1 Features

• Functional Safety-Capable

– Documentation available to aid functional safety

system design

• 4.5-V to 42-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 LM25185 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 LM25185 is a primary-side regulated (PSR)

flyback controller with high efficiency over a wide

input voltage range of 4.5 V to 42 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.