What is subthreshold leakage current in CMOS?

What is subthreshold leakage current in CMOS?

Subthreshold conduction or subthreshold leakage or subthreshold drain current is the current between the source and drain of a MOSFET when the transistor is in subthreshold region, or weak-inversion region, that is, for gate-to-source voltages below the threshold voltage.

What causes subthreshold leakage?

Subthreshold leakage current is mainly due to drain-induced barrier lowering or DIBL. In short channel devices, the depletion region of drain and source interact with each other and reduce the potential barrier at the source.

How subthreshold leakage is affecting the performance of MOS transistor?

Subthreshold leakage current in an nMOS transistor It is evident from (4) that the subthreshold leakage current is a strong function of the threshold voltage of a MOS transistor. This leakage current is highly undesirable in a digital circuit in deep submicron and nanoscale technologies.

What is a subthreshold?

Definition of subthreshold : inadequate to produce a response subthreshold dosage a subthreshold stimulus.

What is a subthreshold stimulus?

Sub-threshold (or subthreshold) refers to a stimulus that is too small in magnitude to produce an action potential in excitable cells. In general, a sub-threshold stimulus leads to the depolarization of the membrane, but the magnitude of the depolarization is not large enough to reach the threshold voltage.

What does subthreshold mean?

inadequate to produce a response
Definition of subthreshold : inadequate to produce a response subthreshold dosage a subthreshold stimulus.

What is leakage current in MOS?

leakage current is defined as the current that “leaks” between drain and source (D/S) of a MOSFET when the device is OFF, i.e, its Vgs is below the device threshold voltage.

What is a subthreshold response?

What is subthreshold operation?

In effect, subthreshold operation applies the leakage of the transistor as it begins to turn on to charge the capacitance of the downstream logic. The growth in the contribution to power from leakage is due to the massive increase in switching time of the transistor.

What is subthreshold and Suprathreshold?

If you drop a pebble in a lake to create one wave, that’s like your threshold stimulus. If you drop a heavy rock, you could get several ripples and that’s like a suprathreshold stimulus. Another Analogy: If something tickles your nose but it’s not enough to make you sneeze, that’s a subthreshold stimulus.

What is subthreshold and threshold?

What is an example of a subthreshold?

Another Analogy: If something tickles your nose but it’s not enough to make you sneeze, that’s a subthreshold stimulus. If something tickles your nose just enough to make you sneeze once, that’s a threshold stimulus.

Why is subthreshold slope important?

The steeper subthreshold slope permits a lower Vt for the same off-current, which in turn allows the devices to be used at lower supply voltages thereby attracting attention for low power operation.

Why subthreshold swing is important?

Subthreshold swing should normally be minimized when it is allowed by the application. Small subthreshold swing means better channel control, e.g. improved Ion/Ioff, which usually means less leakage, and less energy. For subthreshold circuits it also means better performance.

What is acceptable leakage current?

To provide a margin of safety for the consumer, regulatory agencies usually require that a product exhibit a line voltage leakage current of less than 0.5mA. With some products equipped with 3-prong plugs and warning stickers, the permissible leakage current may be as high as 0.75mA, but the typical limit is 0.5mA.

What is meant by subthreshold slope?

The subthreshold slope is a feature of a MOSFET’s current–voltage characteristic. In the subthreshold region, the drain current behaviour – though being controlled by the gate terminal – is similar to the exponentially decreasing current of a forward biased diode.