What the OPA391DCKR is and where it fits
The Texas Instruments OPA391DCKR is a single-channel, general-purpose CMOS op-amp from the e-trim™ series, housed in a 5-pin SC-70-5 (SOT-353) package for surface-mount assembly. It delivers a 1 MHz gain-bandwidth product with a 1 V/µs slew rate, rail-to-rail output swing, and an input offset voltage trimmed to 15 µV. The part operates from a 1.7 V to 5.5 V supply span, drawing only 24 µA quiescent current. With its -40°C to 125°C temperature range, this op-amp is suited for industrial sensor interfaces, battery-powered instrumentation, and portable medical devices where low power and precision matter.
Key ratings and what they mean for the BOM
The 15 µV input offset voltage is the part's precision anchor — it eliminates the need for external nulling in dc-coupled stages, saving board space and trim components. The 0.01 pA input bias current means negligible voltage drop across high source impedances, making the OPA391DCKR a natural fit for photodiode transimpedance amplifiers or electrochemical sensor front-ends. The 24 µA supply current keeps the power budget tight in always-sensing nodes; at 1.7 V minimum supply, the part can run directly from a single lithium coin cell without a boost converter. Rail-to-rail output preserves signal swing at low supply rails, critical for single-supply ADCs with full-scale inputs. The 60 mA output current capability gives enough drive for reference buffers or small relays.
Packaging and mounting
The SC-70-5 (SOT-353) footprint is a compact 5-lead package. Surface-mount assembly fits standard reflow profiles.
Lifecycle and sourcing
The OPA391DCKR is listed as Active with no end-of-life notification. That means it remains a current-production line item for new designs. For dual-sourcing flexibility, the TLV9351IDCKR is a functional alternative in the same SC-70-5 package — it offers a wider 3.5 MHz GBW but draws 600 µA supply current, so the trade-off is bandwidth versus power. The OPA391DCKR is sourced and quoted to order through independent distribution; availability and current pricing are confirmed at quote time.