Transimpedance front-end in an 8-VSSOP
The OPA2381AIDGKT: Its 18 MHz gain-bandwidth product and 12V/µs slew rate let it handle fast optical pulses from avalanche photodiodes or high-speed PIN diodes, while the 3 pA input bias and 7 µV input offset keep the dark-current error and DC baseline drift low enough to skip a trim pot in many designs. The 8-VSSOP package keeps the photodiode and feedback components close, minimising parasitic capacitance at the summing node.
800 µA per channel — sizing the power rail
Each amplifier draws 800 µA supply current, so the dual channel OPA2381 consumes 1.6 mA total at no load. In a battery-powered photodiode receiver or an optical smoke detector that runs 24/7, that quiescent current lands in the right budget tier — not the sub-µA micropower class, but well below the 2 mA to 3 mA per channel a general-purpose 18 MHz op-amp would burn. The 10 mA output current per channel can drive a 50 Ω load or a moderate ADC input directly.
Rated across the full industrial temperature span, the OPA2381AIDGKT is specified for outdoor telecom enclosures, under-hood optical sensors, and process-control photodetectors.