Hi,
I'm trying to avoid any bias tunning with a LM358 throughout a Virtual Ground in a single Power Supply. So the idea is to supply +10v and split by 2 to have +5V and -5v supplying the Op Amp LM358 with the help of the second Op Amp in the same Chip.
The data is:
Power Supply:
Vcc+ = +10v;
Virtual Ground = +5v;
Vcc- = 0v.
Function generator:
Amplitude = 0.30v;
Frequency = 10kHz.
In the Proteus Simulator (A try the LTSpice first but it hasn't the LM358 Op Amp!), where U1:B serves to create the Virtual Ground and the U1:A does the amplification. On the simulator everything looks nice like this:
However, in the real world this is the result after trying with two different LM358 chips:
Is this due to some sort of polarity transition on the chip, does this means that I absolutely need a cap in the output. This is odd because with the traditional inverting amplifier I haven't this kind of output shifting!
In the breadboard I always used the Virtual Ground as ground when connecting the oscilloscope and function generator. I also used a portable multimeter to see any changes on the +5v of the Virtual Ground with no changes at all seen!
Any ideas?