Precision reference for sensitive analog rails
The ISL21090BFB812Z-TK is a series voltage reference from Renesas, delivering a fixed 1.25V output with ±0.03% initial accuracy and a temperature coefficient of 7ppm/°C.
Noise floor that doesn't limit the signal chain
Output noise is specified at 1µVp-p in the 0.1Hz to 10Hz band and 1.2µVrms from 10Hz to 10kHz. For a 16-bit ADC with a 2.5V reference, the noise contribution from the reference alone sits well below 1 LSB — the reference won't be the dominant noise source in the chain. Input voltage range spans 3.7V to 36V, so the reference can run from a 5V rail or a 24V industrial supply without a preregulator. Output current is rated 20mA, enough to bias multiple ADC inputs or a small sensor bridge. Supply current is 1.28mA typical — low enough that the reference's own draw doesn't dominate the power budget in a multi-rail system.
Active production, ROHS3, standard SOIC footprint
It is ROHS3 compliant, so it clears EU and global regulatory gates without an exemption. Packaged in an 8-SOIC (0.154" width, 3.90mm body) — a standard surface-mount footprint that reflows on any lead-free profile.