8.1 Overview

The TPS543B20 device is 25-A, high-performance, synchronous buck converter with two integrated N-channel NexFET™ power MOSFETs. These devices implement the fixed frequency non-compensation mode control. Safe pre-bias capability eliminates concerns about damaging sensitive loads. Two TPS543B20 devices can be paralleled together to provide up to 50-A load. Current sensing for over-current protection and current sharing between devices is done by sampling a small portion of the power stage current providing accurate information independent on the device temperature.

Advanced Current Mode (ACM) is an emulated peak current control topology. It supports stable static and transient operation without complex external compensation design. This control architecture includes an internal ramp generation network that emulates inductor current information, enabling the use of low ESR output capacitors such as multi-layered ceramic capacitors (MLCC). The internal ramp also creates a high signal to noise ratio for good noise immunity. The TPS543B20 has 10 ramp options (see Ramp Selections for detail) to optimize internal loop for various inductor and output capacitor combinations with only a simple resistor to GND. The TPS543B20 is easy to use and allows low external component count with fast load transient response. Fixed-frequency modulation also provides ease-of-filter design to overcome EMI noise.