The NCP4303A/B is a full featured controller and driver tailored to

control synchronous rectification circuitry in switch mode power

supplies. Thanks to its versatility, it can be used in various topologies

such as flyback, forward and Half Bridge Resonant LLC.

The combination of externally adjustable minimum on and off times

helps to fight the ringing induced by the PCB layout and other

parasitic elements. Therefore, a reliable and noise less operation of the

SR system is insured.

The extremely low turn off delay time, high sink current capability

of the driver and automatic package parasitic inductance

compensation system allow to maximize synchronous rectification

MOSFET conduction time that enables further increase of SMPS

efficiency.

Finally, a wide operating VCC range combined with two versions of

driver voltage clamp eases implementation of the SR system in 24 V

output applications.

Features

• Self-Contained Control of Synchronous Rectifier in CCM, DCM, and

QR Flyback Applications

• Precise True Secondary Zero Current Detection with Adjustable

Threshold

• Automatic Parasitic Inductance Compensation Input

• Typically 40 ns Turn off Delay from Current Sense Input to Driver

• Zero Current Detection Pin Capability up to 200 V

• Optional Ultrafast Trigger Interface for Further Improved

Performance in Applications that Work in Deep CCM

• Disable Input to Enter Standby or Low Consumption Mode

• Adjustable Minimum On Time Independent of VCC Level

• Adjustable Minimum Off Time Independent of VCC Level

• 5 A/2.5 A Peak Current Sink/Source Drive Capability

• Operating Voltage Range up to 30 V

• Gate Drive Clamp of Either 12 V (NCP4303A) or 6 V (NCP4303B)

• Low Startup and Standby Current Consumption

• Maximum Frequency of Operation up to 500 kHz

• SOIC−8 Package

• These are Pb-Free Devices

Typical Applications

• Notebook Adapters

• High Power Density AC/DC Power Supplies

• Gaming Consoles

• All SMPS with High Efficiency Requirements