General 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.

Features

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 LLP-16 packages