The MIC281-4YM6-TR is a digital remote temperature sensor from Microchip Technology's IttyBitty™ series, sensing temperature from an external diode-connected transistor and reporting it over an I²C/SMBus interface. The SOT-23-6 package (supplier device package SOT-23-6) means a 0.95 mm pitch footprint with six leads — the PCB layout needs a thermal via under the GND pad to pull heat from the die, and the remote diode traces should be kept short and guarded to avoid noise injection into the sense current. The 7-bit resolution gives 128 temperature steps; the datasheet's conversion formula maps each LSB to roughly 1°C, which is adequate for over-temperature protection and fan control but not for precision thermal compensation of an oscillator or ADC reference.
Shutdown mode and remote sensing — deployment context
The shutdown mode feature lets the sensor enter a low-power state between temperature readings — useful in battery-powered or thermally constrained designs where the sensor only needs to wake periodically to check for over-temperature conditions. The remote sensing range covers -55°C to 125°C, matching the operating temperature of the sensor itself — this means the external diode can be placed on a hot component (CPU core, power MOSFET, LED array) while the MIC281 stays on the main board at ambient temperature. The I²C/SMBus output allows daisy-chaining multiple sensors on the same two-wire bus — each MIC281 has a unique address set by the pin strapping, so up to eight devices can share the bus without a multiplexer.