5 V shunt reference for precision bias and ADC references
The Texas Instruments LM4040C50IDCKR is a precision shunt voltage reference with a fixed 5 V output, ±0.5% initial tolerance, and a low 80 µVrms noise spec over the 10 Hz to 10 kHz band.
The ±0.5% initial tolerance sets the absolute accuracy floor at 25°C; for a 5 V output, that is ±25 mV maximum deviation before temperature drift. The 100 ppm/°C temperature coefficient adds about 0.5 mV per 10°C shift, so a system spanning -40°C to 85°C sees up to ±6.25 mV additional drift from the 125°C span. The 80 µVrms noise is low enough for a 12-bit ADC reference with a 5 V full-scale — the noise contribution stays well under 1 LSB. Cathode current range is 95 µA minimum to 15 mA maximum. The shunt draws just enough current to maintain regulation; the designer sets the series resistor to bias the reference within that window across the full load and supply variation.
The LM4040C50IDCKR comes in a 5-lead SC-70-5 / SOT-353 package (supplier device package SC-70-5). The 0.65 mm pitch and 2.0 mm × 2.1 mm body footprint fit tightly on space-constrained analog boards.