PMC:4313588 / 2252-3453
Annnotations
{"target":"http://pubannotation.org/docs/sourcedb/PMC/sourceid/4313588","sourcedb":"PMC","sourceid":"4313588","source_url":"https://www.ncbi.nlm.nih.gov/pmc/4313588","text":"Most analog neuromorphic implementations of plasticity rely on subthreshold circuits (Indiveri et al., 2006) to achieve the small currents necessary for these long time constants. However, these are hard to port to advanced CMOS techologies, since leakage currents rapidly increase with down-scaling, reaching the range of the desired signal currents (Roy et al., 2003). Some plasticity circuits have also been implemented in OTA-C architectures (Koickal et al., 2007; Noack et al., 2011), but these suffer from the same problems with small currents. Digital plasticity circuits (Cassidy et al., 2011) are not subject to this limitation, but have limited biological veracity due to their digital state variables. For subthreshold circuits, an additional problem is the increase of device mismatch and process variation (Kinget, 2005), making transistors almost unusable for the exponential computation that subthreshold circuits rely upon. This is why even recent subthreshold neuromorphic systems have been manufactured in quite large technologies (Bartolozzi and Indiveri, 2007; Indiveri et al., 2010; Moradi and Indiveri, 2013), with the sole exception a recent design in 90 nm (Park et al., 2014).","tracks":[{"project":"0_colil","denotations":[{"id":"25698914-16526488-299593","span":{"begin":103,"end":107},"obj":"16526488"},{"id":"25698914-24732237-299594","span":{"begin":828,"end":832},"obj":"24732237"},{"id":"25698914-17716003-299595","span":{"begin":1075,"end":1079},"obj":"17716003"},{"id":"25698914-24681923-299596","span":{"begin":1125,"end":1129},"obj":"24681923"}],"attributes":[{"subj":"25698914-16526488-299593","pred":"source","obj":"0_colil"},{"subj":"25698914-24732237-299594","pred":"source","obj":"0_colil"},{"subj":"25698914-17716003-299595","pred":"source","obj":"0_colil"},{"subj":"25698914-24681923-299596","pred":"source","obj":"0_colil"}]},{"project":"2_test","denotations":[{"id":"25698914-16526488-38235645","span":{"begin":103,"end":107},"obj":"16526488"},{"id":"25698914-24732237-38235646","span":{"begin":828,"end":832},"obj":"24732237"},{"id":"25698914-17716003-38235647","span":{"begin":1075,"end":1079},"obj":"17716003"},{"id":"25698914-24681923-38235648","span":{"begin":1125,"end":1129},"obj":"24681923"}],"attributes":[{"subj":"25698914-16526488-38235645","pred":"source","obj":"2_test"},{"subj":"25698914-24732237-38235646","pred":"source","obj":"2_test"},{"subj":"25698914-17716003-38235647","pred":"source","obj":"2_test"},{"subj":"25698914-24681923-38235648","pred":"source","obj":"2_test"}]}],"config":{"attribute types":[{"pred":"source","value type":"selection","values":[{"id":"0_colil","color":"#eca993","default":true},{"id":"2_test","color":"#9396ec"}]}]}}