Mutual compensation of mobility and threshold voltage temperature variations may result in a zero temperature coefficient bias point of a MOS transistor. The conditions under which this effect occurs, and stability of this bias point are investigated. Possible applications of this effect include voltage reference circuits and temperature sensors with linear dependence of voltage versus temperature. The theory is verified experimentally investigating the temperature behavior of a simple voltage reference circuit realized in 0.35-m CMOS process.

Schmitt trigger design with given circuit thresholds is described. The approach is based on studying the transient from one stable state to another when the trigger is in linear operation. The trigger is subdivided into two subcircuits; each of them is considered as a passive load for the other. This allows the relations governing the deviations of the circuit thresholds from their given values to be obtained. The trigger device sizes are thus determined by the threshold tolerances.

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A method for wireless, non-contact testing of semiconductor wafers is presented. The technology applies to chips with active electronics, including standard integrated circuits (ICs), which require testing at the wafer level. The technology relies on short-range, near field communications to transfer data at gigabit per second rates between the probe card and the device under test (DUT) on a wafer. The probe consists of a CMOS device with micro antenna structures and transceiver circuits. Each antenna and transceiver circuit is capable of probing one input/output (I/O) site on the DUT. Each I/O site on the DUT is connected to a single antennae and transceiver circuit, which is designed into the DUT. The antennae and transceiver circuits can be incorporated into the DUT without any impact on performance or real estate. The main advantage of non-contact wafer probing is higher reliability (less retest, no pad scrub marks), added functionality (higher test frequencies at higher pin densities), and increased throughput (higher parallelism, reduced alignment tolerance, less maintenance, and less downtime). The wireless probes interface to standard automated test equipment (ATE) while all antenna structures and electronics needed on the DUT are fully CMOS compliant.