Low Temp Drift VRef (Zener?)

Kashmire · 13th January 2004, 12:40 AM

I need a voltage reference for my output stage bias circuit. I could use a zener diode, but the voltage drift with temperature is very bad. In addition, zeners are noisy.

Any comments on a VRef that is not senstive to temperature?

Steven · 13th January 2004, 10:20 AM

Zeners or not that noisy. You can use them for biasing of output stages. The temp coeff. of low voltage zeners is negative, of high voltage zeners positive, and around 5.6V it is almost zero.

For very low temp coeff. use a regulator based on a bandgap instead of a zener.

Steven

johnferrier · 13th January 2004, 10:45 AM

The LTZ1000 is pretty good.

http://www.linear.com/pdf/1000afas.pdf

JF

CheffDeGaar · 13th January 2004, 01:32 PM

I remember Elektor publishing a (theoretically) T° independent discrete Vref (2 or 3 BJTs) Will try to dig it out...

In the meantime, have a look at National's LM199 (1ppm/°C, with builtin heater and temp stabilizer) and at companion app notes too :

http://www.national.com/ds/LM/LM199.pdf
http://www.national.com/an/AN/AN-161.pdf
http://www.national.com/an/AN/AN-184.pdf

Cheers

13th January 2004, 12:40 AM	#1
Kashmire diyAudio Member Join Date: Dec 2003 Location: Midwest	Low Temp Drift VRef (Zener?) I need a voltage reference for my output stage bias circuit. I could use a zener diode, but the voltage drift with temperature is very bad. In addition, zeners are noisy. Any comments on a VRef that is not senstive to temperature?

13th January 2004, 01:32 PM	#4
CheffDeGaar diyAudio Member Join Date: Feb 2003 Location: This Universe, I think	I remember Elektor publishing a (theoretically) T° independent discrete Vref (2 or 3 BJTs) Will try to dig it out... In the meantime, have a look at National's LM199 (1ppm/°C, with builtin heater and temp stabilizer) and at companion app notes too : http://www.national.com/ds/LM/LM199.pdf http://www.national.com/an/AN/AN-161.pdf http://www.national.com/an/AN/AN-184.pdf Cheers __________________ /Cheff - Falling feels like flying, until you hit the ground

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
SAA7323 Vref pin?	jnewbold	Digital Source	0	16th September 2008 02:35 AM
temp drift in MOSFET Vgs	SemperFi	Solid State	6	29th June 2006 04:50 PM
amp upgrade and small fault - drift with ambient temp.	Pulse-R	Solid State	0	2nd May 2006 09:57 AM
Passive I/V Vref	dsavitsk	Digital Source	4	22nd November 2005 02:07 PM
VREF as volume control	Prune	Digital Source	7	22nd April 2004 09:27 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

13th January 2004, 10:20 AM	#2
Steven diyAudio Member Join Date: Oct 2003 Location: The Netherlands	Zeners or not that noisy. You can use them for biasing of output stages. The temp coeff. of low voltage zeners is negative, of high voltage zeners positive, and around 5.6V it is almost zero. For very low temp coeff. use a regulator based on a bandgap instead of a zener. Steven

13th January 2004, 10:45 AM	#3
johnferrier diyAudio Member Join Date: Sep 2003 Location: WA	The LTZ1000 is pretty good. http://www.linear.com/pdf/1000afas.pdf JF