features

Applications

Equivalent & Alternatives

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

Compared with BT131-800D, BT131-800E offers identical electrical and thermal behavior with minor packaging revision, while MAC97A6 trades voltage headroom and gate sensitivity for lower cost-making BT131-800D the optimal choice for robust, snubberless 230 VAC phase control with direct MCU integration.

Availability

BT131-800D is available at Aetrix Electronics and suitable for AC dimming, small-appliance motor control, and smart plug power switching requiring stable component supply, long-term lifecycle support, and traceable sourcing for production volumes.

Supply support for BT131-800D 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 BT131 series belongs to NXP's logic-level triac product line, engineered specifically for direct microcontroller interfacing in cost-sensitive, space-constrained AC control systems-emphasizing low gate drive power, high dV/dt immunity, and TO-92 manufacturability.

FAQ

What is the maximum repetitive peak off-state voltage (V_DRM) for BT131-800D?

The BT131-800D has a guaranteed V_DRM of 800 V, meaning it can block up to 800 V of repetitive AC voltage in the off-state without turning on-providing sufficient margin for 230 VAC mains (peak ≈325 V) and common line transients. This rating is confirmed in Table 3 of the NXP datasheet Rev. 3 (2011) and applies specifically to the BT131-800D and BT131-800E variants.

Can BT131-800D be driven directly by a 3.3 V microcontroller GPIO?

Yes, BT131-800D can be driven directly by a 3.3 V microcontroller GPIO because its gate trigger current (I_GT) is ≤5 mA in T2+G+, T2+G−, and T2−G− quadrants at 25 °C, and its gate trigger voltage (V_GT) is ≤1.5 V. This ensures reliable turn-on even with typical MCU output impedance and voltage drop under load-no external transistor or level shifter is needed for basic phase-control operation.

What is the thermal resistance from junction to ambient (R_th(j-a)) for BT131-800D?

The BT131-800D has a maximum R_th(j-a) of 150 K/W when mounted on a printed-circuit board with 4 mm lead length (Table 4). This value assumes natural convection and no heatsink; actual thermal performance improves significantly with copper pour or short lead lengths-enabling 1 A RMS operation at T_lead ≤51.2 °C per Figure 5.

Does BT131-800D require a snubber circuit in standard 230 VAC dimmer applications?

BT131-800D supports snubberless operation in many 230 VAC resistive and lightly inductive loads due to its minimum dV/dt rating of 20 V/μs at 125 °C (Table 5). However, snubbers remain recommended for highly inductive loads (e.g., transformers, solenoids) or environments with severe line noise-where dV/dt may exceed 50 V/μs during commutation.

What is the non-repetitive peak on-state current (I_TSM) for BT131-800D at 16.7 ms?

The BT131-800D supports a non-repetitive peak on-state current (I_TSM) of 13.7 A for a 16.7 ms half-sine pulse (50 Hz cycle) at T_j = 25 °C prior to surge (Table 3). This rating enables robust handling of motor startup surges and heater inrush currents without latch-up or thermal runaway-provided lead temperature remains within limits.