Body Built-In Cells for Detecting Transient Faults and Adaptively Biasing Subcircuits

Abstract

Integrated circuit (IC) system reliability, security, and power issues are highly associated and related to the operating frequency, voltage, and body bias level. Modern strategies of reliability, security, and power management that considers adaptive body biasing (ABB) are either able to reduce soft error rate by forward body biasing or increase it by applying reverse body biasing. Hence, ABB strategies demand additional mechanisms to compensate and mitigate the effects of radiation-induced transient faults that may generate soft errors. This chapter discusses a special cell that merges and optimizes the abilities of a body built-in current sensor (BBICS) with the level-shifter (LS) function of body-bias generators. Jointly considered, BBICS and LS form thus a single body built-in cell that is fundamental for ABB strategies to: (1) detect short-to-long-duration transient faults; (2) control transistor threshold voltage, thereby eventually compensating alterations induced by aging or process, voltage, and temperature (PVT) variations; (3) optimize IC system trade-off between power and delay. The design of a single built-in cell with multiple purposes allows further reducing the already low area overhead imposed by the BBICS and LS circuitries.