L78S09CV-DG

L78S09CV-DG Application Field and Working Principle

The L78S09CV-DG voltage regulator is a member of STMicroelectronics\' low dropout (LDO) voltage regulator family. It is a positive voltage regulator integrated circuit, which features a very low dropout voltage of only 0.8V, making it particularly suitable for applications that require low power consumption and low heat dissipation. It is most commonly used for providing a regulated output voltage to microcontrollers, FPGA, and ASIC designs.

The L78S09CV-DG voltage regulator has a wide input voltage range, with an absolute maximum rating of 40V, and can provide an output voltage range of 3V to 20V. It has a 500mA maximum output current, and can withstand a maximum surge current of 1A. The device is protected against overcurrent and overvoltage, and also has a current limit and thermal shutdown feature, providing protection to the circuit in case of overload or over-temperature.

The working principle of the L78S09CV-DG voltage regulator is based on the fact that the output voltage remains stable, even in the presence of variations in the input voltage. This is achieved by the use of a voltage reference, which compares the input and the output voltage, and adjusts the output voltage accordingly. The output voltage is regulated by the controlling the amount of current drawn from the input, which is achieved by adjusting the amount of current through the transistor (pass transistor), with the help of a feedback loop.

The L78S09CV-DG voltage regulator is available in a wide variety of packages, including TO-220, TO-220F, TO-263 and SOT-223. Furthermore, the device has an excellent temperature stability, and an adjustable output voltage, making it ideal for many different applications.