2.048V ±0.1% — the precision floor for your ADC reference rail
The LM4140CCM-2.0/NOPB is a series voltage reference from Texas Instruments, fixed at 2.048V output with ±0.1% initial tolerance. That 2.048V value is a deliberate choice — it matches the common 0–2.048V or ±2.048V input range of many precision ADCs, so the full-scale reading lands cleanly without gain scaling. The series topology means the reference draws a constant 375µA supply current regardless of load, unlike a shunt reference that burns current through a bias resistor. For battery-powered instruments that stay in sleep mode most of the time, that quiescent current matters more than the dropout headroom.
Noise and drift — the two specs that decide signal-chain accuracy
Noise is specified at 2.2µVp-p from 0.1Hz to 10Hz — the band where flicker noise dominates. For a 16-bit ADC with a 2.048V reference, the LSB is about 31µV, so this reference's peak-to-peak noise is roughly 7% of one LSB. That means the reference contributes negligible noise to the conversion result in most precision applications. Temperature coefficient is 10ppm/°C, which translates to 20.5µV per degree Celsius at the 2.048V output. A system that calibrates at room temperature and operates across the full range needs to budget this drift into the accuracy specification. Output current is rated at 8 mA, which is enough to drive the reference input of most ADCs (typically 1–5 mA) plus a small resistive divider if needed.
ROHS3 compliant with no exemptions — the /NOPB suffix confirms lead-free plating on the leads. No restricted substance declarations to manage in your BOM compliance report.
8-SOIC — the standard footprint for precision references
The 8-pin SOIC (0.154-inch body width, 3.90mm) is the most common package for voltage references in this performance class. The footprint is industry-standard — any 8-SOIC land pattern from your PCB library will work. The tube packaging means it ships in standard anti-static tubes of 95 units per tube, not tape-and-reel, so it's suited for hand-assembly or low-volume production.