A 28nm High-κ metal-gate single-chip communications processor with 1.5GHz dual-core application processor and LTE/HSPA+-capable baseband processor

The increase in the use and number of smartphone devices is causing heavy data traffic volumes on existing 3G mobile wireless networks. LTE, often referred to as 4G, offers true mobile broadband. It is a new network and access technology that provides new spectrum resources, much increased spectral efficiency, higher throughputs (150Mb/s with higher rates to come), at lower latency and it uses an IP-based infrastructure. LTE is the solution to mitigate the traffic load issue and it is being rolled out around the world. The proposed communication processor R-Mobile U2 (RMU2) achieves single-chip integration of a 1.5GHz dual-core application processor and a triple mode (GSM/WCDMA/LTE) base-band processor. Key design highlights of the RMU2 are: 1) A 28nm HKMG high-performance and low-leakage (HPL) CMOS bulk process achieves an optimal balance between both low leakage current and high performance. 2) A CPU clock control mechanism, called the “power saver”, limits the CPU power so as not to exceed a threshold level and to reduce IR drop. 3) The internal power domain is separated into 33 sub-blocks with I/O NMOS power switches [1] to minimize leakage current of any unused sub-block. 4) A dual-mode low-leakage SRAM [2] achieves low standby current in addition to conventional memory characteristics.