1FEATURES

2• Self-synchronization to Main Channel Output

• Free-run Mode for Buck Regulation of DC

Input

• Leading Edge Pulse Width Modulation

• Voltage-mode Control with Current Injection

and Input Line Feed-forward

• Operates from AC or DC Input up to 42V

• Wide 4.5V to 30V Bias Supply Range

• Wide 0.75V to 13.5V Output Range.

• Top and Bottom Gate Drivers Sink 2.5A Peak

• Adaptive Gate Driver Dead-time Control

• Wide Bandwidth Error Amplifier (4MHz)

• Programmable Soft-start

• Thermal Shutdown Protection

• TSSOP-16 or Thermally Enhanced WSON-16

Packages

DESCRIPTION

The LM25115 controller contains all of the features

necessary to implement multiple output power

converters utilizing the Secondary Side Post

Regulation (SSPR) technique. The SSPR technique

develops a highly efficient and well regulated auxiliary

output from the secondary side switching waveform of

an isolated power converter. Regulation of the

auxiliary output voltage is achieved by leading edge

pulse width modulation (PWM) of the main channel

duty cycle. Leading edge modulation is compatible

with either current mode or voltage mode control of

the main output. The LM25115 drives external high

side and low side NMOS power switches configured

as a synchronous buck regulator. A current sense

amplifier provides overload protection and operates

over a wide common mode input range. Additional features include a low dropout (LDO) bias regulator,

error amplifier, precision reference, adaptive dead

time control of the gate signals and thermal

shutdown.