CDE Cornell Dubilier • 1605 East Rodney French Blvd • New Bedford, MA 02744 • Phone: (508)996-8561 • Fax: (508)996-3830

PCB Mount Power Film Capacitors

Expected Lifetime Predictions

Determine ESR at Operating Frequency

Use the 10 kHz ESR from the ratings tables.

For operation below 10 kHz, the ESR will need to be adjusted using the following

equation: ESR - 31.83/(10C) + 31.83/(fC).

Determine Thermal Resistance at Operating Frequency and Air Flow

Compute Θ = Θ

multiply Θ

0.66

Determine Expected Lifetime

Look up Expected Lifetime on the graph using V

2

(ESR/1000) Θ

The maximum allowed temperature rise is 40 °C and the maximum allowed core

temperature is 95 °C.

Capacitance:

Equivalent Series Resistance:

Frequency:

Ripple Current:

Ambient Temperature:

Core Temperature:

Total Thermal Resistance:

Thermal Resistance case-to-ambient:

Thermal Resistance core-to-case:

Airflow Speed:

Applied Voltage:

Rated Voltage:

C (µF)

ESR (mΩ)

f (kHz)

I (A

T

T

Θ (°C/W)

Θ

Θ

v (m/s)

V

V

0.8

0.9

1

1.1

1.2

1.3

1.4

1.5

1.6

1.7

100

1000

10000

100000

1000000

Expected Lifetime (h)

Expected Lifetime vs Core Temperature and Applied DC Voltage

50ºC

60ºC

70ºC

85ºC

Type BLC Polypropylene Board Mount DC Link Capacitors