Mar 28, 2013 #1 R riie Newbie level 6 Joined Feb 7, 2013 Messages 14 Helped 0 Reputation 0 Reaction score 0 Trophy points 1,281 Activity points 1,378 Hi all, Is there any range of resistor values that should be used for an inverting op amp amplifier (Op27g)? A gain of -100 is required. Any reason why 20ohm and 2kohm combination doesn't work? Voltage output is seen to be saturated. Thanks!
Hi all, Is there any range of resistor values that should be used for an inverting op amp amplifier (Op27g)? A gain of -100 is required. Any reason why 20ohm and 2kohm combination doesn't work? Voltage output is seen to be saturated. Thanks!
Mar 28, 2013 #2 G godfreyl Advanced Member level 5 Joined Apr 18, 2012 Messages 1,974 Helped 632 Reputation 1,266 Reaction score 621 Trophy points 1,393 Activity points 12,772 riie said: Any reason why 20ohm and 2kohm combination doesn't work? Click to expand... The input impedance of the amplifier will be 20 Ohms, which is probably too low. What's it for?
riie said: Any reason why 20ohm and 2kohm combination doesn't work? Click to expand... The input impedance of the amplifier will be 20 Ohms, which is probably too low. What's it for?
Mar 28, 2013 #3 R riie Newbie level 6 Joined Feb 7, 2013 Messages 14 Helped 0 Reputation 0 Reaction score 0 Trophy points 1,281 Activity points 1,378 It is to amplifiy a voltage signal and be read by a daq. Which combination should I use instead? 1) 2k / 200k 2) 3.3k / 330k 3) 4.7k / 470k
It is to amplifiy a voltage signal and be read by a daq. Which combination should I use instead? 1) 2k / 200k 2) 3.3k / 330k 3) 4.7k / 470k
Mar 28, 2013 #4 FvM Super Moderator Staff member Joined Jan 22, 2008 Messages 52,404 Helped 14,749 Reputation 29,780 Reaction score 14,094 Trophy points 1,393 Location Bochum, Germany Activity points 298,026 2k feedback resistor is somewhat low, but may be suitable in some cases. The OP should be able to drive 2k at almost full swing. Output saturated suggests input overload or wrong bias. You usually want to measure all circuit voltages and analyze what's going wrong.
2k feedback resistor is somewhat low, but may be suitable in some cases. The OP should be able to drive 2k at almost full swing. Output saturated suggests input overload or wrong bias. You usually want to measure all circuit voltages and analyze what's going wrong.