LM339DR Datasheet

LM139-N , LM239-N , LM2901-N , LM3302-N , LM339-N
SNOSBJ3E –NOVEMBER 1999–REVISED DECEMBER 2014 www.ti.com
8 Application and Implementation
NOTE
Information in the following applications sections is not part of the TI component
specification, and TI does not warrant its accuracy or completeness. TI’s customers are
responsible for determining suitability of components for their purposes. Customers should
validate and test their design implementation to confirm system functionality.
8.1 Application Information
The LM139-N is specified for operation from 2.0 V to 36 V (±1V to ± 18V) over the temperature range of –55°C to
125°C. While it may seem like a comparator has a well-defined and somewhat limited functionality as a '1-bit
ADC', a comparator is a versatile component which can be used for many functions.
Refer to AN-74 LM139/LM239/LM339 A Quad of Independently Functioning Comparators (SNOA654) for
additional application information on use of the LM139-N.
8.2 Typical Applications
8.2.1 Basic Comparator
Figure 11. Basic Comparator Schematic
8.2.1.1 Design Requirements
The basic usage of a comparator is to indicate when a specific analog signal has exceeded some predefined
threshold. In this application, the negative input is tied to a reference voltage, and the positive input is connected
to the input signal. The output is pulled up with a resistor to the logic supply voltage, V+.
For an example application, the supply voltage is 5 V. The input signal varies between 1 V and 3 V, and we want
to know when the input exceeds 2.5 V. For this example, we would set the V
REF
to 2.5 V.
8.2.1.2 Application Curve
Figure 12. Basic Comparator Response
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Product Folder Links: LM139-N LM239-N LM2901-N LM3302-N LM339-N