TL7660: Output Current

Hello Shuji,

Thanks for reaching out to us via e2e.

1) Can the TL7660 pass an output current (Iout) of 100mA?
In theory, yes. But please keep in mind that the output of the TL7660 behaves like a power source with a much higher output impedance as for example a lab supply.
Therefore, when you draw 100mA, the output voltage will drop to around 0.6V.

2) Does RSW fluctuate depending on the specification conditions?
Please tell me Min and Max of RSW.

RSW is just used to show the principle.
ROUT is more important, It depends on input voltage, frequency and temperature (see diagrams in the datasheet.
As a simplification you can use the table below and add the influence of the ESR of the capacitor:
RO ≈ ROUT from the table below + 5 * ESR_C

3) I have a question about the graph below.
Am I correct in understanding that when the IL current increases, the output voltage increases proportionally?
The diagram shows negative voltages.
The magnitude of the voltage actually decreases with higher load current. (From -5V decreasing to only 3.25V)

4) I have a question about the graph below.
Since IL=25mA when Icc=50mA, I think the efficiency η=50%, but the graph shows 90%.
Is the efficiency stated in the graph the input/output power efficiency? or efficiency by another calculation?
This graph is meant for the voltage doubler use case.
The inupt power equals the output power: Uin * Iin = Uout * Iout.
Output voltage = 2 * input voltage. But therefore, output current = 1/2 * input current

Best regards
Harry