EI14 600 Ohm : 600 Ohm Audio Isolation Transformer - 1:1 Vertical PCB Through-Hole Hard Pin | 300 mH Inductance | 1000 VAC Hi-Pot | Voice Band 300 Hz - 3.5 kHz
EI14 600 Ω : 600 Ω vertical audio isolation transformer on rigid through-hole pins: 1:1 ratio, 300 mH, ≤2 dB insertion loss, 300 Hz – 3.5 kHz, 1000 VAC isolation.
- 600 Ω : 600 Ω with a 1:1 turn ratio (1-3 : 4-6) within ±2%
- Parallel inductance 300 mH ±25%; DCR 82 Ω (1-3) and 102 Ω (4-6)
- Insertion loss ≤2 dB max at 1 kHz; 300 Hz – 3.5 kHz within ±2 dB
- 1000 VAC primary-to-secondary isolation at 1 mA for 2 s
- Cold-rolled silicon steel core, V-0 bobbin, 130 °C / 155 °C wire, vertical hard pins
Reference part number ZXY-B2127-2. RoHS compliant; CCC, CE and UL compliance; ISO 9001:2015 certified manufacturing.
1. Product Name
EI14 Vertical Audio Isolation Transformer, 600 Ω : 600 Ω. Reference part number ZXY-B2127-2 (EI14 series, hard-pin version).
The transformer is a compact, PCB-mountable low-frequency part that provides galvanic isolation and clean signal transfer between two audio circuits of equal impedance. It is built on a cold-rolled silicon steel core with a V-0 flame-retardant bobbin and is supplied in a vertical through-hole format with rigid pins for stable, assembly-friendly board mounting.
2. Feature
600 Ω : 600 Ω impedance matching — 1:1 turn ratio (1-3 : 4-6) within ±2%, so two identical 600 Ω lines are isolated without any impedance conversion.
Parallel inductance 300 mH — measured at 1 kHz / 0.25 V, 1-3 = 4-6 = 300 mH within ±25%.
Low DC resistance — 82 Ω ±15% on the primary (1-3) and 102 Ω ±15% on the secondary (4-6).
Low insertion loss — ≤2 dB max at 1 kHz keeps the signal level intact through the isolation barrier.
Voice-band frequency response — 300 Hz - 3.5 kHz within ±2 dB.
Withstand voltage 1000 VAC — primary-to-secondary isolation at 1 mA for 2 s.
Cold-rolled silicon steel core — high permeability with ultra-low magnetic loss, efficiency ≥90%.
V-0 flame-retardant bobbin — high dielectric strength and thermal stability; 130 °C / 155 °C dual-insulation wire.
Vertical hard-pin package — through-hole pins give a small PCB footprint and a mechanically secure, automation-friendly mount.
3. Advantage
Drop-in for existing layouts — the vertical hard-pin format and 1:1 ratio let the part replace an existing 600 Ω isolation transformer without redesigning the board or the network.
Signal integrity kept — low insertion loss and a ±2 dB window across 300 Hz - 3.5 kHz preserve voice-band quality.
Efficient magnetic path — the high-permeability silicon steel core runs at ≥90% efficiency with very low magnetic loss.
Stable over temperature — dual-insulation high-temperature wire holds electrical performance across the -40 °C to +85 °C operating range.
Breaks ground loops — galvanic isolation separates the two circuits and protects sensitive downstream circuitry.
Small, secure footprint — vertical pin layout keeps board area low while giving a mechanically secure through-hole joint.
Configurable family — 210 mH and 420 mH 600 Ω : 600 Ω versions and 1:10, 1:13 and 1:16 step-up versions are available on request.
4. Application
The EI14 is intended for voice-band signal isolation and for 600 Ω interface duty in equipment where a ground loop would otherwise carry hum:
Audio communication and intercom systems — voice signal isolation between line and handset or door station.
Wired landline telephones and intercom doorbells — 600 Ω line interface isolation on a compact board.
Voice signal isolation, clean audio transmission — removes the ground loop and the hum it carries.
Instrumentation signal isolation — separates a measurement front end from the equipment it feeds.
Low-voltage detection circuits — isolated sensing of a low-level line.
Industrial and portable control modules — 600 Ω interface circuits that need galvanic isolation in a small footprint.
5. Application Specifications
5.1 Environmental conditions
| Item | Specification |
|---|---|
| Storage temperature range | -45 °C to +125 °C |
| Operating temperature range | -40 °C to +85 °C |
| Relative humidity range | 5% to 95% |
| Temperature rise | 42 °C max under full load |
5.2 Electrical specification at 25 °C
| Item | Specification |
|---|---|
| DC resistance (DCR) | 1-3 = 82 Ω ±15%; 4-6 = 102 Ω ±15% |
| Inductance @ 1 kHz, 0.25 V (parallel) | 1-3 = 4-6 = 300 mH ±25% |
| Impedance @ 1 kHz | Primary 600 Ω; secondary 600 Ω |
| Insertion loss | ≤2 dB max @ 1 kHz |
| Frequency response | 300 Hz - 3.5 kHz, ±2 dB |
| Frequency response @ 20 Hz | 20 dB max / 25 dB max (by customer test mode) |
| Turn ratio | 1-3 : 4-6 = 1 : 1 ±2% |
| Withstand voltage (Hi-Pot) | 1000 VAC, 1 mA, 2 s (primary to secondary) |
| Insulation resistance | ≥100 MΩ @ 500 V DC |
| Flammability | V-0 grade plastic bobbin |
| Mounting method | Vertical PCB through-hole pins |
| Compliance | RoHS |
5.3 Materials and construction
| Item | Specification |
|---|---|
| Core | Cold-rolled, high-permeability silicon steel |
| Bobbin | V-0 flame-retardant plastic |
| Winding wire | 130 °C / 155 °C dual-insulation high-temperature wire |
| Terminals | Vertical PCB through-hole pins (hard pin) |
| Pin layout | Vertical through-hole pins numbered 1-2-3 / 6-5-4 (bottom view) |
5.4 Outline dimensions, unit inch, as printed on the data sheet
| Item | Specification |
|---|---|
| Overall width (front view) | .610 Max (inch) |
| Overall depth (top view) | .590 Max (inch) |
| Overall height (front view) | .511 Max (inch) |
| Pin blade thickness | .027 (inch) |
| Reference dimensions | .138 ref and .433 ref (inch) |
Alternative EI14 configurations are available on request: 600 Ω : 600 Ω versions with 210 mH and 420 mH parallel inductance, and 1 : 10, 1 : 13 and 1 : 16 step-up versions.
6. Quality & Testing Assurance
Every unit is 100% inspected before shipment. Dielectric strength is verified at 1000 VAC for 2 s between primary and secondary; insulation resistance is confirmed to be at least 100 MΩ with 500 V DC applied; and temperature rise is checked to remain within 42 °C under full load. DC resistance, inductance, turn ratio, insertion loss and frequency response are measured at 1 kHz against the limits in section 5.2.
The transformer is RoHS compliant and is manufactured under an ISO 9001:2015 certified quality management system, with CCC, CE, RoHS and UL compliance.