How LM358 op amp can work with only one voltage source?

Thread Starter

rumpler

Joined Mar 22, 2019
9
Hi everyone

I like to know why lm358 can work with 0V in his -Vcc and other op-amp can't? for example lm741 can get there only voltage between -5 to -15 volt
When I looked on the schematic level I see no different between this two..

thank u a lot
 

Ylli

Joined Nov 13, 2015
799
Look again. First of all, the 741 uses NPN transistors on the input, and with the bases of the input diff pair grounded, requires a negative voltage on the emitters to put the transistors into a active state. The 358 uses PNP input transistors and can be properly biased without the negative supply.
 

ian field

Joined Oct 27, 2012
6,539
Hi everyone

I like to know why lm358 can work with 0V in his -Vcc and other op-amp can't? for example lm741 can get there only voltage between -5 to -15 volt
When I looked on the schematic level I see no different between this two..

thank u a lot
Vague recollection that the 358 might be DESIGNED for single rail work. You CAN use the 741 with the inputs referenced to a "virtual earth" - but its an ancient device with PSU requirements that might be unhelpful in modern designs.
 

MrAl

Joined Jun 17, 2014
6,643
Hi,

Most op amps can be used with a single supply if they are biased properly into linear operation.
There are some though that are designed for somewhat special purposes that require two different supplies. They are usually very high speed but you never know what might come out of the design factory these days.
 
Top