What is pass transistor meaning?
pass transistor (plural pass transistors) (electronics) A transistor used as a switch to pass logic levels between nodes of a circuit, instead of as a switch connected directly to a supply voltage.
How does pass transistor work?
An Example of Pass-Transistor Logic It is possible to use a single NMOS transistor as a PTL switch; the switch is considered closed when the voltage applied to the gate is logic high, and it is considered open when the voltage applied to the gate is logic low.
What is pass transistor in power supply?
The external pass transistor increases the available load current by creating an additional path from input to output. The path in this case was designed for an additional 150mA, but you can obtain larger output currents by substituting other components in the circuit.
What is pass transistor in CMOS?
Pass-Transistor Logic. A popular and widely-used alternative to complementary CMOS is pass-transistor logic, which attempts to reduce the number of transistors required to implement logic by allowing the primary inputs to drive gate terminals as well as source/drain terminals.
Why is it called a pass transistor?
In the context of linear voltage regulators, the pass element (transistor) is controlled by negative feedback to achieve regulation. Q1 passes output current in the direction of the arrow (and that is the reason it is called the pass transistor).
What is a pass element?
A circuit element (usually a transistor), in series with the load, that controls the output voltage by dropping a variable portion of the input voltage.
What are the advantages of pass-transistor logic?
The advantages of pass-transistor logic are the simple design, the reuse of already available signals, and the low contribution to static power. However, as against other types of logic, the x signals are not regenerated, instead, they are passed through an RC structure.
Why is only nMOS used in pass-transistor logic?
These techniques use only nMOS transistors in the pass network. The output logic level is restored using additional circuitry. The proposed designs require less silicon area, less power dissipation, and operate at higher speeds compared with the conventional CMOS pass-transistor networks.
What is pass transistor in voltage regulator?
In a linear voltage regulator, the pass transistor is the main element that is used to actually control the output voltage as the load current varies. As such, it acts like a variable resistance, regulating voltage by throwing away the excess as heat.
What is the function of the pass transistor in a linear voltage regulator circuit?
The pass transistor changes its pass through resistance to accommodate the changes in the resistance on the output, thus allowing more or less current to flow and consequently maintaining a constant voltage at the output.
Why is only NMOS used in pass transistor logic?
How many pass transistors can a pass transistor be driven through?
Explanation: Pass transistor input should not be driven through any other pass transistors because there occurs loss in logic levels. 7.
What is transmission gate logic?
A transmission gate (TG) is an analog gate similar to a relay that can conduct in both directions or block by a control signal with almost any voltage potential. It is a CMOS-based switch, in which PMOS passes a strong 1 but poor 0, and NMOS passes strong 0 but poor 1.
Why pass transistors are used?
Transistors are used as switches to pass logic levels between nodes of a circuit, instead of as switches connected directly to supply voltages. This reduces the number of active devices, but has the disadvantage that the difference of the voltage between high and low logic levels decreases at each stage.
What is pass transistor in VLSI?
In electronics, pass transistor logic (PTL) describes several logic families used in the design of integrated circuits. It reduces the count of transistors used to make different logic gates, by eliminating redundant transistors.
What is the difference between pass transistor and transmission gate design?
Transmission-Gate | Pass-Transistor-Logic i.e. NMOS devices passes a strong ‘0’ but a weak ‘1’ while PMOS transistors pass a strong ‘1’ but a weak ‘0’. The transmission gate combines the best of the two devices by placing an NMOS transistor in parallel with a PMOS transistor as shown in Figure below.
What is complementary pass-transistor logic?
A complementary pass-transistor logic (CPL) is proposed and applied to almost the entire critical path. The CPL consists of complementary inputs/outputs, an nMOS pass-transistor logic network, and CMOS output inverters.