描述 Description

The LM25115A controller contains all of the features necessary to produce multiple tracking outputs using 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. LM25115A can be also used as a standalone DC/DC synchronous buck controller (Refer tosection). 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 LM25115A 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.

特性 Features

? Power-up/Power-down Tracking
? Self-synchronization to Main Channel Output
? Leading Edge Pulse Width Modulation
? Valley Current Mode Control
? Standalone DC/DC Synchronous Buck Mode
? 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 package