The NXP BT149D is a fast-acting, bidirectional thyristor (SCR) in a surface-mount (SMD) package, designed for use as a snubber switch in applications such as power supplies and AC motor drives. The BT149D has an incredibly low on-resistance of just 0.16O and can switch large current levels of up to 9A. It operates both in AC and DC loading conditions, with a wide range of gate triggering levels, between 5V-14V. Its non-zero gate triggering current eliminates false triggering in high noise environments. The BT149D also features a high ambient temperature of up to 175°C, allowing for its use in extreme operating conditions. It is UL-recognized and has a long lifecycle and virtually zero switching losses.