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When the transistor is in saturation the collector to emitter voltage is?
Transistor datasheets will define this voltage as CE saturation voltage VCE(sat) — a voltage from collector to emitter required for saturation. This value is usually around 0.05-0.2V. This value means that VC must be slightly greater than VE (but both still less than VB) to get the transistor in saturation mode.
What is transistor saturation voltage?
“Saturation” in a transistor switch circuit is achieved when the voltage across the collector/ emitter (VCE(sat)) is less than or equal to . 1 to . 3 volts – depending on the type of transistor. At that voltage point, the transistor appears to act like a simple SPST mechanical switch that has been closed (On).
How to calculate the saturation of a transistor?
Divide the maximum collector current (I C) by the minimum current gain (h FE) at that collector current. For example, say I C (max) = 30 mA and h FE (min) = 83 at I C = 30 mA. The result is that I B (nominal) is about 360 µA. Multiply I B (nominal) by a “saturation factor” – a number between 2 and 10 – to ensure that the transistor saturates.
Can a transistor be used as a driver for an led?
An LED driver is an electronic circuit that utilises a transistor to switch power to an LED. Usually, the signal from a microcontroller, or logic gate, does not possess sufficient drive current to power an LED directly. If the LED has a higher power requirement, then it is best to use an NPN transistor as a driver.
When do you use a bipolar junction transistor?
When a bipolar junction transistor (BJT) is used to switch a load (e.g. a relay, an LED, a buzzer, a small motor, etc) ON and OFF, it is most often operated as a “saturated switch”. This article explains saturation in BJTs – why it is used, and how to calculate the base resistor to ensure saturation.
What is the forward bias voltage of a transistor?
Assuming the transistor conducts fully in saturation, there will be negligible resistance across its emitter-collector junctions, and therefore the voltage across the series resistor RL will be 3.3 V. This is very simple to deduce because the forward bias voltage of the LED is 1.7 V,…