The Maxim Integrated ICL7137CPL+ is a 3.5-digit display driver in a 40-pin DIP package. It takes an analog input and drives a common-cathode LCD or LED display directly, with no external active components needed for the display interface. The single-supply operation simplifies the power rail — just one positive supply, no negative rail required. This part is the standard choice for panel meters, digital voltmeters, temperature indicators, and other instruments where a clear numeric readout is needed and board space is not a constraint.
The 3.5-digit resolution means the display shows a full-scale reading of ±1999 counts. That gives you a 0.05% resolution at full scale — enough for a 4-digit panel meter reading voltage, current, or temperature with a clear last digit. For applications that need 0.01% or better, you would step up to a 4.5-digit driver, but for the vast majority of industrial panel meters and benchtop instruments, 3.5 digits is the workhorse resolution.
Package and assembly — through-hole, no surprises
The 40-DIP (0.600", 15.24mm) through-hole package is a standard footprint that has been in production for decades. It is socket-friendly for prototyping and field service, and it survives hand-soldering without thermal concern. The 40-PDIP supplier device package is the same body. No moisture sensitivity level to track — store the tubes on the shelf as-is.
Not rated for outdoor or under-hood automotive use where the ambient goes below freezing or above 70°C.