My pleasure. Glad that you liked this bandgap circuit video. Here are a few related videos: Bandgap Voltage with Op Amp & Widlar Current Mirror Circuit th-cam.com/video/esMlNx5w9Jw/w-d-xo.html Voltage Regulator Design with BJT Darlington Transistors and Zener Diodes th-cam.com/video/ArisQp7V0Ac/w-d-xo.html I hope these videos are interesting as well. 🙏
You are very welcome. Glad that my circuit videos are useful. Here are a few related videos: Bandgap Voltage with Op Amp & Widlar Current Mirror Circuit th-cam.com/video/esMlNx5w9Jw/w-d-xo.html Voltage Regulator Design with BJT Darlington Transistors and Zener Diodes th-cam.com/video/ArisQp7V0Ac/w-d-xo.html I hope these videos are interesting as well. 🙏
Nice presentation. It would be nicer if you could carry the literals up to the end of the derivation of the actual result(s), and then replacing the values. The analysis of a particular result and pre-requisites/simplifications (betas, and so on) could be carried out with a separate annotation and be left somewhere until the presentation's end. I would point out that the actual diode bandgap is also a function of temperature (eg. Varshni semiempirical formulation), possibly out of the scope of the presentation. Thanks for your time.
@_nemo174 Glad that you liked this BandGap video. And thanks for your suggestion and for pointing out the fact that actual PN junction band-gap is not absolutely independent of junction temperature. I would say, practically speaking, it is safe to neglect its thermal dependency at least for the range of practical applications that matter in this context. For example, a bandgap voltage reference Diode with coefficient temperature of say +/- 0.003% per degree kelvin is at least an order of magnitude less temperature sensitive than Zener diodes. If nominal bandgap voltage is ~1.28 volt, then such a small temperature coefficient translates to a mere 0.00003*1.28 volt ~= 38.4 micro volt change per degree which means ~1mV change (practically negligible) even if junction temperature changes 30 degree Celsius. For more related circuit examples please see: Bandgap Voltage with Op Amp & BJT Widlar Current Mirror Circuit th-cam.com/video/esMlNx5w9Jw/w-d-xo.html Voltage Regulator Design with BJT Darlington Transistors and Zener Diodes th-cam.com/video/ArisQp7V0Ac/w-d-xo.html I hope these circuit examples are interesting as well. Thanks again for your comment. 🙏
So in nutshell: T1 & T2 produces inverse temperature coef than Vbe, thus compensates T3; and T4, wired identically to T2, also has it to compensate T6. But what compensates temp coef of T5 Vbe then? Does this additional current mirrors you mentioned in the end do?
Thanks for watching, sharing your thoughts and asking questions. In this Band-gap voltage reference the series connection of VBE3 and R2 sets and defines the voltage drop Vdiode across the top and bottom rails of the circuits. The collector-emitter voltages (Vce) of BJT transistors T3, T4 and T5 will adjust accordingly to accommodate the forced voltage by the sum of R2.I2 and VBE3. Two related circuit videos are, Bandgap Voltage with Op Amp & Widlar Current Mirror Circuit th-cam.com/video/esMlNx5w9Jw/w-d-xo.html Voltage Regulator Design with BJT Darlington Transistors and Zener Diodes th-cam.com/video/ArisQp7V0Ac/w-d-xo.html I hope this explanation is helpful.
How does a Bandgap voltage reference diode work? What is the value of output voltage? What should be the choice of circuit components to ensure near zero temperature coefficient for this reference diode so that generated output voltage doesn't change with temperature? These questions are discussed and answered in this bandgap reference voltage design example and tutorial. For additional circuit examples see: 5v Charger Voltage Regulator with MOSFET, JFET & Temperature Compensation th-cam.com/video/NdfyHoxjKrY/w-d-xo.html Voltage Regulator Design with BJT Darlington Transistors and Zener Diodes th-cam.com/video/ArisQp7V0Ac/w-d-xo.html More example are posted in the Analog Circuits video playlist th-cam.com/play/PLrwXF7N522y4c7c-8KBjrwd7IyaZfWxyt.html. I hope these analog examples are useful and interesting. Thanks for watching.
@uvx508 Glad that you liked this bandgap voltage reference diode. For more related circuit examples please see: Bandgap Voltage with Op Amp & BJT Widlar Current Mirror Circuit th-cam.com/video/esMlNx5w9Jw/w-d-xo.html
Excellent explanation. Keep up with the good work.
My pleasure. Glad that you liked this bandgap circuit video. Here are a few related videos:
Bandgap Voltage with Op Amp & Widlar Current Mirror Circuit th-cam.com/video/esMlNx5w9Jw/w-d-xo.html
Voltage Regulator Design with BJT Darlington Transistors and Zener Diodes th-cam.com/video/ArisQp7V0Ac/w-d-xo.html
I hope these videos are interesting as well. 🙏
This was a high level and top quality explanation. Thank you for your videos. 😊
You are very welcome. Glad that my circuit videos are useful. Here are a few related videos:
Bandgap Voltage with Op Amp & Widlar Current Mirror Circuit th-cam.com/video/esMlNx5w9Jw/w-d-xo.html
Voltage Regulator Design with BJT Darlington Transistors and Zener Diodes th-cam.com/video/ArisQp7V0Ac/w-d-xo.html
I hope these videos are interesting as well. 🙏
Nice presentation. It would be nicer if you could carry the literals up to the end of the derivation of the actual result(s), and then replacing the values. The analysis of a particular result and pre-requisites/simplifications (betas, and so on) could be carried out with a separate annotation and be left somewhere until the presentation's end.
I would point out that the actual diode bandgap is also a function of temperature (eg. Varshni semiempirical formulation), possibly out of the scope of the presentation.
Thanks for your time.
@_nemo174 Glad that you liked this BandGap video. And thanks for your suggestion and for pointing out the fact that actual PN junction band-gap is not absolutely independent of junction temperature. I would say, practically speaking, it is safe to neglect its thermal dependency at least for the range of practical applications that matter in this context. For example, a bandgap voltage reference Diode with coefficient temperature of say +/- 0.003% per degree kelvin is at least an order of magnitude less temperature sensitive than Zener diodes. If nominal bandgap voltage is ~1.28 volt, then such a small temperature coefficient translates to a mere 0.00003*1.28 volt ~= 38.4 micro volt change per degree which means ~1mV change (practically negligible) even if junction temperature changes 30 degree Celsius. For more related circuit examples please see:
Bandgap Voltage with Op Amp & BJT Widlar Current Mirror Circuit th-cam.com/video/esMlNx5w9Jw/w-d-xo.html
Voltage Regulator Design with BJT Darlington Transistors and Zener Diodes th-cam.com/video/ArisQp7V0Ac/w-d-xo.html
I hope these circuit examples are interesting as well. Thanks again for your comment. 🙏
So in nutshell: T1 & T2 produces inverse temperature coef than Vbe, thus compensates T3; and T4, wired identically to T2, also has it to compensate T6. But what compensates temp coef of T5 Vbe then? Does this additional current mirrors you mentioned in the end do?
Thanks for watching, sharing your thoughts and asking questions. In this Band-gap voltage reference the series connection of VBE3 and R2 sets and defines the voltage drop Vdiode across the top and bottom rails of the circuits. The collector-emitter voltages (Vce) of BJT transistors T3, T4 and T5 will adjust accordingly to accommodate the forced voltage by the sum of R2.I2 and VBE3. Two related circuit videos are,
Bandgap Voltage with Op Amp & Widlar Current Mirror Circuit th-cam.com/video/esMlNx5w9Jw/w-d-xo.html
Voltage Regulator Design with BJT Darlington Transistors and Zener Diodes th-cam.com/video/ArisQp7V0Ac/w-d-xo.html
I hope this explanation is helpful.
How does a Bandgap voltage reference diode work? What is the value of output voltage? What should be the choice of circuit components to ensure near zero temperature coefficient for this reference diode so that generated output voltage doesn't change with temperature? These questions are discussed and answered in this bandgap reference voltage design example and tutorial. For additional circuit examples see: 5v Charger Voltage Regulator with MOSFET, JFET & Temperature Compensation th-cam.com/video/NdfyHoxjKrY/w-d-xo.html
Voltage Regulator Design with BJT Darlington Transistors and Zener Diodes th-cam.com/video/ArisQp7V0Ac/w-d-xo.html
More example are posted in the Analog Circuits video playlist th-cam.com/play/PLrwXF7N522y4c7c-8KBjrwd7IyaZfWxyt.html. I hope these analog examples are useful and interesting. Thanks for watching.
Interesting
@uvx508 Glad that you liked this bandgap voltage reference diode. For more related circuit examples please see:
Bandgap Voltage with Op Amp & BJT Widlar Current Mirror Circuit th-cam.com/video/esMlNx5w9Jw/w-d-xo.html