LX1554CPW

The LX1554CPW is a high performance current-mode offline switcher that encompasses the discrete switching components, resonant timing and Analog-to-Digital (A/D) conversion functions into a single-chip architecture. The integrated nature of the IC simplifies design complexity and facilitates a complete solution with a small board size and low overall system cost. The LX1554CPW is intended for use in a variety of applications, including lighting, fans and pumps, and industrial control of motors, pumps, and solenoids.

The LX1554CPW implements a simple current-mode control (CCM/DCM) in a single chip topology. This configuration is most widely used for offline switchers due to its low component count, high efficiency, and relatively noiseless operation. The LX1554CPW can be operated from an input voltage range of 7V to 48V and can output up to 12V at up to 6A, with a minimum start-up current of 150mA. The IC features an array of integrated functions to easily customize the application, such as a latch circuit, self-protection, and soft start.

The LX1554CPW utilizes a continuous conduction mode (CCM) for power conversion. This mode is generally used in voltage-mode systems, but due to its high efficiency and low component count it is also ideal for current-mode applications. The LX1554CPW operates in a CCM-like mode due to its hysteretic control architecture, where it is able to maintain continuous conduction of the top switch in the power stage. The design also allows for operation in discontinuous conduction mode (DCM) under light loads where operation in DCM can improve efficiency and lower the total system cost by eliminating the need for additional components.

The LX1554CPW includes an integrated VSS (Voltage Sense Synthesizer) that senses input voltage, and automatically adjusts its operating frequency to limit switching losses. This function also automatically adjusts for different input voltages and allows the system to optimize for the given load. Additionally, the LX1554CPW features an optional overcurrent protection module which senses for a possible overcurrent condition and shutdowns the device if the load current exceed the set limit.

The LX1554CPW also features an integrated oscillator, which provides a range of frequency modulation options. The oscillator features both a frequency- modulation range as well as an adjustable frequency range to provide the system with an optimal switching frequency to minimize switching losses. The frequency range can be programmed through digital control pins or an external resistor.

The LX1554CPW is an ideal solution for high efficiency, low cost offline switchers applications. It is easy to design with, requires minimal component count, and is ideal for a wide range of applications ranging from lighting, fans and pumps, and industrial control of motors and pumps. The LX1554CPW has been designed to provide high performance, as well as a high degree of flexibility and customization to satisfy a variety of application needs.