Power Electronics
Model class: Standard approximation
Charge-pump voltage and ripple estimator
Estimate ideal no-load charge-pump output voltage and a simplified I/(fC) ripple term.
Interactive engine
Start with the stated conditions.
Values stay in this browser. Choose a representative scenario, then calculate deliberately.
Example ready
Calculate to inspect the result.
The result will identify the direct answer, assumptions, and any warning that changes the next decision.
Assumptions to check
- The entered charge-pump-estimator values represent the stated operating condition.
- This standard approximation is evaluated in the declared lumped or first-pass model.
- A charge-pump-estimator calculation is not a component qualification or safety approval.
What this charge-pump-estimator calculation establishes
Estimate ideal no-load charge-pump output voltage and a simplified I/(fC) ripple term. The useful result is the stated electrical quantity and the decision it supports, not an unstated claim about a finished product. This engine keeps the governing relationship visible so an input, unit, condition, or model boundary can be reviewed before a value becomes a component or layout choice.
No-load output is input voltage times the ideal topology multiplier; the ripple term uses load current divided by switching frequency times capacitance. Treat the number as a first-pass result for the declared operating point. When a source, load, temperature, frequency, waveform, component tolerance, or measurement condition changes, repeat the calculation at the relevant corner rather than assuming the nominal answer persists.
Worked decision context
An ideal 2x pump from 5 V gives 10 V no-load; 10 mA at 100 kHz with 10 µF gives a 10 mV I/(fC) ripple term before topology factors. That example verifies the equation and illustrates the scale of the result, but it does not select a part by itself. Compare the result with available values, ratings, tolerance bands, and the receiving circuit or physical environment before implementation.
Use the primary output to identify the binding constraint. If it leaves little margin, document which input dominates and use selected-part data, a higher-fidelity model, simulation, or measurement. This is especially important when a small numerical difference changes a thermal, timing, noise, or reliability decision.
Limits and validation handoff
Real output droop also depends on switch resistance, flying-capacitor ESR, and topology-specific charge-transfer factors beyond this simplified ripple term. The calculation does not silently include omitted parasitics, installation conditions, manufacturing variation, or product policy. Those conditions can be decisive even when the arithmetic is exact for the selected model.
Record inputs, units, model assumptions, and the intended decision with the result. Verify the leading risk against the selected component data sheet and a representative measurement when the circuit has consequential energy, high voltage, safety, compliance, or reliability requirements.
Common mistakes
- Treating the charge-pump-estimator result as a guaranteed operating limit rather than a first-pass standard approximation estimate.
- Mixing a data-sheet value measured under one condition with this charge-pump-estimator calculation performed at another.
- Selecting a component before checking the boundary this calculation names: real output droop also depends on switch resistance, flying-capacitor ESR, and topology-specific charge-transfer factors beyond this simplified ripple term.
Model limit and handoff
Keep the entered charge-pump-estimator conditions with the calculation, then validate the binding limit using the selected component, physical implementation, and representative operating corner.
FAQs
Is this charge-pump-estimator result sufficient to approve a design?
No. It applies standard approximation reasoning to the entered charge-pump-estimator values and names the checks that still need selected-part data, a higher-fidelity model, or measurement. Real output droop also depends on switch resistance, flying-capacitor ESR, and topology-specific charge-transfer factors beyond this simplified ripple term.
What does this charge-pump-estimator calculator assume that could make the result wrong?
No-load output is input voltage times the ideal topology multiplier; the ripple term uses load current divided by switching frequency times capacitance. If the entered values do not match the real operating condition, the result no longer describes the actual circuit.
Where should this charge-pump-estimator result go next?
Compare this charge-pump-estimator result with Power converter design workflow, then use the stated next decision below the calculator to move from this first-pass number toward an implementation.