The HT7521-3 is a Low Dropout Regulator (LDO) for voltage regulation in variable power supply, providing excellent line and load regulation and very low dropout voltage to 12V. This device is SOT-89 RoHS compliant and is manufactured by Holtek. It has a high quiescent current, good ripple rejection ratio, low ground pin current, fast turn-on time and good load/line transient response. It achieves a very high efficiency, and its low dropout voltage reduces power dissipation and hence improves overall system efficiency. The device also offers LDO protections, including over-current limiting, over-temperature protection and short-circuit protection. Additionally, its low power consumption and high quiescent current make it suitable for battery-operated systems. It is suitable for use in applications with high power density, and it supports a wide range of input voltage, from 2.5V to 24V.