Optimization-based framework for simultaneous circuit-and-system design-space exploration: a high-speed link example

Connecting system-level performance models with circuit information has been a long-standing problem in analog/mixed-signal front-ends, like radios and high-speed links. High-speed links are particularly hard to analyze because of the complex interplay of device/circuit parasitics and channel filtering operation. In this paper we introduce optimization-based framework for link design-space exploration, connecting the link transmission quality and top-level filter settings with circuit power, sizing and biasing. We derive a special analytical discrete time representation that avoids the size explosion of the symbolic problem description improving the parsing and solver time by orders of magnitude and making this joint optimization possible in real-time. This robust and accurate problem formulation is derived in signomial form and is compatible with existing optimization approaches to circuit sizing. We demonstrate this optimization framework on a link design-space exploration example, investigating trade-offs between the transmit preemphasis and linear receiver equalizer and their impact on overall link power vs. data rate.