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Topic: supply voltage to op amp (Read 379 times) previous topic - next topic

ppstar

my question is a very basic one as i am new to using op amps.is it that the op amps shows the output only when it is supplied with the (baised) voltage as mentioned in its dasheet.for eg icLM741 has supply voltage as 18V.so it wont show anything till it is supplied with 18V???..i have only 15v supply voltage instrument available with me.pls advice

afremont

15V is plenty of voltage to power a 741.  If you are using a single supply voltage, the op-amp won't have output until the voltage applied to the + input is higher than the voltage at the - input.
Experience, it's what you get when you were expecting something else.

astrofrostbyte

The lm741  needs a supply voltage between V+ and V-  of at least 10Volts  and max ~44 Volts.
All you input pins and output pin of the opamp must be within these voltages,   since the lm741 is not a so called Rail-2-rail capable opamp there is a margin you must stay away from the supply voltages (normally a few volts).

There is tons of explainations of how opamps work online, with nice graphics and so ,  its hard to top such info here in a forum.
Gear: Arduino- Uno,Due,Ethernet,  OLS, Buspirate, J-Link, TDS1002, Rigol DG1022

dc42

Take a close look at the datasheet. In the section called "Absolute maximum ratings" you will find the supply voltage that you must not exceed. Under "Recommended operating conditions" you will find a supply voltage range listed, which is the range of supply voltages over which the device is guaranteed to work.

With Arduino it is common to use single-supply op amps such as the LM358. This one can be used with a supply voltage anywhere between 3V and 32V.
Formal verification of safety-critical software, software development, and electronic design and prototyping. See http://www.eschertech.com. Please do not ask for unpaid help via PM, use the forum.

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