forward bias


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Related to forward bias: Reverse bias

forward bias

[¦fȯr·wərd ′bī·əs]
(electronics)
A bias voltage that is applied to a pn-junction in the direction that causes a large current flow; used in some semiconductor diode circuits.

bias

(1) A weight given to a neuron in a neural network. See neuron.

(2) A voltage applied to the gate (or base) of a transistor or vacuum tube, which causes the device to operate in its conductive state. When the control voltage (input voltage) is applied to the gate, it is added to the bias, causing the resultant voltage to be higher or lower, based on the sum of the two.

Forward and Reverse Bias
Forward bias voltage brings the transistor or tube into or closer to its conductive state. For example, if the gate requires positive voltage to conduct, forward biasing adds positive voltage.

In contrast, reverse bias holds the device in a non-conductive state until the sum of the control voltage and bias is sufficient to bring it to the conductive state. For example, if the gate requires positive voltage to conduct, reverse biasing adds negative voltage.

Bias is widely used in analog devices, such as an audio amplifier, to keep the input voltage within the conductive region of the transistor or tube. It is also used in digital circuits to reach a certain threshold and open or close the switch faster.


Transistor Conduction Curve
This is the typical conduction curve of a bipolar and field effect transistor (FET). A forward bias pushes the voltage past the transition region and keeps the transistor operating in its conduction region.
References in periodicals archive ?
As frequently reported, these cells yielded a higher PCE in reverse bias scans rather than in forward bias scans, likely due to the uprising of dynamic trapping and detrapping processes of charge carriers at the perovskite/ HTL and perovskite/ETL interfaces and to ion migration that alters the interfacial energy barriers and consequently modifies their height for the carrier collection [27].
Caption: Figure 8: Equivalent circuit diagram for a p-n junction with the intermediate layer of high resistance, constructed on the basis of an equivalent circuit pin diode (a) [49] and a simplified scheme for direct (forward bias) and inverse (reverse bias) connection (b).
In Figure 3(a), for unprocessed specimen, the friction force with a forward bias voltage was larger than that without a bias voltage.
Good correlation coefficients ([R.sup.2]) obtained from ln(J/V) versus [square root of V] plots reveal that the mechanism responsible for conduction in Ag/Pc/p-Si structures under forward bias conditions can be described by the Poole-Frenkel emission.
"We expect no action from the Fed or BOJ, although investors will be looking for a more dovish forward bias as the renewed decline in oil prices lowers inflation expectations globally," wrote strategists at Barclays.
2(a) and (b) plot the local density of states (LDOS) of the nanowire under 2.0 V and 3.1V forward bias voltage, respectively.
As seen from Scheme 1, under forward bias [Na.sup.+] and [Br.sup.-] ions can move through the opposite sides and the ions can pass through the interface of p- and n type gels to reach the opposite electrodes.
In other words, the threshold voltage and the forward bias current of the diode are the determinants in the rectifier's performance as well as its leakage current in reverse bias region, which play critical roles in the performance of the rectifier circuit.
This phenomenon takes place when the LED chip is powered, forward bias takes place at the p-n junction of the LED chip.
[3.] Breedon, Francis; Rime, Dagfinn; Vitale, Paolo (2010) A Transaction Data Study of the Forward Bias Puzzle, Discussion Paper 7791, CEPR
HPND 4005 PIN diode is used which has low series resistance, low capacitance, occupies less space and high frequency coverage (up to 12 GHz) as compared to other PIN diodes According to the HPND-4005 PIN diode datasheet [24], the resistor element in forward bias is equivalent to 4.7 [ohm] ([R.sub.S]) while the main capacitor element is 0.017 pF ([C.sub.T]) in the reverse bias state.

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