Power Module Adds Matched Driver to 1200-V/160-A Bidirectional Switch

You’re undoubtedly familiar with power-switching devices such as the venerable and still very viable insulated-gate bipolar transistor (IGBT). An enhanced variation is the B-TRAN bipolar junction transistor from Ideal Power Inc. (Austin, Texas). It’s a four-quadrant IGBT-like power switch with ultra-low forward voltage and low switching losses that can be used in both unidirectional and bidirectional switching applications (Fig. 1).

1. Shown are the schematic symbol (a), B-TRAN device package (note the four terminals in contrast to the three of a standard IGBT) (b), and basic B-TRAN I-V characteristics (c).

The company maintains that its symmetric bidirectional operation reduces the number of components by 75% when compared to a conventional bidirectional switch using IGBTs and diodes.

Still, every switching power device needs a driver, so Ideal Power has introduced a more-integrated enhancement of the B-TRAN that responds to that reality. Its 1200-V/160A SymCool IQ is an intelligent power module (IPM) with internal driver for the B-TRAN unit, simplifying system design-in (Fig. 2).

2. The block diagram of the SymCool IQ module illustrates the integration of the driver and the B-TRAN device into a single package.

Applications include solid-state circuit breakers, battery-disconnect switches, Vienna rectifiers (if you’re not familiar with that term, they’re unidirectional, three-phase, three-switch, three-level PWM rectifiers), T-type inverters, and matrix converters.

This module enhancement not only provides the required drive, but also adds overcurrent protection, undervoltage protection, temperature sensing, and a dedicated fault-indicator (FLT) pin. In addition to the low losses, the module features low parasitic inductance and capacitance, supporting switching up to 35 kHz. Furthermore, the module’s package, at approximately 120 × 70 × 28 mm, reduces the thermal resistance while increasing its power density (Fig. 3).

3. The SymCool IQ module is a compact unit with favorable thermal and parasitic performance.

Datasheets are available to support the existing B-TRAN device and the just-announced SymCool IQ module. In addition, there’s an informative white paper, “B-TRAN – Device Structure, Performance and Applications,” which provides insight into the B-TRAN device and its claimed benefits. Another paper, “B-TRAN™ Applications and Benefits,” offers some market perspective along with hard and soft numbers.