Understanding Generic Part Numbers

Generic Part Numbers (GPN)

Generic components are widely used in the assembly of PCBs as they offer an advantage to both the customer and the assembler.

These advantages are explained in the article The power of generic parts by Saar Drimer.

Eurocircuits offers a wide range of generic capacitors, resistors and pin headers (many of which are offered for free), to select one simply click on the appropriate link above and select the required part and add it to your BOM.

Generic parts are defined by their characteristics rather than a manufacturer’s part number (MPN).
However, they still need to have a number (the GPN) that can be added to a BOM in the MPN column. This allows for the part to be automatically identified when uploading the BOM data, in Eurocircuits case this will be performed by the PCBA Visualizer.

Below we will describe how to interpret Eurocircuits generic part numbers.

See also:

The perfect BOM

Generic Resistors

Eurocircuits generic part numbers for resistors is GPRPPPPV and consists of 3 sections as below:

• GPR – fixed prefix for Generic Part Resistor
• PPPP – Package size (example 0402)
• V – the resistance specific, given as an integer, followed by an R for ohms, K for KOhms or M for MOhms

Example 1

This generic part number GPR0402100R describes a resistor with a 0402-package size and a resistance of 100 ohms.

NOTE

• Other parameters such as voltage, power rating and tolerance are listed in the description of the part on our Generic Resistors.

Defining the resistance value

When defining the resistance value (V) the letter (R, K, M) is placed to determine the decimal place.

Example 2

For a 2K ohm resistor should be written as 2K and the full GPN for a 0402-package size would be GPR04022K.

Example 3

For a 2.1Kohm resistor should be written as 2K1 and the full GPN for a 0402-package size would be GPR04022K1.

Defining the Voltage

The voltage is not generally defined in the GPN for a generic resistor, however, if necessary, it can be defined as a suffix as in the example below where the -50 sets the required voltage to 50V.

GPR04022K-50

Power rating

The power rating for the generic resistors supplied by Eurocircuits is determined by the package size as below:

• 0201 – 50mW
• 0402 – 62.5mW
• 0603 – 100mW
• 0805 – 125mW
• 1206 – 250mW

Resistance tolerance

All generic resistors offered by Eurocircuits have a tolerance of ±1%.

Generic capacitors

Eurocircuits generic part numbers for capacitors is GPCPPPPV and consists of 3 sections as below:

• GPC – fixed prefix for Generic Part Capacitor
• PPPP – Package size (example 0402)
• V – the specific capacitance

Example 4

This generic part number GPC0603102 describes a capacitor with a 0603-package size and a capacitance of 1000pf.

Defining the capacitance

The V value of a generic part number for a capacitor is written using common 3-digit code as in the table below.

The V value is highlighted in this example GPC0603102.

To determine the capacitance value simply take the first 2 digits as a number and the 3rd digit indicates the number of zeros after the number (first 2 digits).

Thus the V value of 102 the actual capacitance is 1000pf or 1nf or 0.001µf.

Whereas for a V value of 470 the actual capacitance is 47pf or 0.047nf or 0.000047µf and for a V value of 105 the actual capacitance is 1000000pf or 1000nf or 1µf.

The table below shows the basis for common coding of capacitors:

Common capacitor coding

Defining the Voltage

The required voltage can be added to the generic part number as a suffix as in the example below where the -100 sets the required voltage to 100V.

GPC0603102-100

IMPORTANT

• If no suffix is added for the voltage, then the default voltage selected will be 50V.
• Please check the voltage of the selected generic capacitor as other voltage values may apply. Thes can be 6.3V, 10V, 16V, 25V, 35V and 100V.

See the full list of available Generic Capacitors from Eurocircuits.

Defining the application class

The suffix of the GPN can be extended to include the application class X5R or X7R which determine the operating temperature range of a ceramic capacitor.

The X7R code defines the operating temperature range as -55°C to +125°C, operating outside of this temperature range the capacitance characteristics may change by a maximum of ±15%.

Whilst the X5R code defines the operating temperature range as -55°C to 85°C, operating outside of this temperature range the capacitance characteristics may change by a maximum of ±15%.

To define either of these values as part of the generic part number simply add either -X5R or -X7R as a suffix, see the examples below:

• GPC0603102-100-X5R (with voltage suffix)
• GPC0603102-X5R (without voltage suffix)
• GPC0603102-100-X7R (with voltage suffix)
• GPC0603102-X7R (without voltage suffix)

Example of capacitors with application class

Generic Pin Headers

As there is no commonly used way to identify generic pin headers and thus Eurocircuits devised their using a prefix of GPH (Generic Pin Header).

Currently, Eurocircuits offers 4 types of generic pin headers as below:

• Type A – straight pins (GPHA)
• Type B – right angle pins (GPHB)
• Type C – WR-PHD WERI Straight Pins (GPHC)
• Type D – WR-PHD Straight Pins (GPHD)

Eurocircuits generic part numbers for pin headers is GPH(x)-PPPP and consists of 3 sections as below:

• GPH – fixed prefix for Generic Part (Pin) Headers
• (x) – Pin header type (A,B,C or D)
• PPPP – Pin header configuration code (# pins and rows)

Example 5

This generic part number GPHA-2X03 describes a type A pin header with 2 rows of 3 pins (6 pins in total).

Further details can be found in our Generic Pin Header list.