LM2599T-12/NOPB

LM2599T-12/NOPB Application Field and Working Principle

LM2599T-12/NOPB is a DC-DC step-down converter developed by Texas Instruments. It belongs to a type of switch mode voltage regulator called an integrated synchronous rectifier (SR) regulator. It is designed to provide a regulated output voltage of 12V and operates at a switching frequency of 400kHz. The LM2599T-12/NOPB is capable of delivering an output current of up to 1.5A.

The LM2599T-12/NOPB is used primarily in applications such as servers, telecom and network equipment, DC-DC converters, power supplies and mobile power supply systems. In these applications it is able to produce a clean and stable output voltage from an unregulated input voltage range of up to 40V. The LM2599T-12/NOPB is also highly efficient, achieving up to 97% efficiency for certain input voltages.

Design and Features

The LM2599T-12/NOPB is a 4-pin device and includes a power switch, an inductor, Schottky diodes, an input filter capacitor and a resistor for current limit protection. Its integrated synchronous rectifier regulator design incorporates an integrated MOSFET switch to prevent the output voltage from going beyond the set limit. The LM2599T-12/NOPB also features a Cycle-by-Cycle Current Limit protection function that ensures system protection, and a thermal shutdown that protects it from excessive heat. Additionally, the device has an EN and FB input pin which enable setting of the output voltage and enable/shutdown functions.

Working Principle

The LM2599T-12/NOPB is based on a switched-capacitor converter topology. It generates an output voltage by charging a capacitor between two output terminals. The amount of charge stored in the capacitor determines the output voltage. The output voltage is regulated by modulating the duty cycle of the power switch during each charging cycle. The power switch is typically a MOSFET, which is driven by an oscillator block, the duty cycle of which is used to control the output voltage.

The oscillator signal is applied to the power switch and creates a voltage drop across the switch terminal. This voltage drop creates a magnetic field in the inductor which stores energy. The inductor then releases this energy to the output voltage terminal. This helps maintain the output voltage at a constant level determined by the duty cycle of the power switch. The oscillator also operates at a high frequency, typically 400kHz, to allow for a compact design.

Benefits

The LM2599T-12/NOPB is a highly integrated and efficient switch mode voltage regulator. It offers a cost effective solution for a wide range of applications. Its high efficiency and small size make it ideal for a variety of mobile and industrial applications. The device is also protected from thermal overstress, over-current and short-circuit, ensuring reliable operation in all conditions. Additionally, the device provides good noise immunity and low output ripple making it suitable for audio, video and telecommunication applications.