STMicroelectronics LM339QT: A Versatile Low-Power Quad Comparator

The LM339QT from STMicroelectronics is a high-performance, low-power quad voltage comparator that is designed to operate over a wide range of voltages, from a single power supply of +2V to +36V or dual supplies of ±1V to ±18V. This device is commonly used in various applications such as limit comparators, simple analog to digital converters, pulse, square wave and time delay generators, and many other design solutions where precision voltage comparison is required.

Each of the four independent comparators in the LM339QT is designed to accurately compare voltages applied at its two input leads. The outputs are NPN transistor collectors, which provide a high level of compatibility with TTL and MOS logic families when used with pull-up resistors. The open-collector outputs also allow for wired-AND connections, enabling the creation of multi-comparator configurations.

The LM339QT features a low input bias current, typically 25 nA, and a low input offset current, typically 5 nA, which ensures minimal impact on the circuits being monitored. The input common-mode voltage range includes ground, even when operating from a single power supply, making the device particularly useful for ground-referenced sensors.

With its low supply current drain, independent of the supply voltage, typically 0.8 mA, the LM339QT is an excellent choice for battery-powered devices, offering an optimal balance between power consumption and performance. Its ability to operate over a wide temperature range, from -40°C to +105°C, makes it suitable for industrial, automotive, and consumer applications that demand reliability under varying environmental conditions.

The device is offered in a 14-pin TSSOP package, which ensures a compact footprint on printed circuit boards. The LM339QT is part of a family of products that provide a variety of comparator options, including different package types and specifications, allowing designers to select the most appropriate comparator for their specific application needs.

Overall, the LM339QT quad comparator is a versatile and reliable component that enhances the efficiency and performance of electronic systems, solidifying its role as a staple in the electronics industry.