Texas Instruments LM5181

Description

The LM5181 is a primary-side regulated (PSR) fly back converter with high efficiency over a wide input voltage range of 4.5 V to 65 V. The isolated output voltage is sampled from the primary-side fly back voltage,eliminating the need for an optocoupler, voltage reference,or third winding from the transformer for output voltage regulation.The high level of integration results in a simple,reliable and high-density design with only one component crossing the isolation barrier. Boundary conduction mode (BCM) switching enables a compact magnetic solution and better than ±1.5% load and lineregulation performance. An integrated 100-V power MOSFET provides output power up to 4 W with enhanced headroom for line transients.The LM5181 fly back converter is available in a 8-pin,4-mm × 4-mm,thermally enhanced WSON package with 0.8-mm pin pitch.

Features

• Functional Safety-Capable
• Documentation available to aid functional safetysystem design
• Designed for reliable and rugged applications
• Wide input voltage range of 4.5 V to 65 V withoperation down to 3.5 V after start-up
• Robust solution with only one componentcrossing the isolation barrier
• ±1.5% total output regulation accuracy
• Optional VOUT temperature compensation
• 6-ms internal or programmable soft start
• Input UVLO and thermal shutdown protection
• Hiccup-mode overcurrent fault protection
• –40°C to +150°C junction temperature range
• Integration reduces solution size and cost
• Integrated 100-V, 0.4-Ω power MOSFET
• No opto-coupler or transformer auxiliarywinding required for VOUT regulation
• Internal loop compensation
• High-efficiency PSR flyback operation
• Quasi-resonant MOSFET turn-off in BCM
• Low input quiescent current
• External bias option for improved efficiency
• Single- and multi-output implementations
• Ultra-low conducted and radiated EMI signatures
• Soft switching avoids diode reverse recovery
• Optimized for CISPR 32 EMI requirements
• Create a custom regulator design usingWEBENCH® Power Designer

Typical applications

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

More information

• Datasheet
• IC product information