USB power switch with adjustable current limit and overvoltage protection
The Texas Instruments TPS2549RTER is a single-channel, high-side N-channel USB power switch in a 16-WQFN (3x3 mm) package. It delivers up to 3 A continuous from a 4.5 V to 6.5 V load supply. The switch integrates adjustable current limiting, overvoltage protection (OVP), overtemperature shutdown, and undervoltage lockout (UVLO). A status flag output reports fault conditions. The load-discharge feature pulls the output low when the switch is off, preventing a floating VBUS that could confuse a connected device.
What the 47 mOhm Rds(on) and 3 A rating mean for the BOM
At 3 A, the 47 mOhm typical Rds(on) produces dissipation inside the 3x3 mm QFN. Heat exits through the exposed pad to the PCB copper. The adjustable current limit (set by an external resistor) lets you tailor the trip point below 3 A for smaller loads or cable protection. The overvoltage clamp protects downstream circuitry if the VBUS rail gets hit with a transient above 6.5 V — a real risk on long USB cables in industrial noise environments.
The ROHS3 compliance covers current EU and global solderability requirements.