Reset supervisor for a 5V rail — what the 4.55V threshold means
The TPS3801I50DCKR: That threshold is set for a nominal 5 V supply — it trips when the rail drops to about 91% of 5 V, giving the downstream processor a clean reset before the logic levels go indeterminate. The output is push-pull, totem-pole, active low — no external pull-up resistor needed. It drives the reset input of an MCU, FPGA, or DSP directly. The SC-70-5 package (also known as SOT-353) is a 5-pin surface-mount package that fits tight board layouts.
The SC-70-5 footprint is shared with many other TI reset supervisors — if you have a board already laid out for a TPS380x or TPS382x in the same package, this part drops in without a layout change. The 5-pin SOT-353 land pattern is standard; no exotic pad geometry.