Function and fit — a legacy decade counter for repair and MRO
The 54F190LMQB is a decade counter. It is a member of the 54F logic family, designed for high-speed counting in military-temperature-range systems. Typical applications include frequency dividers, industrial timers, and sequential logic in avionics or ground-support equipment where a BCD output is required.
RoHS non-compliance — a BOM constraint
This part is RoHS non-compliant. Any design or repair BOM that requires RoHS conformance must use a lead-free alternative. For legacy military or aerospace assemblies that are exempt from RoHS requirements, the 54F190LMQB remains a valid, directly compatible drop-in. Verify your project's environmental compliance scope before ordering.
Package and sourcing reality
This is a legacy packaging format; it is not Tape & Reel. For repair depots or MRO shops stocking a single line item, Bulk is straightforward. For high-volume pick-and-place, you will need to evaluate handling separately.