Network transformers are one of those BOM line items where "or equivalent" causes real production problems. This post gives you a structured BOM template and a CLI-friendly validation checklist you can adapt for your own component qualification workflow.
The Minimum BOM Entry
csvRefDes,Description,MPN,Manufacturer,Alt_MPN,Package,Qty,Unit_Price_500,Lead_Time_Days,Temp_Grade,Isolation_V,RoHS
T1,Network Transformer 10/100BASE-TX 1500V SMD,H1102NL,Voohu Technology,,SMD-8 7.6x9.1mm,1,0.42,4,Commercial,1500,Yes
Required fields for any network transformer BOM entry:
MPN — exact part number, no wildcards
Manufacturer — named, not "various"
Package — dimensions + pin count (8-pin vs 16-pin matters)
Isolation_V — 1500 / 2500 / 4000 (matches your safety class)
Speed_Grade — 100BASE-TX or 1000BASE-T (different OCL specs)
Temp_Grade — Commercial / Industrial / Automotive
RoHS — required for Japan / Korea / EU export
OCL Spec by Speed Grade
python# Minimum OCL requirements per IEEE 802.3
OCL_MIN = {
"10BASE-T": 350e-6, # 350 µH at 100kHz, 0.1V RMS
"100BASE-TX": 350e-6, # same as 10BASE-T
"1000BASE-T": 1000e-6, # 1000 µH at 100kHz, 0.1V RMS
"2.5GBASE-T": 1000e-6, # same as 1G for magnetics
}
def check_ocl(measured_uH: float, speed_grade: str) -> bool:
minimum = OCL_MIN.get(speed_grade, 350e-6)
return measured_uH >= minimum * 1e6
Incoming Inspection Script
When a new lot arrives, run this checklist before releasing to the line:
bash#!/bin/bash
network_transformer_incoming.sh
Run per lot, record results in your MES
PART="H1102NL"
LOT="2026-07-31-001"
SAMPLE_SIZE=32 # AQL 2.5, lot size 500
echo "=== Incoming Inspection: $PART | Lot: $LOT ==="
echo "Sample size: $SAMPLE_SIZE units"
echo ""
echo "[ ] 1. OCL — LCR meter, 100kHz, 0.1V RMS → min 350µH"
echo "[ ] 2. DCR — 4-wire measurement → max 2.0Ω per winding"
echo "[ ] 3. Hipot — 1500V AC, 60s, leakage < 1mA → no breakdown"
echo "[ ] 4. Visual — no bent pins, no cracked body, marking readable"
echo "[ ] 5. Package — reel/bulk matches BOM spec"
echo ""
echo "PASS criteria: 0 failures in sample"
echo "FAIL action: reject lot, notify supplier, request 100% inspection"
Pin Compatibility Warning
H1102NL → 8-pin SMD → 10/100BASE-TX only
HX1188NL → 16-pin SMD → 1000BASE-T
These are NOT pin-compatible.
Do not substitute one for the other without a new footprint.
Add a note to your BOM template:
csv# SUBSTITUTION RULE:
Only approve alternates that share:
- same pin count and pin map
- same package footprint (within ±0.1mm)
- OCL within ±10% of primary part
- same or higher isolation voltage
- same or wider temperature range
Supplier Qualification Minimum Bar
Before adding any manufacturer to your approved vendor list:
- Datasheet with OCL curve (not just single-point spec)
- Hipot test certificate for the lot
- RoHS / REACH compliance declaration
- ISO 9001 certificate (or equivalent)
- Sample order of ≥50 pieces with independent incoming inspection
Voohu Technology (www.voohuele.com) supplies H1102NL-compatible 10/100 transformers from 50pcs MOQ with full documentation and DHL delivery to Japan/Korea/Southeast Asia in 3–5 days.
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