Why the opamp's output stage is designed to drive low resistive/large capacitive load

[reziger]

Hi, Why the output stage of op-amp is designed to drive low resistive load and large capacitive load usually?

 

[hmsheng]

output stage

If an output stage can drive low resistive load or large capacitive load it surely can drive high resistive load and low capacitive load beacause it has large drive ability. Conversely, it's not true.

 

[reziger]

output stage

thanks, but i still don't understand that if an op-amp can drive low resistive load, why could to drive high resistive load? Is because voltage of ouput stable while driving low resistive load that means output current is large enough to be sourced and sunk?
What about for driving capacitive loads?

 

[rajanarender_suram]

output stage

if an opamp can drive low resistive loads means it can support large drive currents. The higher resistances requires lower currents for same output voltages.

u can think similarly for capacitances

 

[hmsheng]

output stage

If we say one opamp can't drive a load, we means that the gain of the opamp decreases to an undesired level when driving the load at some frequency. As was known that the load impedance will affect the gain of the opamp. Generally, high load impedance gives high opamp gain. Large capacitive load and small resistive load are low impedance load. So if the opamp can drive a high impedance load it may not can drive a low impedance load.

 

[abhityagi85]

output stage

h
opamp is used to drive small resistive load coz the input impedance of many stages is low. high capacitive load means a lot of device are connected to its output which it should be able to drive. simple

 

[reziger]

output stage

Thank you
I understand now