The BT137S-600D is a four-pin surface-mounted Triac made by NXP Semiconductors. It is designed for switching and phase control applications such as motor speed control, lamp dimming, and industrial heaters. It has maximum ratings of 600V, 8A, and a snubberless trigger voltage of 1.6V. It is available in TO-92 and surface-mount packages, and is compatible with industry-standard control and gate driver ICs. It has low gate current and low on-voltage, and operates over a wide temperature range.