Polystyrene Film Capacitors

Polystyrene film capacitors are highly regarded by the audiophile community for their low distortion factor, which makes these capacitors really shine in audio applications. Polystyrene capacitors are often used as replacements for ceramic and mica capacitors in audio circuits. However this type of capacitor is not limited to only audio applications, it’s perfect for any application that requires a through hole high tolerance capacitor. Polystyrene as a dielectric has many positive properties which include a low dielectric absorption, low distortion, low leakage, high insulation, and excellent temperature stability. Polystyrene film capacitors are available in both radial and axial leads. However the axial lead style is much more popular than the radial lead style. Polystyrene capacitors are a excellent choice for applications like point to point wiring or PCB(Printed Circuit Board) applications.

Identifying the voltage of a polystyrene film capacitor is very simple. All you have to do is just take a look at the color of the band on the capacitor. Follow the color code shown in the images below:

33VDC = Blue Band

63VDC = Yellow Band

160VDC = Red Band

630VDC = Black Band

Note: not all polystyrene film capacitors are color coded, some of them just have plastic sleeves with printed values on their cases.

1. Dielectric

• PS - Polystyrene

2. Case Style

• 1 - Round Body
• 2 - Flat Body

3. Size Class

• 1 - Standard Size
• 2 - Miniature
• 3 - Smallest Size
• X - Custom Size

4. Capacitance
Capacitance is expressed in microfarads(MFD), use as many digits as required.

5. Voltage Rating
The voltage rating is expressed in VDC.

6. Tolerance
Tolerance is expressed in a percentage.

1. Dielectric

• SX - Polystyrene

2. Capacitance Tolerance

• SXK, SXL, SXM - ±2.5%
• SX - ±5.0%

3. Capacitance
Capacitance is expressed in picofarads(pF), the first digit denotes the number of zeros after the decimal point. The follwing digits are the actual value.
Example:

• 139 = 39,000pF
• 139 = 0.039μF

1. Dielectric

• 704C1 - Polystyrene

2. Case Size
Click here to view 704C1 case sizes

3. Capacitance
First two digits represent significant figures and the last digit indicates number of zeros to follow.
Example:

• 100 = 10pF
• 101 = 100pF
• 102 = 1000pF
• 103 = .01μF

4. Tolerance

• J = ±5%
• G = ±2%
• F = ±1%

5. Voltage
Voltage at 85°C

• 630 = 63V
• 161 = 160V
• 251 = 250V
• 631 = 630V

6. Packaging

• A = Standard
• T = Tape and Reel

7. Lead Type

• X = Axial Lead