Dual high-side switch with adjustable current limit
The TPS2561ADRCT is a dual-channel high-side power switch from Texas Instruments, designed to distribute power to USB ports, peripheral loads, and general-purpose 2.5 V to 6.5 V rails. Each of the two N-channel outputs delivers up to 2.5 A continuous, with a typical on-resistance of 44 mOhm — the conduction loss at 2.5 A is roughly 275 mW per channel, which the 10-VSON exposed pad must sink to the board. The switch is self-contained: no external Vcc supply is needed, and the On/Off interface accepts a non-inverting logic signal. The slew-rate controlled turn-on limits inrush current, and the open-drain status flag reports overcurrent or thermal fault conditions.
Parametric fit: Rds(on), input range, and protection
The 44 mOhm typical Rds(on) at 2.5 A sets a voltage drop of roughly 110 mV per channel — low enough to keep a 5 V USB rail above the 4.75 V minimum under full load. The load voltage range of 2.5 V to 6.5 V covers 3.3 V and 5 V rails, and the device does not require a separate bias supply. Fault protection includes adjustable current limiting (set with an external resistor), over-temperature shutdown, and undervoltage lockout. The 1:2 input-to-output ratio means a single enable signal gates both channels simultaneously — useful for ganged power domains.
Package, temperature grade, and sourcing posture
The 10-VSON package (3x3 mm, 0.50 mm pitch) with exposed pad requires a thermal land on the PCB — the datasheet recommends a 2.8x2.8 mm pad with at least four thermal vias to the ground plane.