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How do you find saturation current?
2 Answers
- Measure current with fairly large reverse bias, to give you Is. ( for example, -20V for a 1N4148)
- Measure forward voltage with fairly large forward current (for example, 20mA for a 1N4148) and calculate the emission coefficient: n=VFVT⋅ln(I/IS)
What is saturation current in diode?
The saturation current is a combination of the generation current caused by thermal generation of electron hole pairs within the depletion region of the diode and the diffusion current due to minority carriers in the n and pregions diffusing across the depletion region.
What does saturation current depend on?
The saturation current depends on the intensity of the light,for a given frequency. More photons correspond to more electrons. One photon knock out one electron and if you increase the number of photons (or increase the intensity) you increase the current.
What is saturation current in this experiment?
The frequency and intensity of the incident light are kept constant. The positive voltage given to the anode is gradually increased and the corresponding value of the photocurrent is recorded. The maximum value of the photoelectric current is called the saturation current.
What is the origin of reverse saturation current?
The reverse saturation current is the part of the reverse current in a semiconductor diode which is caused by the diffusion of minority carriers from the neutral regions to the depletion region.
What causes a current flow in the saturation region?
MOS low-frequency small-signal model in the saturation region, showing gate (g), drain (d), and source (s) terminals. The bulk (b), or substrate, connection is also assumed, but not shown. The gmbvsb generator source causes a current flow proportional to bulk–source voltage vbs.
Is the drain bias independent of the saturation region?
For larger drain biases, the drain current saturates and becomes independent of the drain bias. Naturally, this region is referred to as the saturation region. The drain current in saturation is derived from the linear region current shown in equation 3.18, which is a parabola with a maximum occurring at VD, sat given by: 3
When is the transistor operating in the saturation region?
In Fig. 6B, with negligible gate current VGS= VDS so that the transistor is operating in the saturation region. When it is required that VGS ≠ VDS, the circuit in Fig. 6C may be used. As in the BJT case, in most amplifier applications RS is paralleled by a capacitor.
When does amplification occur in the saturation region?
In the saturation region of operation, amplification can occur since the drain current varies with VGS but (to first-order) does not vary with VDS. This region of operation is analogous to the forward-active region in bipolar transistors, where amplification can occur.