Low-side switch with integrated protection — the 700 mOhm conduction loss floor
The BTS3205NHUSA1 is an N-channel low-side power distribution switch from Infineon's HITFET series, designed for general-purpose on/off control of resistive and inductive loads up to 350 mA continuous at a load voltage of 42 V max.
Fault protection set — current limit, over-temp, over-voltage
The On/Off interface is non-inverting with a 1:1 input-to-output ratio, and no external Vcc supply is required — the internal charge pump derives gate drive from the load voltage itself.
Package and board-fit — SOT223-4 footprint
Housed in the PG-SOT223-4 package (TO-261-4, TO-261AA), the BTS3205NHUSA1 mounts with a standard SOT223 land pattern — the tab is the drain connection and carries the heat into the board copper. The 350 mA continuous output is well within the SOT223 thermal capability at 85 °C ambient with 1 oz copper, but the tab pad should be stitched to a ground plane pour for the 150 °C junction limit under fault conditions.
The base product number BTS3205 identifies the family; the NHUSA1 suffix denotes the specific SOT223-4 variant and tape-and-reel packaging.