21-Pin Single-Row BergStik — What It Fits
The 77311-824-21LF: The 21-position count is an odd number for a single row — most BergStik headers come in even counts or multiples of two. That means the BOM position count is exact: no depopulating or skipping pins. If your design calls for 21 circuits, this is the header.
3 A Per Contact — What That Means on a 21-Pin Header
With all 21 pins carrying current, the total theoretical capacity is 63 A — but the practical limit is set by the PCB trace width, the number of adjacent pins carrying current simultaneously, and the ambient temperature inside the enclosure.
Through-Hole Solder — Board-Mount Details
The base product number is 77311 — variations in the dash suffix change the post length, plating, or packaging. The -21LF suffix indicates 21 positions with lead-free (RoHS) compliance.