Active production — no last-time-buy clock
The LT1004ID-2-5: This is not a phase-out line; you can design it into a new BOM without worrying about a forced last-time-buy window.
2.5 V shunt reference — the ±0.8% tolerance and the load ceiling
The LT1004ID-2-5 is a shunt voltage reference with a fixed 2.5 V output and ±0.8% initial tolerance. That 20 mV worst-case spread at 25 °C — for a 12-bit ADC with a 2.5 V reference, the reference error alone consumes about 3.3 LSBs of the accuracy budget before any converter INL or temperature drift. If your system needs tighter than 0.8%, a series reference like the LM4132 (0.05%) is a different topology and pinout; the board spins. The shunt can source or sink up to 20 mA while holding regulation. The practical load limit is lower once you subtract the minimum cathode current of 20 µA — the resistor that biases the shunt must supply both the load current and the reference's own bias. If the total current through the shunt drops below 20 µA, the reference falls out of its specified regulation band. Temperature drift is 20 ppm/°C typical. For a 10-bit ADC that is roughly 2.5 LSBs; for a 16-bit ADC it is 40 LSBs — the drift dominates the error budget at high resolution unless the system is calibrated at temperature.
This is the integrated noise that lands on the reference node; a 16-bit SAR converter sampling at 100 kS/s sees this as roughly 3.2 LSBs of peak-to-peak noise (assuming 6.6× crest factor). If the application needs sub-LSB noise performance, a low-pass filter after the reference output or a lower-noise reference is required.
8-SOIC footprint — standard land pattern, tube delivery
The supplier device package is 8-SOIC. The land pattern is the standard SOIC-8 footprint — same pads as a generic op-amp or comparator. No special stencil aperture or reflow profile beyond the JEDEC standard for a 1.27 mm pitch SOIC.
ROHS3 compliance — no exemption-listed substances
Texas Instruments certifies the LT1004ID-2-5 as ROHS3 Compliant. This means no decaBDE, no phthalates above the threshold, and no RoHS exemption-listed substances. Relevant for EU RoHS and China RoHS declarations at the finished-good level.