ESR Chart for Capacitors: Reference Values by Type, Voltage, and Frequency

Equivalent Series Resistance (ESR) is the internal ohmic resistance of a capacitor that dictates power loss, internal heating, and output ripple voltage. If you need the direct answer: a standard 100µF 16V aluminum electrolytic capacitor typically exhibits an ESR of 0.80Ω at 120Hz, dropping to roughly 0.35Ω at 100kHz. A 10µF 50V X7R ceramic capacitor (MLCC) will measure under 0.02Ω at 100kHz. When a 2A switching ripple current hits a degraded electrolytic cap with an ESR of 1.0Ω, it generates 2V of peak-to-peak ripple and 4W of internal heat—enough to boil the electrolyte and destroy the component.

The reference data below provides baseline ESR values for the most common through-hole and surface-mount capacitors used in power supplies, audio circuits, and embedded systems. Bookmark the quick-jump links below for your most frequent bench lookups.

The Master ESR Chart for Capacitors (Reference Table)

How to read this table: The ESR @ 120Hz column applies to linear power supply rectifier filtering and audio coupling circuits. The ESR @ 100kHz column applies to Switch-Mode Power Supplies (SMPS), DC-DC buck/boost converters, and high-frequency digital bypassing. Values represent typical maximums at +20°C ambient for new components, sourced from manufacturer datasheets and standardized under IEC 60384 (fixed electrolytics) and EIA-198 (ceramics).

Quick-Jump Bench References:
➔ Jump to Troubleshooting Thresholds (When to throw a cap away)
➔ Jump to Temperature & Frequency Derating Multipliers

Applying the Chart: Columns, Derating, and Installation Context

A common mistake on the workbench is measuring a capacitor with a cheap ESR meter (which typically injects a 100kHz test signal) and comparing it to the 120Hz column on a vintage schematic or standard datasheet. You must match the measurement frequency to the circuit's operating frequency.

Which Column Applies to Your Installation?

• Use the 120Hz column if the capacitor is sitting on the output of a 50/60Hz mains transformer bridge rectifier, or if it is an audio coupling capacitor handling sub-20kHz signals. The ripple frequency here is 120Hz (full-wave rectified 60Hz).
• Use the 100kHz column if the capacitor is on the output of a switching regulator (buck, boost, flyback) or serving as a high-frequency decoupling cap near a microcontroller's VCC pin. Switching nodes operate between 100kHz and 2MHz.

How Derating Modifies the Base Value

The values in the master chart assume a +20°C ambient temperature. In practice, ESR is highly temperature-dependent, particularly for wet aluminum electrolytics. As temperature drops, the electrolyte's viscosity increases, driving ESR up. As temperature rises, ESR drops until you hit the component's thermal limits.

Example: If your SMPS operates in a -10°C outdoor enclosure, a 100µF 16V Low-ESR aluminum cap with a base chart value of 0.08Ω at 100kHz will actually exhibit an ESR of roughly 0.16Ω (0.08Ω × 2.0 multiplier). You must recalculate your ripple voltage (V_ripple = I_ripple × ESR) using this derated value to ensure your logic rails stay within tolerance.

What the ESR Chart Cannot Tell You (Edge Cases and Limits)

Reference charts assume new, properly installed components. They fail to account for three critical real-world variables that dictate circuit reliability.

1. Electrolyte Dry-Out and Aging

The chart lists the initial ESR. Aluminum electrolytic capacitors slowly lose their liquid electrolyte through the rubber end seal over time, a process accelerated by heat. According to Texas Instruments Application Report (SLYT271), an electrolytic capacitor operating continuously at its maximum rated temperature (e.g., 105°C) will reach its end-of-life when its ESR increases to roughly 200% to 300% of its initial chart value. A chart cannot tell you the ESR of a 10-year-old motherboard capacitor; you must measure it in-circuit or out-of-circuit with an LCR meter.

2. PCB Trace Resistance and Via Inductance

If you are designing a high-current DC-DC converter, the ESR of the physical capacitor is only half the story. The copper traces and vias connecting the capacitor to the IC add series resistance and Equivalent Series Inductance (ESL). A 10µF X7R ceramic capacitor might have an intrinsic ESR of 0.015Ω, but if it is routed through two 0.3mm vias and a thin trace, the total effective impedance at 1MHz will be significantly higher. Always place high-frequency bypass capacitors as physically close to the IC VCC/GND pins as possible to minimize PCB parasitics.

3. Dielectric Absorption and Leakage Current

ESR measures purely resistive AC losses. It does not account for DC leakage current (which drains batteries in portable devices) or dielectric absorption (which causes capacitors to 'rebound' with voltage after being discharged, a critical flaw in sample-and-hold circuits). For precision analog work, consult the specific manufacturer datasheet for Dissipation Factor (DF) and leakage specs, rather than relying solely on an ESR summary chart.

Quick-Jump Troubleshooting: When to Replace Based on Measured ESR

When debugging a dead power supply or a glitching embedded board, you need fast pass/fail thresholds. While the Analog Devices Technical Dialogue emphasizes that ESR impacts control loop stability in LDOs and switching regulators, on the bench, you are usually just looking for thermal degradation.

Specific Pass/Fail Thresholds for Common Bench Repairs

• ATX Power Supply 12V Rail (1000µF / 16V Low-ESR): Chart baseline is ~0.04Ω. If your meter reads > 0.15Ω, the cap is failing. This is the most common cause of 'PC randomly reboots under load' symptoms.
• LCD Monitor Power Board (470µF / 25V Std): Chart baseline is ~0.15Ω at 100kHz. If your meter reads > 0.80Ω, bin it. These caps sit next to hot switching MOSFETs and bake over time.
• Arduino / ESP32 3.3V Rail Bypass (10µF / 16V Ceramic): Chart baseline is < 0.05Ω. If your LCR meter reads > 0.20Ω, the component has likely suffered a micro-crack from board flexing or thermal shock during hand soldering. Replace it.

Always discharge capacitors safely before measuring ESR in-circuit, and remember that parallel components (like a 0.1µF ceramic bypass sitting next to a 100µF electrolytic) will skew your in-circuit ESR reading. If a measurement looks suspiciously low or reads as a dead short, desolder one leg of the capacitor to isolate it from the PCB network.