LM615IM

Overview

The LM615IM is a quad comparator and adjustable voltage reference integrated circuit manufactured by Texas Instruments (formerly National Semiconductor). It features four comparators with lateral PNP input transistors, enabling low input currents and operation with differential input voltages up to 36V. The device includes an adjustable shunt-type band-gap voltage reference programmable from 1.24V to 6.3V using two external resistors. Operating on a single supply voltage ranging from 4V to 36V, the comparators utilize open-collector outputs. The unit is housed in a 16-pin narrow surface-mount package.

Feature Summary

• Integrates four high-speed comparators with lateral PNP input stages for low bias current and wide differential input voltage tolerance.
• Includes a three-terminal shunt-bandgap voltage reference with adjustable output voltage capability via external resistors.
• Features open-collector comparator outputs requiring external pull-up resistors for proper logic level switching.

Applications

• Adjustable threshold detectors
• Time-delay generators
• Voltage window comparators
• Power supply monitors
• RGB level detectors

Procurement Notes

Verify the manufacturer origin, as the LM615 was originally produced by National Semiconductor before its acquisition by Texas Instruments. Confirm that the specific part number corresponds to the industrial temperature range (-40°C to +85°C) and the 16-pin narrow surface-mount package. Ensure compatibility with legacy design requirements when integrating this component into modern systems.

Selection Notes

Select the LM615IM when a combined solution of multiple comparators and a precision voltage reference is required within a single package. This component is suitable for applications demanding wide supply voltage ranges and inputs capable of handling large differential voltages. Consider the open-collector output topology when designing interface circuits, as it necessitates external pull-up components to define the high logic state.

Part Context

The LM615 belongs to the Super-Block family, designed to provide high integration levels as a monolithic alternative to multi-chip solutions. It improves upon the earlier LM139 series by utilizing lateral PNP input transistors, which allow for lower input currents and better performance with large differential input swings. The device consolidates analog comparison and voltage regulation functions into one compact footprint.

Replacement Considerations

The LM139 is a comparable quad comparator without the integrated reference feature. For direct pin-compatible replacements, verify availability from current manufacturers holding rights to the original National Semiconductor designs. Ensure any substitute maintains the 4V to 36V supply range and open-collector output characteristics if system constraints require them.