LM25180QNGURQ1

The LM25180-Q1 is a primary-side regulated (PSR) flyback converter with high efficiency over a wide input voltage range of 4.5V to 42V. 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 where only a single component crosses the isolation barrier. BCM switching delivers a compact magnetics solution with load and line regulation performance better than ±1.5%. The integrated 65V power MOSFET supports output power up to 7W and provides increased margin against line transients. The LM25180-Q1 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 forward voltage drop. Additional features include internal fixed or external programmable soft-start, an optional bias supply connection for improved efficiency, a precision enable input with hysteresis for adjustable line UVLO, hiccup-mode overload protection, and thermal shutdown with auto-recovery. The LM25180-Q1 is AEC-Q100 Grade 1 qualified and is available in an 8-pin WSON package with 0.8mm pitch and wettable flanks.

Applications

• Automotive body electronics
• Automotive powertrain
• Isolated bias power rails

Key features

• Compliant with device temperature grade 1 for automotive applications: -40°C to 125°C ambient temperature range
• Designed for reliable and durable applications
• 4.5V to 42V
• Stable and reliable solution with only one component crossing the isolation barrier
• ±1.5% total output voltage 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 of -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
• Low EMI operation compliant with CISPR 25
• High-efficiency PSR flyback operation
• Quasi-resonant switching in boundary conduction mode (BCM) under heavy load conditions
• External bias option for improved efficiency
• Single-output and multiple-output implementation options
• Create custom regulator designs using WEBENCH Power Designer