LM25180NGUR

The LM25180 is a primary-side regulated (PSR) flyback converter with high efficiency over a wide 4.5V to 42V input voltage range. The isolated output voltage is sensed from the primary-side flyback voltage, eliminating the need for an optocoupler, voltage reference, or transformer tertiary winding for output voltage regulation. The high level of integration enables simple, reliable, high-density designs with only a single component crossing the isolation barrier. Boundary conduction mode (BCM) switching enables a compact magnetic solution and load and line regulation performance better than ±1.5%. The integrated 65V power MOSFET supports up to 7W output power and provides increased margin against line transients. The LM25180 converter simplifies the implementation of isolated DC/DC power supplies, with optional features to optimize performance for target end equipment. The device sets the output voltage with a single resistor, while an optional resistor improves output voltage accuracy by compensating for the thermal coefficient of the flyback diode voltage drop. Additional features include internal fixed or external programmable soft-start, optional bias supply connection for higher efficiency, precision enable input with hysteresis for adjustable line UVLO, hiccup-mode overload protection, and thermal shutdown with auto-recovery. The LM25180 flyback converter is available in an 8-pin 4mm×4mm thermally enhanced WSON package with 0.8mm pin pitch.

Applications

• Isolated field transmitters and field actuators
• Multi-output rails for analog input modules
• Motor drives: IGBT gate driver power supplies
• Building automation
• HVAC systems

Key features

• Designed for reliable and durable applications
• 4.5V to 42V
• Reliable solution with only one component crossing the isolation barrier
• ±1.5% total output regulation accuracy
• Optional VOUT temperature compensation
• 6ms internal or programmable soft-start
• Input UVLO and thermal shutdown protection
• Discontinuous mode overcurrent fault protection
• Junction temperature range: -40°C to +150°C
• Reduced solution size and cost through integrated technology
• Integrated 65V, 0.4Ω power MOSFET
• VOUT regulation without optocoupler or transformer auxiliary winding
• Internal loop compensation
• Low EMI operation, compliant with CISPR 32
• High-efficiency PSR flyback operation
• Quasi-resonant switching in boundary conduction mode (BCM) under heavy load
• Low input quiescent current
• External bias option for improved efficiency
• Single-output and multi-output implementation support
• Create custom regulator designs using WEBENCH Power Designer