The TPS2553DDBVT is a single-channel high-side power switch from Texas Instruments, built around an N-channel MOSFET with a typical on-resistance of 85 mOhm. At the rated 1.5 A continuous output, that resistance drops about 128 mV across the switch — a figure that matters when the downstream load has a tight undervoltage lockout threshold.
Slew rate control and adjustable current limit
Slew rate control limits the output voltage rise time during turn-on, reducing inrush current into capacitive loads. The current limit is adjustable via an external resistor, letting the designer set the trip point below the 1.5 A maximum to protect the load or the wiring. A status flag output asserts low when the switch is in current limit or thermal shutdown, providing a clean fault signal to a GPIO or system monitor.
150°C junction — package thermal reality
The junction temperature range extends to 150°C, which qualifies the part for under-hood automotive and industrial enclosure environments. At 1.5 A continuous, the 85 mOhm Rds(on) dissipates about 190 mW — within the package capability at 85°C ambient with reasonable board copper, but the margin shrinks at elevated ambient temperatures. The over-temperature protection provides a safety net.
Protection set: UVLO, over-temperature, adjustable limit
Undervoltage lockout (UVLO) holds the switch off until the input voltage rises above the minimum operating threshold, preventing the MOSFET from operating in the linear region. Over-temperature protection shuts down the switch if the die exceeds the thermal limit, with automatic recovery after cooling. The adjustable current limit, set by a resistor to ground, allows the designer to tailor the trip point to the specific load — useful for powering USB ports, sensors, or peripheral rails where the fault current must be clamped below the supply's capacity.