Renesas launches highly commutative triode bidirectional thyristor switching devices

     Renesas Electronics has announced the BCR8LM-14LK, A highly commutative tridirectional triac switching device that supports rated on-state current RMS (IT (RMS)) 8 amps (A) and rated off-state Repeat peak voltage (VDRM) 700 volts, which can be triggered directly by a single chip microcomputer (MCU). The new three-terminal bidirectional thyristor switching device can be used to drive loads such as AC motors, solenoid valves and heaters in household appliances (white goods) such as washing machines and refrigerators.

     Triac switching devices are used to control power switches in AC circuits. Due to the high gate trigger current (IGT), a dedicated circuit is required to amplify the output current of a traditional MCU. Reducing gate trigger current usually comes at the expense of other performance. The BCR8LM-14LK maintains the performance of existing TRIAC products while achieving a low gate trigger current of 12 milliamps (mA) or less, allowing it to be driven directly via an MCU. This eliminates the need for amplifying circuits previously required, making it possible to design more compact, lower-cost drive circuits with fewer components and lower power consumption.

     In the field of household appliances (white goods), the demand for smaller, more power-efficient drive circuits for loads such as AC motors, solenoid valves and heaters has increased in recent years due to design and energy efficiency considerations. This has led to the need for three-terminal bidirectional thyristor switching devices that can be driven directly by MCU without a dedicated driver circuit.

     However, the gate trigger current of three-terminal bidirectional thyristor switching devices is usually 30 MA or higher. Reducing the gate trigger current to around 12 mA to accommodate the low current output of a typical microcontroller results in a deterioration of the commutation characteristics and the off-state critical voltage rise rate (dv/dt), which is important to prevent failure. The BCR8LM-14LK uses a basic structure designed to reduce gate trigger currents and utilizes special device architecture and process optimization to achieve gate trigger currents of only 12 mA or less without compromising other important characteristics of the TRIAC.

     The BCR8LM-14LK device is the industry's first three-terminal bidirectional thyristor switching device with a voltage tolerance in the 700 volt class, maintaining high commutation of ((dv/dt)c) 10 V/µs while achieving gate trigger currents of 12 mA or less. Unlike traditional three-terminal bidirectional thyristor switching devices, the BCR8LM-14LK does not require a dedicated drive circuit. As a result, systems such as AC motors can use simpler drive circuits, which helps reduce component costs and power consumption.

     In addition to the BCR8LM-14LK device with a rated on-state current RMS of 8 AmPs, Renesas also plans to introduce new products with 12 AmPs, 16 AmPs and 20 AmPs to further expand the product lineup of this family. In addition TO the TO-220FL (UL certified) insulated package, Renesas Electronics will offer a range of non-insulated packages to meet a wide range of customer needs.