I am searching for dual power supplies to power a single circuit and a common specification I've seen for a few different models state the maximum capacitor load. The circuit I am powering consists of 6 opamps (2 AD8009 and 4 AD8065), along with 7806/7906 to step down +/-12V to +/-6V. How can I determine the capacitor load of this circuit so I can choose a properly rated power supply? I've included an example of a datasheet showing the "Max Capacitor Load" specification table from Mean Well.
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Usually it's any capacitors that are coupled directly to the output of the power supply, in this case it would be only the capacitors on the Vregs and connector (so ~5uf). The voltage regulators act as an impedance buffer so the supply doesn't really 'see' the capacitance of the rest of the circuit.
One of the factors is inrush current and the other is power supply stability. Sometimes even using an inductor or resistor in-between the supply and a capacitiive load will reduce the inrush current to be a non factor.
In this case, with the 4.7Ohm resistor, I don't think I'd factor that in to the power supply rating. Even if you did factor them in, you are still very far under the max rating so connecting them directly, you would be fine.
answered Oct 18, 2022 at 20:31
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\$\begingroup\$ What about the 4 AD8065s? These are to be powered directly from the power supply +/-12V. Would the decoupling capacitors then be added to the total capacitor load? \$\endgroup\$– earlCommented Oct 18, 2022 at 20:37
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\$\begingroup\$ Sorry got distracted, updated \$\endgroup\$– Voltage Spike ♦Commented Oct 18, 2022 at 21:08