1 Features
• Functional Safety-Capable
– Documentation available to aid functional safety
system design
• 4.5-V to 100-V wide input voltage range
• Extended power range from less than 1 W to more
than 50 W
• Robust PSR flyback design for reliable and rugged
applications
– Robust design with only a transformer crossing
the isolation barrier
– ±1.5% total output regulation accuracy
– Optional VOUT temperature compensation
– Input UVLO and thermal shutdown protection
– Hiccup-mode overcurrent fault protection
– 0.9-mm HV-LV pin spacing in 14-pin HTSSOP
package
– –40°C to +150°C junction temperature range
• Integration reduces design size and cost
– No optocoupler or transformer auxiliary winding
required for VOUT regulation
– 2-A peak sink and 1-A peak source high-current
power MOSFET gate driver
• High efficiency with best-in-class active IQ
– Quasi-resonant switching in boundary
conduction mode (BCM) at heavy load
– External VCC option for improved efficiency
– High light-load efficiency with lowest IQ (25-μA
typical with external VCC)
– Single and multiple output implementations
• Ultra-low conducted and radiated EMI signatures
– Soft switching avoids diode reverse recovery
– Designed for CISPR 32 EMI requirement
• Create a custom design using LM5185 with
WEBENCH® Power Designer
2 Applications
• Factory automation and control: Isolated field
transmitters, field actuators, and multiple output
rails for analog input modules
• Motor drives: IGBT and SiC gate drive supplies
• Solar energy systems: Micro inverter and Solar
power optimizer
• PoE PD DC/DC converters
• Building automation HVAC systems
• Generic isolated bias power rails for industrial and
telecom systems
• Generic IGBT, MOSFET, GaN and SiC gate drivers
3 Description
The LM5185 is a primary-side regulated (PSR)
flyback controller with high efficiency over a wide
input voltage range of 4.5 V to 100 V. The
isolated output voltage is sampled from the primaryside
flyback voltage, eliminating the need for an
optocoupler, voltage reference, or third winding from
the transformer for output voltage regulation.