Hall-effect current sense for 3V to 5.5V rails
The TMCS1108A3UQDT is a unidirectional Hall-effect current sensor from Texas Instruments that outputs a ratiometric voltage proportional to the sensed AC or DC current. It is built for surface-mount assembly in the compact 8-SOIC package, making it a fit for dense PCB layouts where a current-sense resistor and isolated amplifier would take up more board area.
What the 200 mV/A sensitivity and 80 kHz bandwidth mean on the bench
The sensitivity of 200 mV/A means that for every ampere of current through the conductor, the output voltage shifts by 200 mV. With a 3.3 V supply and a 12-bit ADC, the LSB size is about 0.8 mV, giving you roughly 4 mA of current resolution per code — enough for load monitoring in a motor drive or a battery charger, but not for microamp-level leakage detection. The 80 kHz bandwidth and 6.5 µs response time tell you this sensor can track switching waveforms up to about 80 kHz before the output amplitude starts to roll off. That covers the fundamental ripple frequency of most SMPS designs running at a few hundred kHz, but you will see attenuation on the switching edges themselves. For a 100 kHz switching regulator, the output will be a smoothed version of the actual current waveform. Linearity is spec'd at ±0.5% — this is the deviation from a straight line through the full-scale output. In practice, it means the reading at 5 A will be within 0.5% of the ideal value, assuming the offset is zeroed out. The ratiometric output means the scale factor tracks the supply voltage, so if your 3.3 V rail drifts by 1%, the sensitivity drifts by the same 1% — something to account for if the ADC reference is not also ratiometric.
Supply range, temperature, and package realities for the BOM
Operating from a 3 V to 5.5 V supply, the TMCS1108A3UQDT draws a maximum of 6 mA — under 20 mW at 3.3 V, so self-heating is negligible. The -40°C to +125°C ambient temperature range covers industrial and automotive under-hood environments, but note that the Hall element's offset drifts with temperature; the datasheet's offset drift spec (not in this record) is the number to check for a precision application across temperature. The 8-SOIC package (3.90 mm width, 0.154-inch body) is a standard footprint that reflow-solders without special profiling. The device is surface-mount only — no through-hole variant exists in this family. The supplier device package is listed as 8-SOIC, which is the same as the package/case entry, so no ambiguity on the footprint.
Active production and how to source it
Sourced to order against your BOM quantity through independent and authorized distribution channels.