A typical low-ESR 1000µF 16V aluminum electrolytic capacitor has an Equivalent Series Resistance (ESR) between 15mΩ and 25mΩ when measured at 100kHz and +20°C. Standard-grade capacitors of the same value typically range from 100mΩ to 200mΩ. If you are troubleshooting a switching power supply or designing an output filter, knowing the exact ESR baseline is the difference between a stable rail and a blown MOSFET.
This reference provides the baseline ESR values for radial aluminum electrolytic capacitors, the derating multipliers you need for real-world temperatures, and the physical limitations of these charts.
The Master ESR Capacitance Chart (Radial Aluminum Electrolytic)
The following table aggregates baseline ESR specifications aligned with IEC 60384-4 testing standards for fixed aluminum electrolytic capacitors. The values represent maximum guaranteed ESR at +20°C and 100kHz, reflecting data from industry-standard low-ESR series like the Panasonic FR/FM, Nichicon PW, and Rubycon ZL lines.
Bookmark Quick-Jumps: 470µF | 1000µF | 2200µF | 4700µF
| Capacitance (µF) | Voltage Rating (V) | Standard ESR (mΩ) | Low-ESR (mΩ) | Ultra-Low ESR (mΩ) |
|---|---|---|---|---|
| 10 | 16 / 25 | 1200 - 1500 | 400 - 600 | 150 - 250 |
| 22 | 16 / 25 | 800 - 1000 | 250 - 400 | 90 - 150 |
| 47 | 16 / 25 | 500 - 700 | 150 - 250 | 50 - 80 |
| 100 | 16 / 25 | 300 - 450 | 80 - 120 | 30 - 45 |
| 220 | 16 / 25 | 180 - 250 | 45 - 70 | 18 - 28 |
| 470 | 16 / 25 | 100 - 150 | 25 - 40 | 12 - 18 |
| 1000 | 16 / 25 | 60 - 90 | 15 - 25 | 8 - 12 |
| 2200 | 16 / 25 | 35 - 55 | 10 - 18 | 5 - 9 |
| 3300 | 16 / 25 | 25 - 40 | 8 - 14 | 4 - 7 |
| 4700 | 16 / 25 | 18 - 30 | 6 - 12 | 3 - 6 |
Applying Derating Factors to Your Base ESR
The chart above assumes a bench-top environment of +20°C and a test frequency of 100kHz. In practice, your capacitor will operate at different temperatures and frequencies. To find the real-world ESR, you must apply derating multipliers to the base value. This is how derating rows modify the base value:
Temperature Derating
Electrolytic fluid viscosity increases as temperature drops, causing ESR to spike. If your base ESR is 20mΩ at +20°C, you must multiply that value based on the operating environment:
- +85°C to +105°C: Multiply by 0.7 to 0.8 (ESR drops as the electrolyte thins).
- 0°C: Multiply by 1.5 to 2.0.
- -10°C: Multiply by 2.5 to 3.5.
- -25°C: Multiply by 5.0 to 8.0 (Standard electrolytics become nearly useless here; use polymer or specialized low-temp caps).
Frequency Derating
ESR is highly frequency-dependent. While SMPS designs operate at 100kHz+, line-frequency filters operate at 120Hz (the ripple frequency of a full-wave rectified 60Hz AC line). According to fundamental capacitor impedance models, the dielectric and electrolyte resistance dominate at lower frequencies.
- 100kHz: Multiplier 1.0 (Base value).
- 10kHz: Multiplier 1.2 to 1.5.
- 1kHz: Multiplier 1.8 to 2.5.
- 120Hz: Multiplier 3.0 to 6.0 (A 20mΩ low-ESR cap at 100kHz may exhibit 80mΩ+ at 120Hz).
What This Chart Cannot Tell You (And How to Compensate)
Reference charts provide baseline manufacturing specs, but they are blind to operational physics and circuit topology. Relying solely on the datasheet ESR will lead to design failures if you ignore these three blind spots:
2. In-Circuit Measurement Interference: When troubleshooting a dead motherboard or power supply with a handheld ESR meter, you are measuring the parallel combination of the target electrolytic cap and any parallel ceramic decoupling capacitors. Because ceramics have near-zero ESR (often <5mΩ), your meter will read the ceramic's ESR, masking a completely dried-out electrolytic cap. Compensation: Always lift one leg of the electrolytic capacitor out of the PCB to measure it in isolation, or desolder it entirely.
3. Ripple Current Heating: The chart gives you a static resistance. It does not tell you how much the capacitor will self-heat when subjected to 3A of ripple current. High ESR combined with high ripple causes internal I²R heating, which accelerates dry-out. Compensation: Cross-reference the ESR chart with the manufacturer's 'Max Ripple Current' rating. If your calculated ripple exceeds 80% of the max rating, parallel two smaller caps to halve the ESR and double the thermal mass.
Frequently Asked Questions (FAQ)
What is a good ESR value for a 1000uF 16V capacitor?
For a standard general-purpose replacement, anything under 90mΩ at 100kHz is acceptable. However, if this capacitor is on the output rail of a switching power supply (like a PC motherboard or LED driver), you must use a low-ESR variant. A 'good' reading for a low-ESR 1000µF 16V cap (like a Panasonic EEUFR1C102) is between 15mΩ and 25mΩ. If your ESR meter reads above 40mΩ on a low-ESR cap, it has degraded and should be replaced.
Can I use a standard ESR capacitor in a switching power supply?
No. Standard ESR capacitors are designed for 50/60Hz line filtering and cannot dissipate the heat generated by high-frequency (50kHz - 200kHz) switching ripple. If you place a standard 1000µF cap in an SMPS output, its higher ESR (e.g., 80mΩ) will cause excessive I²R heating. The internal temperature will rapidly exceed the capacitor's rated maximum, boiling the electrolyte and causing the vent to pop within hours or days. Always use Low-ESR or Ultra-Low ESR series for SMPS applications.
Why does my ESR meter read zero or 'short' on a small ceramic capacitor?
Handheld ESR meters typically inject a 100kHz AC test signal. Multi-layer ceramic capacitors (MLCCs) in the 0.1µF to 10µF range have exceptionally low impedance at 100kHz, often dropping below 5mΩ. Most standard ESR meters cannot accurately resolve resistances below 10mΩ and will display '0.00' or indicate a short circuit. This is normal. To measure ceramic capacitor health, you must use an LCR meter capable of measuring at 1MHz, or rely on capacitance value and physical inspection for cracking.
How does temperature affect the ESR of an electrolytic capacitor?
Temperature has an inverse relationship with ESR in aluminum electrolytics. As temperature rises, the electrolyte becomes less viscous, improving ion mobility and lowering ESR (up to the capacitor's maximum rated temperature, usually 85°C or 105°C). Conversely, as temperature drops below +20°C, the electrolyte thickens, and ESR spikes dramatically. At -20°C, a capacitor's ESR can be 5 to 10 times higher than its room-temperature specification, which is why outdoor or automotive electronics require specialized low-temperature electrolytic or solid polymer capacitors.
For deeper analysis on capacitor failure modes and thermal modeling, refer to the Cornell Dubilier technical paper library, which provides extensive application notes on ripple current calculations and lifecycle estimations.
