Part Number: OPA4197
Hi Team,
I'm planning to use OPA4197 in my analog card. I'm planning to give +12V and -12V as input power supplies. Please provide what will be the supply current to these V+ and V- pins, as only quescient current details are mentioned in the datasheet.
Regards,
Abhishek
Abhishek,
The typical and maximum supply current are defined in the data sheet table across the full supply range and temperature range. This is the quiescent current. Quiescent current means the current consumed by the op amp with no load. The data sheet table shows how the typical current changes with supply voltage and temperature. Both supply voltage and temperature have very little effect on the quiescent current (IQ). Since IQ is defined in the data sheet table across temperature and supply, you don't really need the curves. That is, you can use the maximum values give for any supply or temperature and it will be valid.
Assuming you have a load impedance and feedback resistances the actual current drawn by the op amp will be different than IQ. The supply current can be calculated if you know your output voltage range and load impedance and feedback resistances. Just divide the maximum output voltage by the impedances to get the op amp output current. The supply current is Isup = IQ + ILOAD. In the example below it can be calculated as: Isup = 10V/(20kΩ) + 10V/1k + 1mA = 11.5mA. Note that the 1mA is the typical IQ. Also note that the supply current will increase in the positive supply when the output voltage is positive and in the negative supply when the output voltage is negative. Op amp precision labs section on "power and temperature" cover this topic in detail.
best regards, Art
