# Opamp power consumption

Attached simulation of op-amp .

Q1) In Op-amp ckt 1 has power supply of 20V and In Op-amp ckt 2 has power supply of 15V (rest everything is same). How current consumption is more in 20V rather than 15V supply ( see image opamp ckt 1 and opamp ckt 2 , current consumption is 1.33mA and 1mA respectfully). If everything is same then current consumed should be low or high.

Q2) How to Calculate total power consumption in opamp ckt 3. ( as per simulation result, see image opamp ckt 3)

Q3) In opamp ckt 3 , Input power consumption is 15 V*1m A=15 mW , and output power given is 9.59 V*9.59 mA= 91.9 mW, how output can divilerd more power than input consumed.

• You're assuming that the model for the opamp is a realistic model. Obviously it is not ! This model obviously does not take the current supplied from the output into account. Maybe you should try a more realistic model for the opamp, perhaps a transistor level model. May 12, 2016 at 9:23
• Read this for a really good explanation of opamp models: linear.com/docs/4139 May 12, 2016 at 11:40