ON Semiconductor NCP4354BDR2G

Description
The NCP4353/4 is a secondary side SMPS controller designed for applications requiring extremely low no-load power consumption. It detects "no load" conditions and enters the power supply into a low consumption OFF mode. During OFF mode, the primary side controller is turned off and energy is provided by the output capacitors, eliminating the power consumption required for regulation. The output voltage relaxes and decreases to an adjustable level. Once more energy is required, the NCP4353/4 automatically restarts the primary side controller.
The NCP4353/4 controls the primary side controller with an "Active OFF" signal, driving optocoupler current during OFF mode to pull-down the FB pin of the primary controller. During normal power supply operation, it provides integrated voltage feedback regulation, replacing the need for a shunt regulator. The A versions include a current regulation loop in addition to voltage regulation. Feedback control and ON/OFF signal can be provided with only one optocoupler.
The NCP4354 includes a LED driver pin implemented with an open-drain MOSFET driven by a 1 kHz square wave with a 12.5% duty cycle when the primary side is in regulation for indication purposes.

Features
Operating Input Voltage Range: 2.5 V to 36.0 V
Supply Current: 100 μA
±0.5% Reference Voltage Accuracy (T) = 25°C
Constant Voltage and Constant Current (A versions) Control Loop
Indication LED PWM Modulated Driver (NCP4354x)
Designed for use with NCP1246 Fixed Frequency PWM Controller
Pb-Free, Halogen Free/BFR Free, and RoHS Compliant

Applications
Offline Adapters for Notebooks, Game Stations, and Printers
High Power AC-DC Converters for TVs, Set-Top Boxes, Monitors, etc.