What this P-channel switch does on the board
The Microchip MIC94064YC6TR is a single-channel, high-side P-channel MOSFET load switch designed for general-purpose on/off control of power rails. The switch is slew-rate controlled, meaning the output voltage ramps up gradually when the enable pin is asserted. This limits inrush current into downstream capacitive loads — a common requirement when switching a bank of decoupling capacitors or powering up a sensor module that presents a large input capacitance. No external Vcc supply is needed — the switch is self-powered from the load rail.
At 2 A, the 77 mOhm typical Rds(on) produces a conduction loss of about 310 mW (I²R). In the SC-70-6 package, that heat must be dissipated through the copper traces and the board — the junction-to-ambient thermal resistance is not specified here, but a 2 A continuous load on a 0.65 mm pitch package demands a solid ground-plane pour under the part and adequate via stitching to lower the thermal resistance. Compared to the MIC2097-1YMT-TR and MIC2019A-2YM6-TR, which carry a 170 mOhm Rds(on), the MIC94064YC6TR cuts the conduction loss by more than half at the same current. That difference matters when the switch is the only thermal bottleneck on a tightly packed board.
Temperature rating and deployment environment
The MIC2019A-2YM6-TR, by contrast, is only rated to 85°C, so this part is the one to specify for extended-temperature designs.
Package and footprint — SC-70-6
The switch comes in a 6-lead SC-70 (SOT-363) package, also designated as the supplier device package SC-70-6. The 0.65 mm lead pitch and compact body (roughly 2.0 mm x 2.1 mm) make it a fit for space-constrained PCBs in handheld instruments, IoT nodes, and portable medical devices. The surface-mount package reflows on standard lead-free profiles.
For dual-sourcing planning, the MIC2097-1YMT-TR offers a 170 mOhm alternative with adjustable current limiting and UVLO, though at a higher Rds(on).