TLV8544: Block Diagram

Hi Ron

 Is there detail information like the below picture?

The (not very helpful) functional block diagram for most CMOS opamps is this:

Hi Harry,

the functional block diagrams in the latest datasheets are usually highly simplified and not very helpful. This was highly different many decades ago when the manufacturers hadn't to struggle with product piracy yet.

What do you hope to see in the functional block diagram?

Kai

Hi Kai

Understand.

Customer wanna know the output stage, they found the output will impact the power supply and input stage,  if there are any routes internal will cause this? like a protection diode or others.

Hey Harry, 

There are CMRR and PSRR curves available in the datasheet (Figure 10 and 11). 

There are also available trainings for both on ti.com: 

PSRR training

CMRR training

Please let us know if you need a schematic review. 

All the best,
Carolina 

Harry,

It is common practice to connect sources to back gates for FETs. That means VOUT voltage that is outside the supply power rails will pass current (diode action) from drain to back gate (which is shorted to source).  Output voltage usually gets back to input though the external passive resistors in the feedback network (the resistor(s) you put there)

Hi Clemens

As the picture you showed.

if there is a overload add in Vo,  will the power supply voltage V+ be pulled down through the upper Mos?

Unless the datasheet says otherwise, you have to assume that the body diode of the MOSFET allows current to flow from the output into V+.

Hi Harry,

please explain how and why an overload is added at Vo in your application.

If the output voltage can exceed the supply voltage you should add a Schottky diode clamp from the output pin to the supply voltage pin and a current limiting resistor in series to the output of OPAmp to limit the current through the Schottky diode.

Keep in mind that now a reverse current can flow into the supply voltage line. So either your supply voltage can absorb this reverse current or you should stop any reverse current by adding a diode in series to the supply voltage line.

Kai