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TL;DR — How to Read an RJ45 Jack Datasheet

TL;DR: An RJ45 jack (the female socket / 母座, not the plug) hides real engineering in a short spec sheet. Read these lines and you've nailed 90% of the decision:

  • Data rate / category — 10/100M → 10GBASE-T. What speed the contacts are qualified for.
  • Integrated magnetics? — magjack (transformer built in) vs discrete (external LAN transformer).
  • PoE current rating — up to 1.5 A per contact. The same pins carry data + power, so this is independent of data rate. The most misread line on the sheet.
  • Mount — THT (through-hole, strongest) vs SMT (add board locks).
  • Tab up/down, angle (45/90/180°), shielding (UTP/STP) — mechanical fit + EMC.
  • Operating temp — 0~+70 °C commercial vs −40~+85/+105 °C industrial.
  • Durability — ≥ 750 mating cycles (IEC 60603-7).

Two gotchas engineers hit:

  • Dielectric withstanding voltage (1000 V AC, the connector's insulation) ≠ magjack isolation (≥1500 V rms, the transformer barrier).
  • Category is a channel property — a Cat6A jack only gives a Cat6A channel with Cat6A cable.

Sourced from IEC 60603-7, ANSI/TIA-568 and IEEE 802.3. VOOHU makes the jacks (母座) — standard, low-profile, offset, combination and integrated magjacks, 100M–10G, PoE 350 mA–1.5 A.

Full line-by-line guide → https://voohuelectronic-ux.github.io/voohu-rj45-guide/resources/how-to-read-rj45-jack-datasheet.html

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