Modem ASIC Design with minimal power consumption for the IDU of a SATCOM terminal: RTL to GDS II

The design & development of a Modem ASIC with reduced power consumption; forming a key part of the Indoor Unit (IDU) of a SATCOM terminal is presented in this paper. The inspiration behind developing a Low Power Modem ASIC is to reduce weight, volume, power, manufacturing effort and cost of the SATCOM Terminals intended for mobile applications. The ASIC is provided with programming interfaces (SPI & UART) to allow requisite registers to be loaded for enabling a specific application post-production. The reported modem ASIC can support various modulation schemes, FEC and data rates ranging from 2400bps to 40 Mbps; thus enabling a variety of multimedia applications. The paper also details the various types of power consumed in an ASIC along with the approaches to reduce them. Through an optimum mix of these mitigation techniques, chiefly memory gating; more than 50% reduction in power consumption / dissipation is achieved in the reported memory-intensive ASIC design. The final ASIC comprising nearly 2.7M logic gates is accommodated into a highly compact die size of 169mm
²
using 180 nm CMOS technology. Actual test results on realized prototypes show validation of all functional requirements and only 1.9 watts (@100 MHz System clock) of power consumption which is further reduced when compared to 3.65 watts obtained by power analysis tool (which considers certain margins.)