Voltage regulator

annex666 · 27th August 2003, 12:01 PM

I have a quick question about voltage regulators.

From what I have read most seem to be based around a differential system referencing the output voltage and a reverse-biased zener diode.

I was wondering if there are any commercial designs that use a precision voltage reference and a voltage follower (to accomodate the output current)?

I designed and simulated a discrete version of this idea based around zeners that are driven from zener referenced current sources cascaded in stages (I'm almost sure cascaded is not the correct terminology in circuit terms, but in logical terms it is correct). The circuit I tested had a very good SNR from what I remember.

To elaborate, a current source based on a zener reference voltage is used to source current for another zener - the voltage across which is used to reference the next current source and so on. Due to the steep I/V slope characteristics of the zener diode input voltage noise is reduced in each stage.

Does anyone know if commercial designs use this idea?
Are there many downsides?

jan.didden · 27th August 2003, 02:50 PM

I have seen many of those designs on this forum - look for something like "capacitance multiplier".
The significant difference between your circuit proposal and a regulator is that yours doesn't use overall feedback to regulate the output voltage - it really doesn't regulate in the normal sense of the term. It basically is a DC amplifier, amplifying the ref voltage, where-ever that comes from. The outp[ut will vary much more from varying the load then with a regulator. On the other hand, some have reported sonic advantages from the absence of overall feedback. The proof of the pudding is the eating.

Jan Didden

27th August 2003, 12:01 PM	#1
annex666 diyAudio Member Join Date: Jul 2002 Location: England	Voltage regulator I have a quick question about voltage regulators. From what I have read most seem to be based around a differential system referencing the output voltage and a reverse-biased zener diode. I was wondering if there are any commercial designs that use a precision voltage reference and a voltage follower (to accomodate the output current)? I designed and simulated a discrete version of this idea based around zeners that are driven from zener referenced current sources cascaded in stages (I'm almost sure cascaded is not the correct terminology in circuit terms, but in logical terms it is correct). The circuit I tested had a very good SNR from what I remember. To elaborate, a current source based on a zener reference voltage is used to source current for another zener - the voltage across which is used to reference the next current source and so on. Due to the steep I/V slope characteristics of the zener diode input voltage noise is reduced in each stage. Does anyone know if commercial designs use this idea? Are there many downsides? __________________ ...if it ain't broke don't fix it - make it BETTER!

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27th August 2003, 02:50 PM	#2
jan.didden diyAudio Member Join Date: May 2002 Location: Great City of Turnhout, Belgium Blog Entries: 6	I have seen many of those designs on this forum - look for something like "capacitance multiplier". The significant difference between your circuit proposal and a regulator is that yours doesn't use overall feedback to regulate the output voltage - it really doesn't regulate in the normal sense of the term. It basically is a DC amplifier, amplifying the ref voltage, where-ever that comes from. The outp[ut will vary much more from varying the load then with a regulator. On the other hand, some have reported sonic advantages from the absence of overall feedback. The proof of the pudding is the eating. Jan Didden