SMD Audio Isolation Transformer, ED8-600Ω to 600Ω, 1:1, 6-Pin, 10.5 mm, 1250 V AC Withstand Voltage

1. Product Name

A 600-ohm to 600-ohm audio isolation transformer in a surface-mount package. The two windings are 1:1, so the device provides galvanic isolation in a line-level path rather than acting as a matching transformer: the voltage across it remains unchanged, only the ground connection between the two sides is removed. Six gull-wing leads, three per side, mount it on the PCB like any other SMD component, which is exactly why it coexists with the through-hole parts it replaces.

None of the ten panels carry a model or part number, including the two titled panels and one showing the specification table. The device is therefore identified by its electrical description — 600Ω to 600Ω, 1:1 in a 6-pin SMD package — and by its dimensions. If you need a BOM code, ask your supplier which number they use; this page does not invent one.

2. Functional Description

When two grounded devices share the same mains supply, a loop forms between their shields, and current in that loop adds hum at the mains frequency and its harmonics to the signal. Inserting a transformer in the path eliminates the loop because no conductive connection remains between the two ground points. The 1:1 turns ratio is used where the level must stay the same: the device sits in series with the signal path, and the receiving stage sees the same impedance as before. The same arrangement also cuts the path by which digital noise travels between converters and amplifiers sharing a ground.

3. Construction

The core is a laminated stack of high-permeability material, visible as silver laminations above and below the coil, with the two windings mounted on a molded bobbin between the two core halves. The coils are multilayer wound from enameled copper wire, and the entire winding is wrapped in a high-gloss amber heat-shrink film, which is the device's most distinctive feature. The leads are gull-wing style, stamped and tin-plated from the lead frame, extending from both long sides of the molded body so the device sits flat on the board.

4. Dimensions and Pad Layout

Only one side of the drawing is dimensioned — the long side. The body measures 10.5 mm long and 4.7 mm high, both marked as maximum values, and a third dimension reads 8.5 mm (maximum), drawn at the lead ends in the same view but left unnamed. What the drawing does not give is the depth — which is precisely what a pad layout needs — nor lead spacing, pad dimensions, or pin numbering. The pad-layout note below the drawing reads simply "6-pin SMD horizontal."

5. Electrical Specifications

The specification box is the entire electrical data, and it is brief. Impedance is 600Ω to 600Ω, 1:1, 2% tolerance; inductance is 2.0 H or higher (measured at 250 Hz, 0.5 V); DC resistance is 66Ω and 81Ω, ±15%; and the dielectric withstand test is 1250 V AC, 1 mA, 2 s. The table header fixes the test temperature at 25°C. Nothing else is present: frequency response, insertion loss, rated level, THD, insulation resistance, and operating temperature range are absent from the specification.

5.1 Published Parameters

6. Measured Data

A photograph shows the device connected through probe leads to a digital audio analyzer, with the instrument reading 0.00023% THD+N at 1.000 kHz, a level of -7.10 dBFS, and a SINAD of 112.5 dB. This is a single-unit test observation under a specific setup, not a guaranteed value: drive level, source impedance, load, and measurement bandwidth are not shown in the figure, and none of these figures are repeated in the specification table above.

7. Packaging

The packaging is stated as tape and reel for SMT batch assembly, shown by three units displayed side by side. The reel, tape, carrier, or cover tape does not appear in the photograph, and no reel quantity, carrier pitch, tape width, or orientation is given. The three units in the figure share the same length with a slight apparent height variation, most likely a camera-angle artifact rather than a second height option, but the documentation does not say so either.

8. Quality and Compliance

The compliance panel prints four marks under the heading "International Certifications and Standards": CCC, CE, RoHS, and UL Recognized. The UL Recognized mark is a component recognition, not a listing of a finished device, and by itself does not prove the end product is compliant. None of the four marks is accompanied by a certificate number, standard reference, file number, or test report; the only dielectric strength data in the documentation is the 1250 V AC withstand rating in the specification table.

9. Features

1:1 at 600Ω. The turns ratio is fixed by the impedance match, so the device does not change signal level when inserted.

Six-pin SMD. Gull-wing leads on a 10.5 mm body let the part be placed and reflowed with the rest of the board.

1250 V AC isolation. Enough to break ground loops and keep faults off the connector, tested at 1 mA for 2 s.

2.0 H inductance. Measured at 250 Hz and 0.5 V, this guarantees the low end of the band does not load the source.

Laminated high-permeability core. The laminated rather than solid core is what lets a small audio part reach the needed inductance at this size.

Amber heat-shrink encapsulation. The winding is sealed under a high-gloss film, protecting the fine magnet wire during handling and reflow.

10. Advantages

It eliminates ground loops rather than filtering them. A ground loop is a circuit problem; a transformer breaks the circuit. Nothing in the signal path is attenuated or added beyond the device itself.

The electrical parameters are concise and unambiguous. Impedance with tolerance, inductance with test conditions, two DC resistance values, and a withstand test with current and duration — these five figures are exactly what design needs.

Isolation parameters come with test conditions. 1250 V AC, 1 mA, for 2 s is a definite test condition, not a marketing number.

SMD rather than through-hole. The same function as a through-hole line transformer in a part that fits an existing reflow process.

Test-bench data is shown. The analyzer photo shows 0.00023% THD+N at 1 kHz, a starting point for discussing guaranteed limits.

11. Specifications

Values are transcribed from the supplier panels. Missing entries are marked "not stated," and characteristics the material never mentions are left explicitly blank rather than guessed.

12. Applications

The following applications are the uses the material points to, with a note on why a 1:1 device fits each one. They describe the intended market for the part, not a certification of any particular design.

Ground-loop elimination. Between two grounded devices sharing a mains supply, where the ground loop appears as audible hum at the mains frequency.

Converter and DAC outputs. The photo on this page shows the part on a high-resolution DAC board, between the conversion stage and the analog output connector.

Balanced and unbalanced interfaces. Where a line output must feed an input on a different ground reference with no DC path.

Digital noise isolation. Between digital sources and analog stages, keeping converter noise out of the shared ground.

Broadcast and installation audio. Long line runs between rooms or racks, both ends grounded independently.

Instrumentation front ends. Low-level inputs that must tolerate ground potential differences between sensor and recorder.

13. Ordering Information

Start with the application, then give the parameters. A useful inquiry states what the device connects at both ends, gives the impedance and turns ratio, notes whether a center tap is required and on which winding, and provides the pinout if a PCB already exists. Also state the packaging, the reel quantity needed for the line, and the order quantity per shipment and per batch. Since no model number is published, the product description and drawing carry the identification.

Compliance note: the panels show CCC, CE, RoHS, and UL Recognized marks and state that all four cover the device. None of the four marks carries a certificate number, standard number, or test report, and UL Recognized is component recognition rather than a complete equipment listing. This page reports the marks and claims as printed, not as verified certifications. If your product must meet a specific standard, obtain the certificate and report for that standard before the part is designed in.

Brand/Manufacturer: ZXY, Shenzhen Zhixiangyuan Electronics Co., Ltd. http://www.zxycoil.com