Hello,
We have a design where the minimum consumption on both amplifier power supplies (+/-12V) is a key design driver.
- What is the minimum quiescent current per amplifier to be considered ? At room temperature and in the whole temperature range ?
- How is split the quiescent current in both operational amplifier power supplies ?
Best regard,
Hello Frederic,
A minimum operating current limit is not specified for the OPA2140 as is the case for most op amps and TI makes no datasheet assurances about what it will be for the OPA2140.
Figure 13 in the datasheet, Quiescent Current vs Temperature, shows the "typical" per op amp section quiescent current over temperature. Using the graph you can see that at the minimum temperature of -40 C, the quiescent current is minimum at about 1.4 mA per op amp. When you include the normal variations that occur across manufacturing lots the graph line in Figure 13 can shift up or down. Since you are concerned about minimum current that would be a shift downward for the entire line. Since TI doesn't make any datasheet assurances about minimum current all we can provide is an estimate of that minimum current. A practical estimate is that it might be about 25 % lower than that depicted in the Figure 13 graph.
The current normally splits about 50-50 between the two OPA2140 op amps, and most other dual op amps. That is because the layout of one op amp is almost always the flip of the other so all the active circuits have the same dimensions resulting a close match.
Regards, Thomas
Precision Amplifiers Applications Engineering
