USB power-rail switch — 500 mA high-side with fault reporting
Output configuration is high-side with a 1:1 input-to-output ratio, so the switch sits between the supply rail and the load with no external charge pump needed. Rated for a continuous output current of 500 mA, the LM3525M-L covers a single USB downstream port or a dedicated charging channel. The 80 mOhm typical on-resistance keeps conduction loss under 20 mW at full load, which is low enough to avoid thermal derating in the 8-SOIC package at 85°C ambient. No separate Vcc/Vdd supply is required — the switch is self-powered from the load voltage pin.
Fault protection set and status flag
Built-in fault protection includes fixed current limiting, over-temperature shutdown, and undervoltage lockout (UVLO). The current limit is fixed internally — no external resistor sets the trip point — so the switch self-limits to a safe level during a short circuit or heavy capacitive load. The status flag output (open-drain, active low) asserts when a fault condition is detected — over-current, over-temperature, or UVLO. This flag can drive a GPIO on the host controller or a discrete LED, giving the system a real-time indication that the port has been disabled. Input type is non-inverting with an On/Off interface: a logic high on the enable pin turns the switch on. The output is a P-channel MOSFET, so the switch is active-high and the output follows the input when enabled.
The supplier device package is listed as 8-SOIC, so the PCB layout is identical to any generic SO-8 power switch. The tube packaging is typical for prototype and low-volume assembly; for reel quantities, check the alternate ordering options.
Lifecycle and compliance
No official successor or pin-compatible second source is listed in the manufacturer records. For BOM hedging, the parametric fit is narrow — fixed current limit, P-channel high-side, SO-8 — so a direct drop-in from another vendor would require a board spin or a change in the current-limit behaviour.