SBAA793 March 2026 TXG1020-Q1 , TXG1021-Q1 , TXG1041-Q1 , TXG1042-Q1 , TXG4020-Q1 , TXG4021-Q1 , TXG4041-Q1 , TXG4042-Q1 , TXG8010-Q1 , TXG8020-Q1 , TXG8021-Q1 , TXG8041-Q1 , TXG8042-Q1 , TXG8122-Q1
- 1
- Abstract
- Trademarks
- 1Introduction: The Automotive Ground Reality
- 2Automotive Ground-Level Voltage Translation (TXG) Portfolio
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3Automotive Application Examples using TXG
Ground-Level Translators
- 3.1 Bridging Logic and Power Domains in 48V / 12V Automotive Systems
- 3.2 Simplifying Automotive Media Hub and USB Charging
- 3.3 Robust Battery Monitoring in 48V Automotive Systems
- 3.4 Simplifying Multiboard I/O Design
- 3.5 Automotive Audio Systems
- 3.6 Redundant Safety for Electrical Power Steering Subsystem
- 3.7 Robust IGBT Temperature Telemetry across Ground Domains
- 3.8 Mitigating Ground Bounce in Single-Ended Interfaces
- 3.9 Reliable Communication in ADAS Camera
- 4When to Use TXG vs. Galvanic Isolation
- 5Getting Started
- 6Summary
- 7References
3.2 Simplifying Automotive Media Hub and USB Charging
In modern automotive Auxiliary Systems for multiport USB hub design, each USB PD controller operates from its local VBUS-referenced ground, while the central MCU resides in a separate 3.3V logic domain. Because ground offsets can exist between these domains, directly connecting the I2C lines can degrade noise margin and compromise communication reliability.
The TXG8122-Q1 is used as a bidirectional I2C ground-level translator between each PD controller and the MCU as shown in Figure 3-2. By tying one side to the PD controller’s local supply/ground and the other side to the 3.3V domain of the MCU, the device re-references SDA and SCL to the appropriate ground while maintaining compliant logic thresholds. This enables robust multidomain I2C communication without requiring galvanic isolation, simplifying the overall power and interface architecture.
Figure 3-2 Block Diagram for Automotive
Media Hub and USB Charging Using TXG8122-Q1