What the OP113EP is and where it fits
The Analog Devices OP113EP is a single-channel general-purpose operational amplifier in an 8-pin PDIP package. It delivers a 3.4 MHz gain-bandwidth product and a 1.2 V/µs slew rate. The industrial temperature range (-40°C to 85°C) covers factory-floor cabinets, outdoor telecom shelters, and under-hood automotive sensor interfaces. Through-hole PDIP package suits prototyping, legacy board repairs, and low-volume builds where hand-assembly or socketing is preferred.
Key ratings and what they mean for the BOM
Input offset voltage is 75 µV and input bias current is 240 nA — both moderate figures. For a precision weigh-scale or thermocouple amplifier, you would want lower offset (e.g., 15 µV from the ADA4077-1ARZ-R7), but for general-purpose signal conditioning, motor-current sensing, or set-point comparators, these numbers are adequate and keep the BOM cost down.
Lifecycle and sourcing reality
For dual-sourcing or a surface-mount alternative, the ADA4077-1ARZ-R7 is a close functional peer: same 3.6 MHz GBW, same 1.2 V/µs slew rate, but with 15 µV offset and 400 pA bias — better DC precision — in an SOIC-8 package. The trade-off is surface-mount only and a narrower 5 V supply typical.