opa 2889 buffer circuit

kp93300 · 16th October 2012, 03:35 PM

Hi
I need some advice
See the schematic attached . This is from the datasheet of the opa2889.
The link for the datasheet is

http://www.ti.com/lit/ds/symlink/opa2889.pdf

I wish to use this op amp as buffer after a dac and before the amp. .
What does the label of V0 -DIS imply ?
If I want unity gain ,do i short R3?

much appreciated .
kp93300

peranders · 16th October 2012, 04:11 PM

Quote:

Leaving this disable pin open, or holding it HIGH, operates the OPA2889 normally. If pulled LOW, the OPA2889 supply current drops to less than 20μA/ch while the output goes into a high-impedance state.

You didn't read the datasheet, first page?

kp93300 · 17th October 2012, 12:45 AM

Hi peranders
thanks for the info.
I read but i do not understand !

I am thinking of buying a few to play with it.

thanks

kp93300

peranders · 17th October 2012, 05:23 AM

What is means is if you let this pin be unconnected, the opamp will work as expected. If you ground this pin the opamp will be shut off and also the output stage. In your case I'll suppose you should forget this pin.

AndrewT · 17th October 2012, 11:06 AM

Quote:

Originally Posted by kp93300

........... I want unity gain ,do i short R3?...............

What does the datasheet say?

That may be a clue to whether it can be used as a buffer.

kp93300 · 17th October 2012, 01:38 PM

Hi
thanks peranders and Andrew
The datasheet says it is unity gain stable,
I quote from the datasheet

1FEATURES
2• FLEXIBLE SUPPLY RANGE:
+2.6V to +12V Single Supply
± 1.3V to ± 6V Dual Supplies
• UNITY-GAIN STABLE
• WIDEBAND ± 5V OPERATION: 60MHz
(G = +2V/V)
• OUTPUT VOLTAGE SWING: ± 4V
• HIGH SLEW RATE: 250V/ µ s
• LOW QUIESCENT CURRENT: 460 µ A/ch
• LOW DISABLE CURRENT: 18 µ A/ch

thanks

kp93300

17th October 2012, 05:23 AM	#4
peranders Electrons are yellow and more is better! diyAudio Member Join Date: Apr 2002 Location: Göteborg, Sweden Blog Entries: 4	What is means is if you let this pin be unconnected, the opamp will work as expected. If you ground this pin the opamp will be shut off and also the output stage. In your case I'll suppose you should forget this pin. __________________ /Per-Anders (my first name) or P-A as my friends call me Tube Buffered Gainclone in work \|Thread

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
FS: opa 2134ua, opa 134ua, opa 2604ua	supernet	Swap Meet	0	19th August 2011 03:54 PM
FS: Audio-gd OPA Moon Dual Opa	gabanyayaya	Swap Meet	1	28th May 2010 06:14 PM
OPA-Earth & OPA-Sun, Discrete Opamp diy kits	lineup	Solid State	38	25th February 2009 05:40 PM
What's the different between OPA-541AM, OPA-541AP and OPA-549T	100db	Chip Amps	1	7th September 2006 03:26 AM
Amp Circuit of Opa+Mosfet/normal transistors.	Dj BASS AMP	Solid State	1	23rd May 2004 05:33 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

17th October 2012, 12:45 AM	#3
kp93300 diyAudio Member Join Date: Mar 2007	Hi peranders thanks for the info. I read but i do not understand ! I am thinking of buying a few to play with it. thanks kp93300

17th October 2012, 01:38 PM	#6
kp93300 diyAudio Member Join Date: Mar 2007	Hi thanks peranders and Andrew The datasheet says it is unity gain stable, I quote from the datasheet 1FEATURES 2• FLEXIBLE SUPPLY RANGE: +2.6V to +12V Single Supply ± 1.3V to ± 6V Dual Supplies • UNITY-GAIN STABLE • WIDEBAND ± 5V OPERATION: 60MHz (G = +2V/V) • OUTPUT VOLTAGE SWING: ± 4V • HIGH SLEW RATE: 250V/ µ s • LOW QUIESCENT CURRENT: 460 µ A/ch • LOW DISABLE CURRENT: 18 µ A/ch thanks kp93300