LM1117IMPX-5.0

LM1117IMPX-5.0 application field and working principle

LM1117IMPX-5.0 is a low-dropout linear regulator from Texas Instruments, classified in the PMIC group of Voltage Regulators - Linear. It is designed for battery-powered systems which require constant supply current or for supplying very low quiescent current applications. The regulator has a voltage range of from 2.25V to 13.2V, as well as offering very low dropout and output noise. The maximum output current is 1A with a minimum dropout voltage of 0.4V at full load.

Features

The LM1117IMPX-5.0 offers several features including:

• Low Dropout Voltage: the minimum dropout voltage of 0.4V allows for optimal load regulation even when applied with a low load regulation requirement.
• Low Output Noise: The regulator features 0.1% RMS noise performance that is more than sufficient to meet the load regulation requirement along with providing a comfortable noise margin.
• Programmable Output Voltage: The device is programmable to provide a constant output voltage with a margin of error of only 0.1%.
• Wide Range of Output Voltages: The device is designed to be used with a wide range of output voltages from 2.25V to 13.2V in both 1.0V and 0.5V increments.

Applications

As a low-dropout linear regulator, the LM1117IMPX-5.0 is suitable for applications, such as:

• Battery-powered technologies: since the maximum dropout voltage is only 0.4V, it allows for a significant increase in battery life.
• Low-noise and high accuracy power supplies: due to its low output noise and high accuracy, this device can be used in applications, such as digital televisions, audio systems, and radio transmitters.
• Power management in automotive applications: in order to ensure optimal performance, the device can be used for regulating the power levels in automotive applications.

Working Principle

The LM1117IMPX-5.0 regulator works on the same principle as any other linear regulator. The device has two operational states - one that regulates the output voltage and one that controls the output current. The voltage regulator is formed by two MOSFETs connected to a voltage comparator inside the device. The MOSFETs are like two switches, with their gates then connected to the voltage comparator. The voltage comparator compares the output voltage to the input voltage and when the output voltage is higher than the input voltage, the MOSFETs turn off and the regulation of the output voltage stops. The device then goes into a current regulation state where the output current is regulated. The regulator adjusts the current being delivered to the load by controlling the voltage across the output current sensing resistor, R2. When the voltage across R2 is increased, the output current is increased, as the voltage is also increased. Similarly, if the voltage across R2 is decreased, the output current is decreased, as the voltage is also decreased.

The LM1117IMPX-5.0 offers low dropout voltage, low output noise, and a wide range of output voltages. This makes it an ideal choice for applications that require constant supply current or for supplying low quiescent current applications, such as battery-powered technologies and power management in automotive. The device is easy to setup and use, making it a reliable regulator for many applications.