An embedded energy monitoring circuit for a 128kbit SRAM with body-biased sense-amplifiers

Embedded energy monitoring of critical system components can be used to enable better power management by capturing run time system conditions such as temperature and application load. In this work, an energy sensing circuit that provides digitally represented absolute energy per operation of a 128kbit SRAM is presented. Designed in a 65nm low-power CMOS process, SRAMs can operate down to 370 mV. Energy sensing circuit consumes 16.7μW during sensing at 1.2V (only 0.28% of SRAM active power at the same voltage). For improved performance, SRAMs utilize body-biased PMOS input strong-arm type sense amplifiers that can achieve 45% tighter input offset distribution for only ~3.5% of total SRAM area overhead.

[1]  Anantha P. Chandrakasan,et al.  A 45nm 0.5V 8T column-interleaved SRAM with on-chip reference selection loop for sense-amplifier , 2009, 2009 IEEE Asian Solid-State Circuits Conference.

[2]  W. Dehaene,et al.  A 3.6pJ/access 480MHz, 128Kbit on-Chip SRAM with 850MHz boost mode in 90nm CMOS with tunable sense amplifiers to cope with variability , 2008, ESSCIRC 2008 - 34th European Solid-State Circuits Conference.

[3]  Nathan Ickes,et al.  A 10 pJ/cycle ultra-low-voltage 32-bit microprocessor system-on-chip , 2011, 2011 Proceedings of the ESSCIRC (ESSCIRC).

[4]  William J. Bowhill,et al.  A 32nm 3.1 billion transistor 12-wide-issue Itanium® processor for mission-critical servers , 2011, 2011 IEEE International Solid-State Circuits Conference.

[5]  George Kurian,et al.  Self-aware computing in the Angstrom processor , 2012, DAC Design Automation Conference 2012.

[6]  A.P. Chandrakasan,et al.  Minimum Energy Tracking Loop With Embedded DC–DC Converter Enabling Ultra-Low-Voltage Operation Down to 250 mV in 65 nm CMOS , 2008, IEEE Journal of Solid-State Circuits.

[7]  A.P. Chandrakasan,et al.  A 256 kb 65 nm 8T Subthreshold SRAM Employing Sense-Amplifier Redundancy , 2008, IEEE Journal of Solid-State Circuits.

[8]  Joseph A. Paradiso,et al.  Energy Metering for Free: Augmenting Switching Regulators for Real-Time Monitoring , 2008, 2008 International Conference on Information Processing in Sensor Networks (ipsn 2008).