Multi-Phase DC Power Supply Topologies with Fast Response for Telecom and Point-of-Load Applications

The evolution of the 4G/5G communication networks along with high-speed computing and datacenter facilities increased the demand for compact, efficient, and reliable power supplies with faster output response speeds. The advancements in high-speed semiconductor switching devices and magnetics have constantly raised the scope for the design of efficient, compact power supplies with a faster dynamic response. These opportunities and requirements are contributed to undertake the research proposed in this work. In high-speed radio frequency (RF) communication applications, when supplied with a constant power source the radio frequency power amplifier (RFPA) dissipates energy in the form of heat. This power loss increases proportionately with the speed of the communication system. This needs more cooling and makes the overall system bulky. In this work, efficient power supply topologies with fast varying output voltage are proposed to modulate the drain power supply of an RFPA and reduce the loss dissipation. Multilevel converters are explored as a suitable option for this application and high-frequency gate drive circuits are proposed. A cascaded switching capacitor-based three-level multi-phase converter is proposed to eliminate complex switching capacitor voltage control circuitry. A modified PWM technique is introduced to maintain a linear relationship of output to the input voltage. Zero voltage switching (ZVS) output filter design is proposed to reduce turn-on switching loss and maintain current self-balancing in the multi-phase converter. Point-of-load (POL) regulators are used in the DC power distribution of data centers to convert high DC bus input voltage (12 V – 48 V) to the low POL output voltage (1.2 V – 6 V). The load current demand fluctuates rapidly over a wide range, and if it’s not properly taken care of, the output voltage fluctuates and may damage the sensitive load equipment. In addition, data centers consume a large amount of power which leads to the development of high-efficiency power converters to remain cost-effective. In this work, a single-stage efficient POL converter is proposed to address the high-speed load current transients and regulate the output voltage. A variable switching frequency scheme is proposed to improve the light load efficiency and current self-balancing is used to improve the power-sharing in the multi-phase converter.