LM5116WG/NOPB

Abstract This article will discuss the LM5116WG/NOPB Application Field and Working Principle. It will cover the details of application areas, working principle, use and structure. This is a DC/DC Switching Controller with integrated power devices to produce control loops. It is ideal for isolated and non-isolated applications where high-efficiency, high-power density, and low-cost are needed.

IntroductionThe LM5116WG/NOPB is a state-of-the-art DC/DC switching controller specifically designed for applications where high-efficiency, high-power density, and low-cost are paramount. The controller is available in a 20-pin wide body SOIC package and is ideal for both isolated and non-isolated solutions operating up to 600 kHz. The LM5116WG/NOPB uses a fixed frequency voltage mode (VM) control scheme and a configurable valley current limit to achieve efficient and cost-effective control over a wide load and output voltage range. Additionally, the integrated low-side power device reduces board space and total solution cost by eliminating the need for an external power MOSFET.

Application FieldThe LM5116WG/NOPB is an ideal alternative to linear voltage regulators by providing improved efficiency, reducing power dissipation and overall solution cost. Typical applications include DC/DC converters with medium to high power requirements such as redundant power systems, telecom supplies, server power supplies, and distributed power architectures. It can be used with both isolated and non-isolated topologies with output voltages from 12 to 38 VDC and output power levels up to 60 W. The LM5116WG/NOPB can generate output voltages from as low as 0.7V to as high as 40V. It is equally suitable for applications needing wide range adjustment from as low as 0.2V to as high as 38V. The integrated gate driver enables the controller to provide up to 600 kHz of frequency response and can accurately control both current mode and voltage mode conditions.

Working PrincipleThe LM5116WG/NOPB uses a fixed-frequency, voltage-mode control scheme to achieve high-efficiency operation over load and line conditions. It consists of a high-speed comparator, an oscillator, a valley current limit circuit and a gate driver. Upon application of an input voltage, the comparator senses the voltage drop across a resistor, R1 in the feedback circuit. The output of the comparator is applied to the oscillator, which in turn drives the valley current limit circuit and the gate driver. The resulting output voltage is monitored by a feedback network, R2 and C1, for load conditions and compared to the voltage setpoint for line conditions.

The valley current limit circuit provides a constant peak current limiting function. This prevents over-current conditions which could damage the power supply switching elements. The gate driver provides the output voltage level control signals to the external PWM switches, thus regulating the output voltage. The LM5116WG/NOPB also provides programmable soft-start and over-voltage protection.

Use and Structure The LM5116WG/NOPB offers a wide range of features such as: voltage mode control, adjustable frequency operation, constant peak current limiting, integrated gate driver, adjustable PFM mode, adjustable soft-start and over-voltage protection. The integrated low-side power device reduces board space and total solution cost by eliminating the need for an external power MOSFET. The integrated DMOS power device is ideally suited for high-frequency applications and can provide up to +100A current drive capability for a wide range of voltage combinations.The LM5116WG/NOPB is available in a 20-pin wide body SOIC package and can operate from a wide input voltage range from 4.5V to 60V and supports output voltages up to 40V. The LM5116WG/NOPB is optimized for high-efficiency operation and provides programmable frequency up to 600 kHz. Additionally, the controller is also available with an integrated buck transformer driver (LM5116WG/NOPBTR) to provide reduced voltage ripple as well as improved system efficiency.

ConclusionThe LM5116WG/NOPB is a state-of-the-art DC/DC switching controller specifically designed for applications where high-efficiency, high-power density, and low-cost are paramount. It offers a wide range of features such as voltage mode control, adjustable frequency operation, constant peak current limiting, integrated gate driver, adjustable PFM mode, adjustable soft-start and over-voltage protection. The controller is available in a 20-pin wide body SOIC package and is ideal for both isolated and non-isolated solutions operating up to 600 kHz.