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Meaning of BJT Vce(sat)

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ccw27

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vce saturation voltage

What is the meaning of Vce(sat)? If Vce(sat) of a BJT is 0.6V does it mean that the Vce must exceed 0.6V to ensure the transistor is in active region?

Thanks
 

vce saturation

When the BJT is in the saturation, the Vce(sat) means the voltage difference between the Collector and Emitter at the spec. "Ic" current value. The value of Vce(sat) have relation to Ic(sat) and the collector resistance "rc".
 

vce sat

Sorry I did not understand. BJT in saturation == MOS in triode. So if Vce exceeds Vce(sat) the BJT will be in active region?
 

bjt vce

vce in saturation i dealy dosnt have any relation with ic.but at saturation if ic is more ur vce sat also tends to increace
 

vcesat

It seems Vce,sat is not equivalent to Vd,sat in MOS case. Or is it?
 

bjt vce sat

Vce(sat) is analogous to Vds(sat)
 

bjt vce saturation

vce sat is the bjt maintain in active .
 

vce(sat)

it means that the voltage of Vce is 0.6 in saturation mode of bjt.
if
Ibβ>Ic BJT is in saturation
in active region
Ib = βIc

remove the bjt from the circuit then calculate the voltage across Vbe if Vbe is smaller than 0.7 (or threshold voltage of bjt) the BJT is in cutoff mode
 

vce bjt transistor

ccw27,
A BJT is saturated when both junctions are forward biased. For example in an NPN transistor, the device is saturated when the collector to emitter voltage is less than the base-emitter voltage. Vce(sat) is specified with at a specific value of collector current, and a specific value of base current. Typically the base current is one tenth the collector current.
Regards,
Kral
 

pnp bjt vce

BJT is in sat when Ic<(β×Ib).
for a BJT is to in saturation, we have to apply Vbe atleast .75V .
We have
σ = (Ic÷βIb)
When σ<1, then we say BJT is in Saturation.
As the value of σ becomes less than 1 i.e. σ<<1
BJT goes deeper in to saturation.
Generally, Vce(Sat) is 0.1V or 0.2V
Vce(sat) is directly proportionally to Vt(=Thermal Voltage)

Cheers

Puneet Bansal :idea:

Added after 3 minutes:

aersoy said:
it means that the voltage of Vce is 0.6 in saturation mode of bjt.
if
Ib>=βIc BJT is in saturation
in active region
Ib = βIc

remove the bjt from the circuit then calculate the voltage across Vbe if Vbe is smaller than 0.7 (or threshold voltage of bjt) the BJT is in cutoff mode
Click to expand...



My Dear friend

u hv written Ib>=βIc !

It is wrong dear.

we have Ic=βIb

for further enquiry
check my answer below !

CHEERS

Puneet Bansal
 

bjt vce when on

puneet bansal said:
BJT is in sat when Ic<(β×Ib).
for a BJT is to in saturation, we have to apply Vbe atleast .75V .
We have
σ = (Ic÷βIb)
When σ<1, then we say BJT is in Saturation.
As the value of σ becomes less than 1 i.e. σ<<1
BJT goes deeper in to saturation.
Generally, Vce(Sat) is 0.1V or 0.2V
Vce(sat) is directly proportionally to Vt(=Thermal Voltage)

Cheers

Puneet Bansal :idea:

Added after 3 minutes:

aersoy said:
it means that the voltage of Vce is 0.6 in saturation mode of bjt.
if
Ib>=βIc BJT is in saturation
in active region
Ib = βIc

remove the bjt from the circuit then calculate the voltage across Vbe if Vbe is smaller than 0.7 (or threshold voltage of bjt) the BJT is in cutoff mode
Click to expand...



My Dear friend

u hv written Ib>=βIc !

It is wrong dear.

we have Ic=βIb

for further enquiry
check my answer below !

CHEERS

Puneet Bansal
Click to expand...
yes ur rigth i wrote the formula wrong and i am correcting the mistke
as
in saturation
βIb>Ic
i didnot write the correct formula although i know it as well as my name :D
 

vce of a bjt

From my understanding - the saturation voltage for given current through BJT collector- emitter and base emitter, is the Vce value such as any further increase of BJT base current wont be resulted in Vce decrease (i dont mean destruction ).

You can use voltage above Vce-sat as active region , but keep it mind more nonlinear behavior of BJT at voltages near Vce-sat.
 

Re: vce of a bjt

Vce saturation means Ic is at its maximum value(saturated). Ideally we consider Vce to be zero but in actual it is 0.2 to 0.3 volts for upto 50 mA Ic. Note that saturation of Ic is determined by Rc. For example if Vcc is 20V and Rc is 1K ohms then Ic saturation 20V/1K = 20mA and if Vcc is 30V and Rc is 1K ohms then Ic saturation 30V/1K = 30mA.
It means increase Ic upto maximum limit which is given in data sheet for example Ic max for 2N3904 is 200mA.
Saturation means a value that cannot be further increased.
 

Vce(sat) at a rating current gives you an indication of how
efficient a power switch the device is. If the Rc is high you
will have much more Vce(sat) under load. However switching
transistors may also have higher Vce(sat) due to features
that are meant to limit base charge storage, even if Rc is
relatively low.

In any case, "how low is low" is always a useful answer.

Saturation certainly does not mean the collector current
is at its maximum. It is more the maximum that the load
can provide, not what the transistor could draw. If you
gave it more voltage it would draw plenty more current.
In saturation (for a given base current) you will be drawing
less than in the normal forward active region.
 

Saturation is just a point indicating that Ic will not further increase or decrease with increase in Ib. Saturation point can be moved up and down with increase in Vcc or decrease in Rc. For example if a transistor has maximum current rating of 200mA then it saturation point or Ic can be fixed to any value up to 200mA.
Saturation means in terms of transistor a value that cannot be further increased or decreased i.e Ic value will not increase or decrease (down to saturation region - up to breakdown region).
 

Hello friends,

Can someone pls reply this question for me as I am in urgent need for the right option.

19.In what range of voltages is the transistor in the linear region of its operation?
A.0 < VCE < 0.7 V
B.0.7 < VCE < 1.4 V
C.0.7 < VCE < VCE(max)
D.0 < VCE < VCE(max)
 

Re: vce sat

ccw27 said:
Sorry I did not understand. BJT in saturation == MOS in triode. ..............................
Click to expand...
Yes that's true. It's confusing but the MOS saturated operation is equivalent to the BJT active region. The BJT saturated region is part of the MOSFET linear (triode) region. Just something they did to keep you on your toes.

The definition of BJT saturated is that both the base-emitter and collector emitter junctions are forward biased (Vce is equal to or less then Vbe). For full saturation and minimum Vce the base current is typically set equal to or greater than 1/10 of the collector current.

Originally posted by wky​

Vce(sat) is analogous to Vds(sat)​
Click to expand...
No. Vce(sat) is similar to Vds in the FET linear region with a large Vgs voltage (well above the Vgs(thres). See above
 

Microelectronic Circuit Design, R.C. Jaeger:

It is important to note that the saturation region of the bipolar transistor does NOT correspond to the saturation region of the FET.
This unfortunate use of terms is historical in nature and something we just have to accept.
 

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