0.45 v and 18 μA/MHz MCU SOC with Advanced Adaptive Dynamic Voltage Control (ADVC)

Abstract

An ultra-low-power MicroController Unit System-on-Chip (MCU SOC) is described with integrated DC to DC power management and Adaptive Dynamic Voltage Control (ADVC) mechanism. The SOC, designed and fabricated in a 40 nm ULP standard CMOS technology, includes the complete Synopsys ARC EM5D core MCU, featuring a full set of DSP instructions and minimizing energy consumption at a wide range of frequencies: 312 K-80 MHz. A number of unique low voltage digital libraries, comprising of approximately 300 logic cells and sequential elements, were used for the MCU SOC design. On-die silicon sensors were utilized to continuously change the operating voltage to optimize power/performance for a given frequency and environmental conditions, and also to resolve yield and life time problems, while operating at low voltages. A First Fail (FFail) mechanism, which can be digitally and linearly controlled with up to 8 bits, detects the failing SOC voltage at a given frequency. The core operates between 0.45-1.1 V volts with a direct battery connection for an input voltage of 1.6-3.6 V. Measurement results show that the peak energy efficiency is 18µW/MHz. A comparison to state-of-the-art commercial SOCs is presented, showing a 3-5× improved current/DMIPS (Dhrystone Million Instructions per second) compared to the next best chip.

A Nano-Power 0.5 V Event-Driven Digital-LDO with Fast Start-Up Burst Oscillator for SoC-IoT

“…A key component of such SoC-IoT applications is the Low Drop-Out regulator (LDO). LDOs are DC voltage regulators that regulate the output voltage even when it is close to supply output voltage, which is the case in sub-1 V general IoT [2,3] and passive radio communication systems. In such a system as seen in Figure 1, the power efficiency is maximized with the minimization of the drop-out voltage which is defined as the difference from the rectified voltage to the power line voltage.…”

0.45v and 18pA/MHz MCU SOC with advanced Adaptive Dynamic Voltage Control (ADVC)

“…Several publications presented state-of-the-art IC solutions with integrated dynamic voltage and frequency scaling (DVFS) [19][20][21], allowing adaptation of the voltage to the frequency requirements. The design of complex (and cost This paper is an extended version of [29], where we briefly presented the proposed MCU SOC for the first time. In this paper, we extend the content by adding detailed descriptions of the concepts of library characterization, first fail circuit operation, DC2DC and ADC circuits and providing schemes of the circuits, used in the PMU.…”

“…The low voltage associated with frequency reduction is not suitable for all modes of operation, and an adaptive voltage control mechanism is required. Lower supply voltages also mean lower noise margins, reduced yield, and increased vulnerability to process variations and temperature fluctuations [27][28][29][30][31][32]. The characteristics of semiconductor behavior in sub/near-threshold are not well represented by standard transistor models and are different from those in the super-threshold region, resulting in different sizing and ratio optimizations.The subthreshold current is exponentially dependent on the transistor's threshold voltage.…”

“…Therefore, specific measures need to be taken to deal with this drawback.Sub-threshold and near-threshold circuits have received a lot of attention in the research community during the last decade [6-8,10-13] with successful ultra-low voltage chip implementations: microprocessors [6,8,[10][11][12], as well as dedicated ASICs for biomedical applications [7,13,[33][34][35][36], for wireless sensor nodes [10,15,17,[37][38][39], communication [40,41], image processing [42,43], RFIDs [44] and many others. While previous research indicated significant power reduction and successful minimum energy operation, it did not present complete MCU SoC solutions that are suitable for mass production.This paper presents a 40 nm MCU System-on-a-Chip (SoC), which includes the complete Synopsys ARC EM5D core MCU and features a full set of DSP instructions [29]. The SoC demonstrates minimum energy per operation and reliably adapts its operation to different environmental conditions across a wide operating voltage range (0.45 V to 1.1 V).…”

“…This paper presents a 40 nm MCU System-on-a-Chip (SoC), which includes the complete Synopsys ARC EM5D core MCU and features a full set of DSP instructions [29]. The SoC demonstrates minimum energy per operation and reliably adapts its operation to different environmental conditions across a wide operating voltage range (0.45 V to 1.1 V).…”