STK7226 Datasheet, Sanyo VTR Secondary Chopper Regulator, Pinout and Faults

User question

fisa tehnica STK 7226

Artificial Intelligence Response

Direct answer to the question

The STK7226 / STK 7226 is an obsolete Sanyo hybrid voltage-regulator module, used mainly in VTR/VCR power supplies as a secondary chopper regulator. A complete original Sanyo datasheet is difficult to find publicly, but the available technical references indicate:

• Function: secondary chopper regulator for VTR/VCR power supply.
• Manufacturer/brand: Sanyo.
• Technology: hybrid IC/module, not a simple monolithic IC.
• Likely package: SIP/ZIP-style power hybrid module.
• Internal structure: pins 6–15 belong to the DC/DC converter section supplied from about 40 V DC, while pins 1–5 form a more conventional stabilizer/regulator section. This is based on a Polish technical extract hosted as an STK7226 datasheet entry. (datasheet4u.com)
• Status: obsolete / surplus-only part; current component listings show it as a used, hard-to-find Sanyo module for VTR applications. (utsource.net)

I would not treat the 5.1 V / 13 V / 4 A figures sometimes circulated online as confirmed manufacturer data unless you verify them from the service manual of the exact VCR model or from the original Sanyo application sheet.

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Detailed problem analysis

The safest technical description is:

STK7226 is a Sanyo hybrid secondary-side chopper regulator module for video recorder power supplies.

It is part of the broader Sanyo STK72xx family, many of which are described in datasheet indexes as secondary chopper regulators for VTR. Alldatasheet, for example, does not show a complete exact STK7226 manufacturer datasheet, but it lists nearby STK72xx parts such as STK7210, STK7216, STK7217, STK7221, STK7230, STK7231, STK7240 and STK7241 as VTR chopper-regulator devices. (alldatasheet.com)

The most useful available technical fragment for STK7226 specifically states that the hybrid IC allows construction of:

Section	Pins	Function
Conventional stabilizer section	1–5	Linear/classic stabilizer-type regulator
Chopper converter section	6–15	DC/DC converter supplied from approximately 40 V DC

This means the STK7226 is not just a three-terminal regulator. It is a power-supply hybrid block that likely contains switching/control elements and requires external components such as capacitors, inductors, diodes, resistors and possibly feedback components on the VCR power board. (datasheet4u.com)

A seller listing also identifies the part as “STK7226 SECONDARY CHOPPER REGULATOR FOR VTR”, branded Sanyo, with used parts appearing in surplus stock. (utsource.net)

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Important caution about datasheet accuracy

There are conflicting and low-quality online references for this part. For example, one component marketplace correctly lists STK7226 as a Sanyo secondary chopper regulator, but the same page also contains an obviously unrelated/generated description of “STK7226” as a GSM mobile phone. That section should be ignored. (utsource.net)

Therefore, for repair work, the best technical source is usually the service manual of the device where the STK7226 is installed, not a generic online part listing.

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Practical pinout guidance

Based on the available STK7226 extract:

Pins 1–5

These are associated with a classic stabilizer/regulator section. In a VCR this may provide a lower-voltage rail for logic/control circuits.

Pins 6–15

These are associated with the chopper converter section, supplied by an unregulated DC rail of about 40 V DC. This section probably generates one of the main secondary supply rails for the VCR mechanism, motors, servo circuits or analog sections.

Because the complete official pinout is not confirmed, do not randomly power the module on the bench. Identify the pins from the original PCB tracks first.

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Practical repair guidelines

If you are repairing equipment using STK7226:

1. Find the VCR/service manual

   • Search by the equipment model, not only by “STK7226 datasheet”.
   • Look for the power-supply schematic.
   • The schematic will usually show the real pin functions and output voltages.

2. Check for short circuits

   • With power disconnected, measure resistance between the high-voltage input pins, output pins and ground.
   • A near-short between the chopper supply and output pins often indicates a failed hybrid module.

3. Check external electrolytic capacitors

   • Old VCR power supplies often fail because of high-ESR capacitors.
   • Replace bad capacitors before condemning the STK7226.
   • Use low-ESR capacitors with proper ripple-current rating.

4. Check startup/fusible resistors

   • If the unit is dead, inspect fusible resistors and rectifier diodes around the regulator.
   • Do not replace a blown fusible resistor without checking whether the STK7226 is shorted.

5. Use an isolation transformer and current limiting

   • These are offline or quasi-offline power-supply circuits.
   • Use a series bulb limiter or bench current limit when powering after repair.

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Replacement notes

There appears to be no reliable pin-for-pin modern replacement for STK7226. If the module is defective, practical options are:

Option	Comment
Used/NOS STK7226	Possible from surplus sellers, but authenticity and condition are uncertain.
Donor board	Often safer for vintage VCR repair.
Custom replacement board	Possible, but requires knowing the original output voltages, currents and feedback arrangement.
Modern DC/DC converters	Can replace individual rails only after tracing the original circuit.

Do not substitute another STK72xx part unless the service data confirms identical pinout, output voltages and application circuit.

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What I need to help further

If you want the actual pinout or a replacement proposal, send:

• the brand and model of the VCR/equipment;
• a photo of the PCB around the STK7226;
• the markings on the module;
• measured voltages, if available;
• whether the device is dead, cycling, overheating, or producing low voltage.

With that, I can help reconstruct the practical pin functions and suggest a safe repair/replacement method.

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Brief summary

The STK7226 is an obsolete Sanyo hybrid secondary chopper regulator for VTR/VCR power supplies. A complete official datasheet is not readily available, but a technical extract indicates that pins 1–5 form a classic stabilizer section and pins 6–15 form a DC/DC chopper converter section supplied from about 40 V DC. For actual repair, the service manual of the exact equipment is the most reliable source.

Disclaimer: The responses provided by artificial intelligence (language model) may be inaccurate and misleading. Elektroda is not responsible for the accuracy, reliability, or completeness of the presented information. All responses should be verified by the user.