Revolutionary 100V Bi-Directional GaN Transistor: Power Rail Switching Made Easy

Innoscience Technology has recently unveiled its latest innovation in the form of a 100V bi-directional GaN-on-silicon transistor. This transistor is designed to replace a pair of back-to-back mosfets for the purpose of turning a power rail on and off. The company envisions its application in various fields, including 48V or 60V battery management systems, high-side load switch applications in bidirectional converters, and switching circuits in power systems. Additionally, it can be utilized in home batteries, portable charging stations, e-scooters, and e-bikes.

The newly launched transistor, known as INV100FQ030A, features two drains, a gate, and no source connection. The drains are symmetrical, and there are no parasitic diodes from drain to drain. With a maximum on-resistance of 3.2mΩ (2.5mΩ typ, +5Vgate, 25A), it is capable of carrying 100A at 25°C.

This device is particularly suitable for switching the negative rail in a two-wire power supply. It functions by being "on" when the gate is 5V above either of the drains and "off" when the gate is negative with respect to both drains or at the same potential as one drain and negative of the other. Innoscience Technology provided Electronics Weekly with a detailed description of this functionality when it introduced its second-generation 40V symmetrical hemt.

The gate threshold of the transistor typically ranges from 800mV to 2.5V, with a typical value of 1.1V. The absolute maximum gate voltage is 6V, which is close to the normal turn-on voltage. Therefore, accurate gate voltage control is crucial for optimal performance.

In terms of ruggedness, the transistor can withstand up to 300,000 5ms 120V drain-to-drain pulses at the maximum operating temperature of 150°C. It has a minimum temperature rating of -40°C, and the junction-to-board thermal resistance is 1.92°C/W. Drain-to-drain leakage in either direction is typically 1µA (4µA max) when the gate is connected to one drain and the other drain is at +80V.

While the operating speed is not explicitly discussed, some gate dynamical characteristics are provided, including a 3.3nF input capacitance and a total gate charge of 90nC (50V, 25A, 5Vgate). The transistor is packaged in a compact surface-mount form factor measuring 4 x 6 x 0.85mm.