EI14 600 Ω: 600 Ω Audio Isolation Transformer - 1:1 Vertical PCB Through-Hole Hard Pins | 300 mH Inductance | 1000 VAC Withstand Voltage | Voice Band 300 Hz - 3.5 kHz

1. Product Name

EI14 vertical audio isolation transformer, 600 Ω: 600 Ω. Reference model ZXY-B2127-2 (EI14 series, hard pin version).

This transformer is a compact, PCB-mountable low-frequency component that provides electrical isolation and clean signal transfer between two equal-impedance audio circuits. It uses a cold-rolled silicon steel core with a V-0 flame-retardant bobbin, and is supplied in a vertical through-hole hard-pin package with rigid pins for stable and easy board-level assembly.

2. Product Features

600 Ω : 600 Ω Impedance Matching — 1:1 turns ratio (1-3 : 4-6), tolerance ±2%, two identical 600 Ω lines are isolated without any impedance transformation.

Parallel Inductance 300 mH — Measured at 1 kHz / 0.25 V, 1-3 = 4-6 = 300 mH, tolerance ±25%.

Low DC Resistance — Primary (1-3) is 82 Ω ±15%, secondary (4-6) is 102 Ω ±15%.

Low Insertion Loss — Maximum ≤2 dB at 1 kHz, ensuring signal level remains intact across the isolation barrier.

Voice Band Frequency Response — 300 Hz - 3.5 kHz, tolerance ±2 dB.

Dielectric Strength 1000 VAC — Isolation between primary and secondary, sustained for 2 seconds at 1 mA.

Cold-Rolled Silicon Steel Core — High permeability, ultra-low magnetic loss, efficiency ≥90%.

V-0 Flame-Retardant Bobbin — High dielectric strength and thermal stability; 130 °C / 155 °C double-insulated magnet wire.

Vertical Hard-Pin Package — Through-hole pins occupy minimal PCB area and provide mechanically stable, automation-friendly mounting.

3. Product Advantages

Direct Replacement for Existing Layouts — The vertical hard-pin package and 1:1 turns ratio allow this component to replace existing 600 Ω isolation transformers without redesigning boards or networks.

Maintains Signal Integrity — Low insertion loss and a window of ±2 dB in the 300 Hz - 3.5 kHz range preserve voice band quality.

Efficient Magnetic Circuit — High-permeability silicon steel core operates at ≥90% efficiency with extremely low magnetic loss.

Temperature Stability — Double-insulated high-temperature magnet wire maintains electrical performance over the -40 °C to +85 °C operating range.

Breaks Ground Loops — Electrical isolation separates two circuits, protecting sensitive downstream circuits.

Compact Size, Secure Mounting — Vertical pin layout reduces board surface area while providing mechanically secure through-hole solder joints.

Configurable Series — 210 mH and 420 mH versions of the 600 Ω : 600 Ω are available on request, as well as 1:10, 1:13, and 1:16 step-up versions.

4. Application Areas

The EI14 is suitable for voice-band signal isolation and applications where a 600 Ω interface is required and ground loops cause hum:

Audio Communication and Intercom Systems — Voice signal isolation between lines and handsets or door stations.

Wired Telephones and Intercom Doorbells — Compact board-level 600 Ω line interface isolation.

Voice Signal Isolation and Pure Audio Transmission — Eliminates ground loops and resulting hum.

Instrumentation Signal Isolation — Isolates measurement frontends from driven equipment.

Low-Voltage Detection Circuits — Isolated sensing for low-level lines.

Industrial and Portable Control Modules — 600 Ω interface circuits requiring electrical isolation in compact dimensions.

5. Application Specifications

5.1 Environmental Conditions

5.2 Electrical Specifications at 25 °C

5.3 Materials and Construction

5.4 Physical Dimensions, in inches, per datasheet

Other EI14 configurations are available on request: 600 Ω : 600 Ω versions with parallel inductance of 210 mH and 420 mH, and 1 : 10, 1 : 13, and 1 : 16 step-up versions.

6. Quality and Test Assurance

Every unit is 100% inspected before shipment. Dielectric strength is verified at 1000 VAC between primary and secondary for 2 seconds; insulation resistance is confirmed at a minimum of 100 MΩ with 500 V DC applied; temperature rise is checked to remain within 42 °C under full load. DC resistance, inductance, turns ratio, insertion loss, and frequency response are all measured at 1 kHz according to the limits in Section 5.2.

This transformer is RoHS compliant and manufactured under an ISO 9001:2015 certified quality management system, while meeting CCC, CE, RoHS, and UL compliance requirements.