The OPA835 and OPA2835 from Texas Instruments are single and dual ultra-low-power, rail-to-rail output, negative-rail input, voltage-feedback (VFB) operational amplifiers designed for optimal performance in battery-powered and portable systems. Operating over a power supply range of 2.5 V to 5.5 V, these op amps consume only 250 µA per channel and offer a unity gain bandwidth of 56 MHz, making them industry leaders in performance-to-power ratio for rail-to-rail amplifiers. These components feature a quiescent current of 250 µA/ch (typical), with a power-down mode reducing current to 0.5 µA (typical), a slew rate of 160 V/µs, a rise time of 10 ns for a 2 V step, and a settling time of 55 ns to 0.1% for a 2 V step. Additional features include a signal-to-noise ratio (SNR) of 0.00015% (-116.4 dBc) at 1 kHz (1 VRMS), total harmonic distortion (THD) of 0.00003% (-130 dBc) at 1 kHz (1 VRMS), and a wide input voltage noise of 9.3 nV/√Hz at 100 kHz. The OPA835 and OPA2835 provide rail-to-rail output swing and input voltage range from -0.2 V to 3.9 V (5-V supply), supporting high-density, low-power signal conditioning applications with an operating temperature range from -40°C to +125°C. These components come in various package options, ensuring flexible integration into diverse electronic designs.