LM615AIN

Overview

The LM615AIN is a quad comparator and adjustable voltage reference integrated circuit manufactured by Texas Instruments, originally from National Semiconductor. It features four comparators with lateral PNP input transistors for low input currents and wide differential input voltage tolerance up to 36V. The device includes a three-terminal shunt-type band-gap reference with an initial accuracy of ±0.6% at 25°C. Operating over an industrial temperature range of -40°C to +85°C, it supports supply voltages from 4V to 36V with a maximum total supply current of 600mA.

Feature Summary

• Integrates four high-speed comparators with open-collector outputs and lateral PNP input stages capable of handling large differential input voltages.
• Includes a precision adjustable band-gap voltage reference with tight initial tolerance and wide capacitive load stability.
• Supports a wide single-supply voltage range from 4V to 36V with low operating current consumption.
• Features an input common-mode range extending to the negative supply rail.

Applications

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

Procurement Notes

Verify that the ordering suffix 'AIN' corresponds to the specific industrial temperature grade (-40°C to +85°C) and ±0.6% reference tolerance as defined in the manufacturer's ordering information. Confirm package compatibility with the 16-pin molded DIP (N16A) footprint. Ensure design accounts for open-collector output requirements necessitating external pull-up resistors for proper logic level switching.

Selection Notes

Select this component when a combined solution for multiple comparisons and a stable reference voltage is required to reduce board space. It is suitable for applications needing inputs that swing above the positive supply rail without damage. Consider the 600mA maximum supply current and thermal resistance characteristics for power dissipation management in enclosed environments.

Part Context

The LM615 belongs to the Super-Block family, designed as a monolithic alternative to multi-chip solutions. It combines comparator and reference functions typically found in separate components. The device was originally produced by National Semiconductor before its acquisition by Texas Instruments, maintaining legacy part numbering conventions.

Replacement Considerations

LM615AMJ/883: Ceramic DIP military grade variant with extended temperature range.

FAQ

What is the input common-mode voltage range for the comparators?

The guaranteed common-mode input voltage range extends from the negative supply (Vb) to (Va - 1.8V).

How is the reference output voltage adjusted?

The reference output voltage can be programmed from 1.24V to 6.3V using two external resistors connected to the FEEDBACK pin.

Can the inputs handle voltages higher than the positive supply?

Yes, the lateral PNP input transistors allow for large differential input voltages up to 36V, even if one input exceeds the positive supply voltage, provided the other input remains within the common-mode range.