5V fixed rail for 12V automotive sensor modules
The TLE42644GHTSA3 is a single-output, 5V fixed LDO from Infineon's OPTIREG™ family, qualified to AEC-Q100 for automotive use. It delivers 100mA continuous output from a 40V max input, with a maximum dropout of 0.5V at full load. A 68dB PSRR at 100Hz knocks down the dominant alternator ripple frequency, keeping a clean 5V rail for sensor analog supplies or MCU ADC references.
Dropout headroom and quiescent draw for always-on rails
At 100mA the maximum dropout is 0.5V, so the input can sag to 5.5V before the output loses regulation — useful during cold-crank events where the battery dips below 6V. Quiescent current is 60µA typical, keeping the regulator's own draw low for ignition-off or battery-backed loads. Built-in protections — over-current, over-temperature, reverse polarity, and short-circuit — reduce the need for external clamp diodes or resettable fuses on the output.
Active lifecycle — no obsolescence watch for new BOMs
The part is ROHS3 compliant and supplied in tape-and-reel or cut-tape options for the PG-SOT223-4 package.
Package and footprint — SOT223-4 rework notes
The PG-SOT223-4 (TO-261AA) package has a large exposed tab on the bottom for thermal dissipation. The tab is the output (VOUT) potential, so the PCB copper pour under it must be connected to the output net, not ground. Confirm the orientation against the datasheet before reflow; the tab's large thermal mass means the hot-air station needs a few extra seconds to reflow the joint without lifting adjacent pads.