摘要:
According to one embodiment, a memory is disclosed. The memory includes a differential sense amplifier that receives a data input and a complementary data input; and a switching mechanism, coupled to the amplifier, that switches the data input and the complementary data input to minimize a negative bias temperature instability (NBTI) effect on the amplifier.
摘要:
Post-manufacture compensation for a sensing offset can be provided, at least in part, by selectively exposing one of a pair of cross-coupled transistors in a sense amplifier to a bias voltage selected to cause a compensating shift in a characteristic of the exposed transistor. Such exposure may be advantageously provided in situ by causing the sense amplifier to sense values purposefully skewed toward a predominate value selected to cause the compensating shift. In some realizations, purposefully skewed values (e.g., value and value_1) are introduced directly into the sense amplifier. In some realizations, an on-chip test block is employed to identify and characterize sensing mismatch.
摘要:
Post-manufacture variation of timing may be employed to address data-dependent degradation or creep in device characteristics affecting a differential circuit. One particular example of such data-dependent degradation or creep involves Negative Bias Temperature Instability (NBTI). In certain memory circuit configurations, NBTI can cause threshold voltage (Vt) of PMOS devices to increase by an amount that depends on the historical amount of voltage bias that has been applied across gate and source/drain nodes. In the case of many sense amplifier designs, a predominant value read out using the sense amp may tend to disparately affect one device (or set of devices) as compared with an opposing device (or set of devices). In other words, if the same data value is read over and over again, then one of two opposing PMOS devices of a typical sense amp will accumulate an NBTI-related Vt shift, while the opposing PMOS device will accumulate little or no shift. The accumulated mismatch tends to cause an increase in the sense amp fail-point.