Digital CMOS Abbreviation O Alphabet Dictionary
Observability (Testing)
In testing, observability refers to the ability to observe the state of an internal node within a circuit. If an internal node is not directly accessible through an output pin, it is considered unobservable. Improving observability often involves bringing internal nodes to output ports while managing the number of pins effectively.
Observation
Observation refers to the output of a unit under test when subjected to a test vector. The observed output may match the expected result, indicating that the unit is fault-free, or it may differ, indicating a detected fault. Observation is critical for assessing the functionality of components.
Ohmic Contact
An ohmic contact is a metal-semiconductor junction where conduction occurs in either direction with relatively constant resistance. This type of contact is achieved by heavily doping the semiconductor, leading to extreme band bending that enables current flow through tunneling.
Omega FET
Omega FET is a variation of FinFETs in which the transistor channel is constructed as a full cylinder attached at the bottom to the wafer. While providing more gate control over the channel, omega structures can be more challenging to fabricate than fins.
Operator (VHDL)
In VHDL, an operator is a manipulator used on a set of operands. Operators can be unary or binary and can perform various functions such as arithmetic operations, shifting, logical operations, and more. These operators can be redefined and overloaded to handle different types and data.
Output High Voltage
Output high voltage represents the nominal or “clean” electrical output of a logic gate that corresponds to logic “1”. It is defined as the output of the gate when the input is equal to the gate’s output low voltage, assuming clean input values match clean output values within the same gate family.
Output Low Voltage
Output low voltage represents the nominal or “clean” electrical output of a logic gate that corresponds to logic “0”. It is defined as the output of the gate when the input is equal to the gate’s output high voltage, under the assumption that clean input values match clean output values within the same gate family.
Overglass
Also known as a passivation layer, overglass is the topmost layer of an integrated circuit. It consists of a thick layer of silicon dioxide, and only bonding pads break through this layer. Overglass provides protection against contamination and mechanical damage.
Overloading
Overloading is a programming concept where a function or procedure is defined multiple times with unique sets of arguments. It allows a single function to handle different argument types or numbers, improving code flexibility.
Oxidation
Oxidation is the process of growing silicon dioxide (oxide) from silicon by exposing silicon to oxygen or water vapor and heat. The rate of oxide growth depends on factors like precursor concentration, temperature, and time.
Oxide Capacitance
Oxide capacitance refers to the capacitance of a MOSFET oxide layer per unit area. It is determined by the permittivity (dielectric constant) of the oxide material and its thickness.
Oxide Potential
Oxide potential represents the amount of band tilting on the oxide of an MOS capacitor. It is influenced by the applied gate-to-body potential and is zero in the flat band condition. Most of the differential gate potential in strong inversion falls on the oxide.
