ZXY-3529 Permalloy Audio Isolation Transformer, 1+1:1 / 4:1 Turns Ratio, 10 Hz-40 kHz, Hi-POT 1250 V, 8-Pin DIP, 35.0 x 29.0 x 26.0 mm
ZXY-3529 is a permalloy audio isolation transformer in an 8-pin DIP through-hole case measuring 35.0 × 29.0 × 26.0 mm. Two variants share the footprint: 1+1:1 at DCR 26 + 52 Ω max and +12 dBu input, and 4:1 at 700 Ω max and +22 dBu. Frequency range 10 Hz to 40 kHz, response within ±0.16 dB / ±0.10 dB from 20 Hz to 20 kHz, Hi-POT 1250 V.
- Turns ratio 1+1:1 or 4:1 on one part number, one 35.0 x 29.0 x 26.0 mm case
- Frequency range 10 Hz - 40 kHz; 20 Hz - 20 kHz within 0.16 dB (1+1:1), 0.10 dB (4:1)
- Maximum 50 Hz input at 1% THD +12 dBu (1+1:1) and +22 dBu (4:1)
- DCR 26 + 52 ohm max on the 1-4 side, 70 ohm max on the 5-8 side, both at 25 C
- Hi-POT 1250 V, 1 mA, 60 s; permalloy case; 8-pin DIP on a 5.0 mm pitch
1. Product Name
ZXY-3529 permalloy audio isolation transformer. 8-pin DIP through-hole package, turns ratio 1+1:1 or 4:1, frequency range 10 Hz to 40 kHz, Hi-POT 1250 V at 1 mA for 60 s, case 35.0 x 29.0 x 26.0 mm, pin pitch 5.0 mm, nameplate 150/600:10K.
Overview. A single part carries the whole isolation function: a permalloy can, a winding arrangement brought out to eight DIP terminals, and a nameplate that states the impedance designation and the model. Nothing else is needed on the board apart from the land pattern.
Two variants are specified on the same model number. They share the case, the land pattern and the pin assignments, and differ in winding: the 1+1:1 version for line-level coupling, the 4:1 version for higher input levels. The table in chapter 5 lists both columns side by side so the difference is visible without cross-referencing two documents.
2. Feature
Two turns-ratio variants on one part number. 1+1:1 for line-level coupling and 4:1 for higher input levels, both in the same 35.0 × 29.0 × 26.0 mm case.
Permalloy case. a high-permeability nickel-iron case with rounded corners, so the magnetic circuit is closed inside the can and the part is screened from nearby fields without a separate shield.
10 Hz to 40 kHz working range. the overall band; the ±0.16 dB / ±0.10 dB tolerance is specified from 20 Hz to 20 kHz, referred to +4 dBu at 1 kHz.
Input level to +22 dBu. maximum 50 Hz input at 1% THD, +12 dBu on the 1+1:1 variant.
DCR 26 + 52 Ω max. on the 1-4 side of the 1+1:1 variant, 70 Ω max on the 5-8 side, both at 25 °C.
Hi-POT 1250 V. 1 mA leakage limit for 60 s between winding and case.
8-pin DIP through-hole terminals. two rows of four on a 5.0 mm pitch, marked 5 6 7 8 on one row and 4 3 2 1 on the other, so the part is placed and soldered like any other DIP device.
Separate core and case terminals. pins 7 and 6 bring the internal core and the case out to the board when the design needs them bonded.
Orientation dot on the nameplate. with ZXY AUDIO TRANSFORMERS / 150/600:10K / ZXY-3529 laser marked.
Customized designs available. factory-direct supply from stock, with custom windings on request.
The case is the shield. There is no separate can, bracket or mu-metal wrapper to add at assembly: the permalloy body closes the magnetic path around the winding and the only thing the board has to provide is the eight holes and, where the design calls for it, a bond to pins 6 and 7.
3. Advantage
Protects the stage in front of it. the transformer decouples input from output, so a fault downstream cannot burn out the output stage driving the line.
Removes grounding hum. where two pieces of equipment are earthed at different points, the isolation is what takes the AC hum out that a direct connection would carry.
Balanced and unbalanced transmission. the same part reduces external interference in either arrangement, and couples voice or data between circuits that must not share a reference.
One footprint, two ratios. a design that moves from 1+1:1 to 4:1 keeps the same PCB land pattern, the same outline and the same panel cutout.
DIP terminals. through-hole mounting means straightforward replacement in the field and no reflow profile to re-qualify.
Tight response across the audio band. ±0.16 dB (1+1:1) and ±0.10 dB (4:1) from 20 Hz to 20 kHz, so the part does not colour the signal it passes.
Because both ratios sit in the same case, a design that moves from 1+1:1 to 4:1 keeps its PCB land pattern, its panel cutout and its assembly drawing. That is worth more than it sounds in a product that is often specified late in a project, after the board has already been laid out.
4. Application
Hi-Fi audio systems. between a source and a preamplifier or power amplifier where hum and ground loops are audible.
Home theater. isolating a processor output from a power amplifier input across a long cable run.
Car audio. breaking the ground path between a head unit and an external amplifier.
Mixing console signal isolation output. taking a console output to a recorder, a broadcast line or a stage feed without tying the grounds together.
Multi-channel isolated signal output. one part per channel where several outputs leave the same chassis.
The common thread across these uses is a ground that cannot be shared. Once two chassis sit on different earth potentials, a direct connection carries the difference as hum; the transformer passes the signal and not the difference, which is the entire job.
5. Application Specifications
Electrical data at 25 degrees C, as declared on the ZXY-3529 specification sheet.
5.1 Electrical specification
| Parameter | 1+1:1 | 4:1 |
|---|---|---|
| Turns ratio | 1+1:1 | 4:1 |
| DCR (1-4) / Ω max at 25 °C | 26 + 52 | 700 |
| DCR (5-8) / Ω max at 25 °C | 70 | 45 |
| Maximum 50 Hz input level, 1% THD | +12 dBu | +22 dBu |
| Freq. response, ref. +4 dBu at 1 kHz | 20 Hz - 20 kHz = ±0.16 dB | 20 Hz - 20 kHz = ±0.10 dB |
| Hi-POT, 1 mA, 60 s | 1250 V | 1250 V |
Overall frequency range is 10 Hz to 40 kHz; the ±0.16 dB and ±0.10 dB tolerances in the table are specified from 20 Hz to 20 kHz, referred to +4 dBu at 1 kHz. Hi-POT is 1250 V with a 1 mA leakage limit held for 60 s.
5.2 Construction and mechanical data
| Item | Value |
|---|---|
| Case | Permalloy (high-permeability nickel-iron) case with rounded corners |
| Package | 8-pin DIP through-hole, two rows of 4 terminals |
| Terminal-side marking | 5 6 7 8 on one row, 4 3 2 1 on the opposite row |
| Pin pitch | 5.0 mm |
| Case dimensions | 35.0 mm (W) × 29.0 mm (D) × 26.0 mm (H), case body only, terminals excluded |
| Winding arrangement | Windings between pins 1-3 and pins 2-4 (DCR 1-4); winding between pins 5-8 (DCR 5-8); pins 7 (core) and 6 (can) are the internal core and case terminals |
5.3 Winding and pin assignment
| Terminal | Function |
|---|---|
| Pins 1 - 3 | Primary winding, first section (measured as DCR 1-4 together with pins 2 - 4) |
| Pins 2 - 4 | Primary winding, second section |
| Pins 5 - 8 | Secondary winding (DCR 5-8) |
| Pin 7 | Core terminal |
| Pin 6 | Case (can) terminal |
6. Quality & Testing Assurance
Each parameter below is specified at 25 degrees C on the manufacturer specification sheet, and the part is marked CCC, CE, RoHS and UL.
| Test | Declared value |
|---|---|
| Dielectric withstand (Hi-POT) | 1250 V, 1 mA, 60 s |
| Turns ratio | 1+1:1 and 4:1, as tabulated |
| DC resistance at 25 °C | 26 + 52 Ω / 70 Ω max for 1+1:1; 700 Ω / 45 Ω max for 4:1 |
| Maximum 50 Hz input at 1% THD | +12 dBu (1+1:1) and +22 dBu (4:1) |
| Frequency response, ref. +4 dBu at 1 kHz | 20 Hz - 20 kHz within ±0.16 dB (1+1:1) and ±0.10 dB (4:1) |
| Test ambient | All electrical parameters specified at 25 °C |
Brand / manufacturer: ZXY, Shenzhen Zhixiangyuan Electronics Co., Ltd. http://www.zxycoil.com