1FEATURES

2• Self-Synchronization to Main Channel Output

• Standalone DC/DC Synchronous Buck Mode

• Leading Edge Pulse Width Modulation

• Voltage-Mode Control with Current Injection

and Input Line Feed-Forward

• Operates from AC or DC Input up to 75V

• 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 LM5115 is a versatile switching regulator

controller. It has two main application configurations.

The first is utilizing the Secondary Side Post

Regulation (SSPR) technique to implement multiple

output power converters. In the second configuration,

it can be used as a standalone synchronous buck

controller (Please see Standalone DC/DC

Synchronous Buck Mode for more details). 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 LM5115 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.