A Unified Clock and Switched-Capacitor-Based Power Delivery Architecture for Variation Tolerance in Low-Voltage SoC Domains
| Autor: | Naveen John, Rajesh Pamula, Fahim ur Rahman, Sung Kim, Roshan Kumar, Xi Li, Keith Bowman, Visvesh S. Sathe |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Physics
020208 electrical & electronic engineering Clock rate Hardware_PERFORMANCEANDRELIABILITY 02 engineering and technology Topology Switched capacitor Capacitance Phase-locked loop CMOS Hardware_INTEGRATEDCIRCUITS 0202 electrical engineering electronic engineering information engineering Voltage droop Electrical and Electronic Engineering Low voltage Voltage |
| Zdroj: | IEEE Journal of Solid-State Circuits. 54:1173-1184 |
| ISSN: | 1558-173X 0018-9200 |
| DOI: | 10.1109/jssc.2018.2888866 |
| Popis: | Correctly operating digital SoC domains at their target frequencies require the addition of supply voltage ( $V_{\mathrm{ dd}}$ ) guardbands to account for supply droop events and temperature variation. These guardbands degrade processor energy efficiency, especially in low-voltage sensor and IoT applications due to increased delay sensitivity to temperature and $V_{\mathrm{ dd}}$ variation. In this paper, we present an all-digital unified clock and power (UniCaP-SC) architecture that combines switched-capacitor (SC)-based voltage control and clock frequency regulation into a single loop to significantly reduce required $V_{\mathrm{ dd}}$ guardbands. A UniCaP-SC test chip consisting of a near-threshold voltage (NTV) ARM Cortex-M0 processor was fabricated in 65-nm CMOS. The fully integrated system enables all-digital construction, aggressive $V_{\mathrm{ dd}}$ margin reduction, and continuous $V_{\mathrm{ dd}}$ scalability using SC-based voltage converters while no additional decoupling capacitance (decap). Test-chip measurements demonstrate a 16% $V_{\mathrm{ dd}}$ reduction corresponding to a 94% $V_{\mathrm{ dd}}$ margin recovery or an equivalent $3.2\times $ increase in the operating clock frequency ( $f_{\mathrm{ clk}}$ ). |
| Databáze: | OpenAIRE |
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