ROHM Semiconductor BD7J201x Low Power Isolated Flyback Converter ICs

ROHM Semiconductor BD7J201x Low Power Isolated Flyback Converter ICs are designed for efficient and reliable isolated power supply applications. These ICs integrate a 120V switching MOSFET and operate over a wide input voltage range of 8V to 80V, making the ICs ideal for use in industrial equipment, home appliances, and energy systems. By utilizing primary-side regulation, the BD7J201x series eliminates the need for optocouplers, simplifying circuit design and improving long-term reliability. The ROHM Semiconductor BD7J201x devices support output power up to 7.5W, depending on the model and conditions, and feature built-in protections such as overcurrent, overvoltage, and thermal shutdown. The compact packaging (HTSOP-J8 or HSON8) and low standby power consumption make these devices suitable for space-constrained and energy-sensitive applications like PLCs, smart meters, and isolated gate drivers.

Features

  • No need for any optocouplers and third winding of transformers
  • Set the output voltage with two external resistors and the ratio of transformer turns
  • Adoption of the original adapter type technology that controls on-time
  • No need for external phase compensation parts for a high-speed load response
  • Low output ripple by a fixed switching frequency (at normal operation)
  • High-efficiency light load mode (at PFM operation)
  • Shutdown and enable control
  • Built-in 120V switching MOSFET
  • Soft start function
  • Load compensation function
  • Protection functions
    • Input Under Voltage Lockout (VIN UVLO)
    • Over Current Protection (OCP)
    • Over Voltage Protection (OVP)
    • Short Circuit Protection (SCP)
    • Thermal Shutdown (TSD)
    • Battery Short Protection (BSP)
    • Enable Over Voltage Protection (ENOVP)
  • Package options
    • HSON8 2.9mm x 3.0mm x 0.6mm package for BD7J201HFN-LB
    • HTSOP-J8 4.9mm x 6.0mm x 1.0mm package for BD7J201EFJ-LB
  • RoHS compliant

Applications

  • Industrial equipment
  • Home appliances
  • Building automation
  • Energy and infrastructures
  • General-purpose isolated power supplies

Specifications

  • Power supply voltage ranges
    • 8V to 80V for the VIN pin
    • 120V maximum for the SW pin
  • 1.80A typical over-current protection current
  • 400kHz typical switching frequency
  • ±1.6% reference voltage accuracy
  • 0μA typical shutdown current
  • 0.45mA typical switching operation current
  • -40°C to +125°C operating temperature range

Typical Application Circuit

Application Circuit Diagram - ROHM Semiconductor BD7J201x Low Power Isolated Flyback Converter ICs

Block Diagram

Block Diagram - ROHM Semiconductor BD7J201x Low Power Isolated Flyback Converter ICs
Published: 2025-05-20 | Updated: 2025-06-04