LT1129CQ#PBF

Linear voltage regulators offer improved accuracy, stability, and efficiency compared to the more traditional switching regulators. The LT1129CQ#PBF Linear Voltage Regulator is a very popular device in this segment, and its application field and working principle are explained in detail in this article.

Description

The LT1129CQ#PBF is a high-performance, low-cost, single-supply, low-dropout linear voltage regulator. It is an adjustable version of the LTC1022 and provides lower output voltages with higher accuracies than other linear regulators. The LT1129CQ#PBF features a very low 0.3V dropout, high output accuracy, and low quiescent current of 1μA. It also features a low-saturation output current of 10mA, with an adjustable output voltage from +1.25V to +15V.

Features

• Low quiescent current of only 1μA
• Input voltage range from 2.7V to 33V
• Output voltage adjustable from 1.25V to 15V
• Maximum output current of 10mA
• Excellent line and load regulation
• Piece-by-piece 100% testing

Applications

• Battery powered applications
• Charge pumps
• Power distribution networks
• On-board voltage regulation
• Over-voltage protection
• Audio amplifiers

Working Principle

The LT1129CQ#PBF works by controlling the amount of current flowing from the input to the output by means of a transistor. The transistor functions as a variable resistor, depending on the voltage at the input and the voltage on the output. When the input voltage is higher than the output voltage, the transistor increases its resistance, regulating the amount of current going from the input to the output. Conversely, when the input voltage is lower than the output voltage, the transistor decreases its resistance, allowing more current to flow from the input to the output. The resulting current allows the output voltage to remain at a constant level.

Conclusion

The LT1129CQ#PBF Linear Voltage Regulator is a highly versatile device, offering excellent accuracy and stability combined with low quiescent current and wide input and output voltage ranges. It is ideal for applications such as battery powered devices, charge pumps, and audio amplifiers, and can also be used for power distribution networks and on-board voltage regulation.