| Electronics > Beginners |
| quiescent current of opamp |
| (1/1) |
| Jwillis:
On the OPA445 the quiescent current is typically ±4.2 mA . That means that the positive and negative will draw ±4.2mA with no load. How do I calculate the current at the supply pins under full load? Or am I over thinking this? https://www.ti.com/lit/ds/symlink/opa445.pdf |
| ledtester:
Starting with I_Q, just add the output current to the V+ current (if the output is sourcing current) or the V- current (if the output is sinking current). So the max current through either the V+ or V- supply pin is i_Q + your max output current. See also: https://electronics.stackexchange.com/a/31032/95488 |
| Jwillis:
Wow! That easy? I thought it would be more complex. Just wanted to make sure a 1 amp -15V regulator at the negative side would be enough without a pass transistor. |
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