In modern 48V / 12V automotive systems in Zone Control Module and 12V/48V Power Distribution Box, common application utilizes GaN based power stage designs, high power buck/boost, and half-bridges for zonal power architectures. In this architecture, the power stage and the gate driver often operate in a local reference domain that can move relative to the system/MCU ground. This creates a practical challenge as the control signals from system microcontroller (MCU) for the gate drivers (PWM/enable pins) are referenced to logic ground, but the GaN gate driver input pins (bootstrap/bias) can be referenced to a different floating ground. Further, the fast switching edges and high dV/dt at the half-bridge switch node can also inject ground noise.

As shown in Figure 3-1, the TXG8020-Q1 or TXG8010-Q1 helps to partition the noisy power ground at gate-driver domain from the quiet logic ground at MCU domain. The MCU drives digital I/O (PWM/EN) into TXG’s A-side inputs, and the corresponding B-side outputs reproduce those signals referenced to the GaN driver domain with clean logic transitions. Key design notes:

• Domain definition matters: GNDA (quiet logic) and GNDB (driver local/switching) must be planned early so the PWM reference is correct where it terminates.
• Local decoupling on both rails: Decouple VCCA and VCCB close to the TXG device.
• Signal integrity: Keep PWM traces short, control return paths, and avoid routing B-side signals through noisy switch-node regions.
• Scalability: TXG offers 4-channel, 2-channel as well 1-channel options to level shift multiple related control signals (for example, PWM, enable, reset, interrupt) as well as popular digital interaces, reducing glue logic.