Building a Better –48 VDC Power Supply for 5G and Next-Generation Telecom Equipment

Demand for mobile data is growing at a steep rate as new markets and applications continue to emerge. There are no other solutions than to deploy additional cellular sites in greater density. These factors will directly affect the design of macrocell, small cell, and femtocells products. The radios are now multiband, and power amplifier (PA) design engineers are pushing the PAs’ output power to higher limits/levels. This article focuses on 80 W PAs with several PAs in the system. It has become commonplace to see 1400 W remote radio unit (RRU) platforms.However, network operators want these RRUs to be more power efficient,more reliable, and more compact as they increase coverage density. The point of loads (PoL) need to work over wide input voltages and wide operating temperature ranges, and most importantly they must be cost-effective. However,for applications needing 500 W or more power, the magnetics design and conduction losses in the secondary circuitry of an active clamp forward converter design have become difficult to manage because of the need for an advanced control scheme to keep the delay timing between the active clamp and the main switch gate drive. This article presents a scalable and stackable –48 VDC PoL solution that will address the high density power usage situations created by these high density networks from the tremendous growth in network traffic.