What this USB power switch does for your design
The TPS2546RTER is a single-channel high-side N-channel USB power switch from Texas Instruments, rated for continuous output up to 3A with a typical on-resistance of 73mOhm. That Rds(on) means at 3A you're dissipating roughly 0.66W in the switch — the exposed pad on the 16-WQFN (3x3 mm) package is your primary thermal path, so the board copper under it needs to be there. It operates from a 4.5V to 5.5V load supply — essentially a 5V rail — and requires no separate Vcc supply. The On/Off interface with non-inverting input lets a GPIO or open-drain signal enable the output.
Protection scheme that handles real USB faults
Built-in fault protection includes an adjustable current limit — you set the threshold with an external resistor, giving flexibility from a few hundred mA up to the 3A ceiling. Over-temperature shutdown and undervoltage lockout are also on-chip, so a shorted cable or a hot-plug surge won't take out the rail or the part. The 1:1 input-to-output ratio means the switch is a straight pass element — no charge pump needed, which keeps the quiescent current low and the response fast.
Active production — sourcing for your BOM
No end-of-life notification or successor has been issued.
Package and thermal considerations for layout
Without that copper pour, the junction temperature rises quickly at 3A continuous. The surface-mount package is standard for reflow assembly.