UCC2975PW

UCC2975PW Application Field and Working Principle

UCC2975PW, a product of Texas Instruments, is a highly integrated and fully featured 3-phase bridge controller optimized for driving 3-phase power MOSFETs. The main function of this controller is to provide protection and control of high-power 3-phase AC-DC power converters such as buck converters, flyback converters, and boost converters. It provides full protection against malfunction, including output undervoltage, overvoltage, overcurrent, and short circuit protection, while at the same time minimizing the external component count.

Application Field

The UCC2975PW is perfectly suited for applications such as large industrial power supplies, telecom power systems, portable and small form factor PoE (power-over-ethernet) systems, the GL850G board, and consumer power supplies such as external AC adapters, laptop power supplies and LED lighting. It is also useful for renewable energy such as solar and wind power.

Working Principle

The UCC2975PW provides run, ramp, overcurrent, insulation protection, short circuit protection, shoot-through protection and current-sense signal conditioning. The controller\'s digital core is controlled by an internal 20-bit resolution timer and includes a unique set of control functions that can be individually configured. The timer controls the switching waveform of the power MOSFETs and the associated drive signals, and can be used to vary the on-time and off-time of the converter to suit the output power requirements. To ensure a smooth transition between the run and ramp states, the chip includes dead time control, burst mode, and adjustable slew rate compensation.

The chip also features a highly stable programmable current limit for the load, allowing for a wide range of load currents. The current-sensing circuit of the UCC2975PW is constructed from an internal current-sense amplifier and a differential comparator, providing a high level of accuracy and reliability. The sensing voltage is internally scaled to be proportional to the output current of the power MOSFETs to ensure the power supply is operated within its safe operational limits.