TOP256EN Datasheet: Analysis


TOP256EN Datasheet: Analysis

Power Integrations’ TOP256EN switcher integrated circuit

TOP256EN is a member of the TOPSwitch family of switcher integrated circuits (ICs) developed by Power Integrations. It is a high-performance monolithic switch mode power supply (SMPS) controller designed for offline power conversion applications. The TOP256EN incorporates a range of features and capabilities that make it suitable for designing efficient and reliable power supplies.

TOP256EN Key Features and Applications

Some of the key TOP256EN features include:

  • Integrated Controller: The TOP256EN combines a high-voltage power MOSFET (metal-oxide-semiconductor field-effect transistor), control circuitry, and protection features into a single package. This integration simplifies the design process, reduces component count, and improves overall reliability.
  • Flyback Topology: The TOP256EN is used in flyback power supply topologies. A flyback converter is a type of SMPS that stores energy in the magnetic field of a transformer during the switch-on period and transfers it to the load during the switch-off period. This topology is commonly employed in low-to-medium power applications.

Typical Flyback Application

Typical Flyback Application (Source: Power Integrations)

  • Wide Input Voltage Range: The TOP256EN can accommodate a wide range of input voltages, typically spanning from 85V to 265V AC. This makes it suitable for power supply designs intended for different regions with varying voltages.
  • Output Power Range: The TOP256EN is designed for power supplies with output power ranging from a few watts to several tens of watts. Its power capability makes it suitable for various applications across multiple industries.
  • Energy Efficiency: The TOP256EN uses advanced control algorithms and low-loss components to maximize energy efficiency. It achieves high efficiency by regulating the switching frequency based on load conditions and employing other techniques to minimize power losses.
  • Protection Features: The TOP256EN incorporates several protection features to ensure safe and reliable operation. These include overvoltage protection, overload protection, thermal management, and line undervoltage lockout. These protections help safeguard the power supply and the connected devices from potential faults or abnormal operating conditions.

The TOP256EN is commonly used in various electronic devices and applications, including:

  • LCD monitors
  • Personal computers
  • Small servers
  • Laptop adapters
  • Set-top boxes
  • Digital TVs
  • Printers
  • DVD players and recorders
  • Video games
  • Broadband modems
  • Cellular phone adapters
  • Audio amplifiers

Using the TOP256EN Datasheet

The TOP256EN is a versatile and efficient SMPS that offers designers the flexibility and performance required for various applications. Its integration, wide input voltage range, and protection features make it a popular choice in the field of power supply design.

Important TOP256EN Specifications

Output Power (Max) – Open Frame, 230V

119.00 W

Output Power (Max) – Enclosed, 230V

60.00 W

Output Power (Max) – Enclosed, Univ

40.00 W

Output Power (Max) – Open Frame, Univ

86.00 W

Switching Frequency (max)

132 kHz

Breakdown Voltage

700 V

Voltage – Input (Min)

85 V

Voltage – Input (Max)

265 V

Auto-Restart & Overvoltage Response


Auto-Restart Threshold


IC Package


Internal Switch


Mounting Type

Through Hole

Over-Temperature Response


Temperature – Operating (Min)

-40 °C

Temperature – Operating (Max)

150 °C

Control Scheme


Control Features

  • Selectable Current Limit
  • Frequency Jittering
  • Soft Start
  • Auto-Restart/Latching Fault Response
  • On/Off Control

Protection Features

  • Output Undervoltage
  • Overtemperature
  • Output Overvoltage
  • Output Short Circuit
  • Output Open Loop
  • Output Overload
  • Remote Shutdown



Product Sub-Type


Secondary Response


TOP256EN Specifications (Source: Power Integrations)

You can find detailed information, such as performance characteristics, on the TOP252-262 TOPSwitch-HX Family datasheet in addition to the data presented above.

Optimizing Your TOP256EN PCBA Design

For the best TOP256EN implementation, the datasheet should be used along with accurate CAD models to help ensure optimal PCBA development.

UL CAD models of the TOP256EN

TOP256EN CAD data from UL

For electronic product development to be efficient, your PCBA design and manufacturing stages must be collaborative and supportive. You should begin with a reliable component library where you can be assured of the accuracy of the data and models.

If you’re looking for CAD models for common components or design tips like how to best use the TOP252-262 TOPSwitch-HX Family datasheet, Ultra Librarian helps by compiling all your sourcing and CAD information in one place.

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