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.