8-SOIC footprint, adjustable shunt regulation
The TL1431IDT is a three-terminal adjustable shunt voltage reference from STMicroelectronics, packaged in an 8-SOIC (0.154", 3.90 mm width) for surface-mount assembly. The reference type is shunt, meaning it operates as a programmable Zener diode — the output voltage is set by two external resistors and remains stable across load and temperature. The headline tolerance is ±0.4%, which defines the initial accuracy of the reference voltage at 25°C. For a 2.5 V nominal output, this translates to a maximum deviation of ±10 mV — tight enough for precision power-supply monitoring, A/D converter references, or feedback loops in isolated DC-DC converters where the setpoint error directly affects the output regulation.
Output range and drive capability
The output voltage is adjustable from a minimum of 2.5 V up to a maximum of 36 V, set by the external resistor divider ratio. The 100 mA output current rating defines the maximum cathode current the device can sink while maintaining regulation — this is the load-driving limit for the shunt configuration, not a source current. Minimum cathode current is 1 mA, which is the lowest operating current required to keep the reference in regulation. Below this threshold the device may not maintain its specified accuracy. The temperature coefficient is 100 ppm/°C, meaning the output voltage drifts by 0.01% per degree Celsius — at the full 105°C operating limit the drift from 25°C is roughly 0.8% of the set voltage, which is additive to the initial tolerance.
Active production, industrial temperature grade
RoHS3 compliance (2011/65/EU + 2015/863) is confirmed, with no exemptions declared. The 8-SOIC package is supplied in Tape & Reel (TR) or Cut Tape (CT) options, both standard for automated pick-and-place assembly.