In this article we all learn about comparator IC, it’s key parameter, applications and comments. So let’s first start with what is comparator IC or it’s description
Description of Compartor IC
Essentially a very fast-acting high-gain differential amplifier, a comparator senses the difference between two voltages and, by rapid amplification, provides maximum output immediately. De-signed for low-input current, most comparators are essentially voltage devices that interface with digital logic circuits. The various types of comparators differ primarily in the emphasis of some key parameters, such as low power consumption, fast operating time, high input impedance, and stability over a range of temperatures.
Key Parameters of Comparator IC
- Response time; The length of time required from the appearance of a voltage in excess of the comparator threshold to the time that the output has reached its maximum, the logic level. 50 to 500 ns is typical.
- Off-set voltage: The difference between the two input terminals. Typical values from 0.5 to 10 mV.
- Offset current: The input current difference between the two-input terminal. Typical values range from 10 to 100 nA.
- Voltage gain: the difference between input and output, stated either in overall ratio or in volts output versus millivolts input. Typical voltage gain are 200 to 500,000.
- Output voltage level: For compatibility with difference types of logic families, specific logic levels to indicate a “zero” and “one” are given.
- Output current: The soured or sink current for compatibility with specific digital logic families.
- Power supply: Many comparators requires positive and negative power supply voltages, but these are some on the market that operate from a single voltage and are therefore more easily compatible with the logic families they are supposed to interface with.
Applications
Comparators can be used as threshold detectors, zero-crossing detectors, level changers for different logic levels, detectors for magnetic transducer, window detectors, high stability oscillators, and various analog interface circuits for digital logic systems.
Representative Part Number: Precision Monolithic LM339,
Comments
Most voltage comparators are available in two or four per DIP IC. In some instance medium-power transistor-driven amplifiers are included in the IC to allow the output of the voltage comparator to drive a number of different logic elements.