LED Driver Ripple Current and Flicker Index Calculator

ANALife Services AuthorityNational Calculator Authority›LED Driver Ripple Current and Flicker Index Calculator

.calc-container { max-width: 640px; margin: 2rem 0; padding: 1.5rem; background: #fff; border: 1px solid #ddd; border-radius: 8px; box-shadow: 0 1px 3px rgba(0,0,0,0.06); font-family: system-ui, -apple-system, sans-serif; } .calc-container h3 { font-family: Georgia, serif; font-size: 1.15rem; color: #1a1a1a; margin-bottom: 1rem; padding-bottom: 0.5rem; border-bottom: 2px solid var(--ac, #3d5a80); } .calc-row { display: flex; align-items: center; gap: 0.75rem; margin-bottom: 0.75rem; flex-wrap: wrap; } .calc-row label { min-width: 160px; font-size: 0.9rem; color: #333; font-weight: 500; } .calc-row input[type="number"], .calc-row select { flex: 1; min-width: 120px; max-width: 200px; padding: 0.5rem 0.6rem; border: 1px solid #ccc; border-radius: 4px; font-size: 0.9rem; font-family: system-ui, sans-serif; color: #1a1a1a; background: #fafaf8; } .calc-row input:focus, .calc-row select:focus { outline: none; border-color: var(--ac, #3d5a80); box-shadow: 0 0 0 2px rgba(26,74,138,0.12); } .calc-row .unit { font-size: 0.82rem; color: #888; min-width: 30px; } .calc-btn { display: inline-block; margin-top: 0.5rem; padding: 0.55rem 1.5rem; background: var(--ac, #3d5a80); color: #fff; border: none; border-radius: 4px; font-size: 0.9rem; font-weight: 600; cursor: pointer; font-family: system-ui, sans-serif; } .calc-btn:hover { opacity: 0.9; } .calc-result { margin-top: 1.25rem; padding: 1rem 1.25rem; background: #f0f6fc; border-left: 3px solid var(--ac, #3d5a80); border-radius: 0 6px 6px 0; display: none; } .calc-result.visible { display: block; } .calc-result-label { font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.06em; color: #666; margin-bottom: 0.25rem; } .calc-result-value { font-size: 1.6rem; font-weight: 700; color: var(--ac, #3d5a80); } .calc-result-detail { font-size: 0.85rem; color: #555; margin-top: 0.5rem; line-height: 1.5; } .calc-note { margin-top: 1rem; font-size: 0.8rem; color: #888; font-style: italic; } .calc-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0.75rem; margin-top: 0.75rem; } .calc-grid-item { padding: 0.6rem 0.8rem; background: #f8f9fa; border-radius: 4px; border: 1px solid #eee; } .calc-grid-item .label { font-size: 0.75rem; color: #888; text-transform: uppercase; letter-spacing: 0.04em; } .calc-grid-item .value { font-size: 1.1rem; font-weight: 600; color: #1a1a1a; } @media (max-width: 720px) { .calc-row { flex-direction: column; align-items: flex-start; gap: 0.3rem; } .calc-row label { min-width: auto; } .calc-row input[type="number"], .calc-row select { max-width: 100%; width: 100%; } .calc-grid { grid-template-columns: 1fr; } } .calc-chart { margin: 1rem 0; text-align: center; } .calc-chart svg { max-width: 100%; height: auto; } .calc-chart-legend { display: flex; flex-wrap: wrap; justify-content: center; gap: 0.6rem 1.2rem; margin-top: 0.6rem; font-size: 0.8rem; color: #555; } .calc-chart-legend span { display: inline-flex; align-items: center; gap: 0.3rem; } .calc-chart-legend i { display: inline-block; width: 10px; height: 10px; border-radius: 2px; font-style: normal; } .calc-related { max-width: 640px; margin: 2rem 0 1rem; padding: 1.25rem 1.5rem; background: #f8f9fa; border: 1px solid #e8e8e8; border-radius: 8px; } .calc-related h3 { font-family: Georgia, serif; font-size: 1rem; color: #1a1a1a; margin: 0 0 0.75rem; padding-bottom: 0.4rem; border-bottom: 2px solid var(--ac, #3d5a80); } .calc-related-list { list-style: none; padding: 0; margin: 0 0 0.75rem; display: grid; grid-template-columns: 1fr 1fr; gap: 0.4rem 1.5rem; } .calc-related-list li a { font-size: 0.88rem; color: var(--ac, #3d5a80); text-decoration: none; } .calc-related-list li a:hover { text-decoration: underline; } .calc-browse-all { margin: 0.5rem 0 0; font-size: 0.9rem; font-weight: 600; } .calc-browse-all a { color: var(--ac, #3d5a80); text-decoration: none; } .calc-browse-all a:hover { text-decoration: underline; } @media (max-width: 720px) { .calc-related-list { grid-template-columns: 1fr; } }

LED Driver Ripple Current and Flicker Index Calculator

Calculate the ripple current percentage and flicker index of an LED driver from its peak, minimum, and average output current waveform values. These metrics are critical for evaluating LED flicker performance and driver quality.

Peak Current Ipeak (mA)

Minimum Current Imin (mA)

Average Current Iavg (mA) (optional — computed if blank)

Waveform Shape (for area calculation)

Sinusoidal / Smooth Triangular Square / Flat-top

Calculate

### Results

Ripple Current % Flicker Index Flicker Percent (%) Average Current Used (mA) Flicker Risk Assessment

function ledCalc() { var errEl = document.getElementById('led-error'); var resEl = document.getElementById('led-result'); errEl.style.display = 'none'; resEl.style.display = 'none';

var iPeak = parseFloat(document.getElementById('led-i-peak').value); var iMin = parseFloat(document.getElementById('led-i-min').value); var iAvgInput = document.getElementById('led-i-avg').value.trim(); var waveform = document.getElementById('led-waveform').value;

// --- Validation --- if (isNaN(iPeak) || isNaN(iMin)) { errEl.textContent = 'Error: Peak and Minimum current values are required.'; errEl.style.display = 'block'; return; } if (iPeak iPeak) { errEl.textContent = 'Error: Minimum current cannot exceed peak current.'; errEl.style.display = 'block'; return; } if (iPeak === 0) { errEl.textContent = 'Error: Peak current must be greater than zero.'; errEl.style.display = 'block'; return; }

// --- Average current --- var iAvg; var avgSource; if (iAvgInput !== '') { iAvg = parseFloat(iAvgInput); if (isNaN(iAvg) || iAvg iPeak) { errEl.textContent = 'Error: Average current cannot exceed peak current.'; errEl.style.display = 'block'; return; } if (iAvg 90 Hz; verify application'; riskColor = '#f39c12'; } else if (flickerPercent

#### Formulas Used

Ripple Current Percentage (per ANSI/IES TM-16 & IEEE PAR1789):

Ripple% = [ (I_peak − I_min) / (I_peak + I_min) ] × 100

Flicker Percent (IEEE PAR1789-2015 — identical to Ripple% for sinusoidal waveforms):

Flicker% = [ (I_peak − I_min) / (I_peak + I_min) ] × 100

Flicker Index (IES TM-16-2012 closed-form approximation):

Flicker Index = (I_peak − I_avg) / (2 × I_avg)

Where I_avg is estimated as: • Sinusoidal / Triangular waveform: I_avg = (I_peak + I_min) / 2 • Square wave (full conduction): I_avg = I_peak → FI ≈ 0 • User-provided I_avg: used directly

Exact Flicker Index (from waveform area — requires full waveform data):

Flicker Index = (Area above average level) / (Total area under one cycle)

#### Assumptions & References

More Calculators

Read Next

Study Time Planner Authority Network America › Life Services Authority › National Calculator Authority .calc-container { max-width: 640px;...

References