© Semiconductor Components Industries, LLC, 2016
February, 2017 − Rev. 1
1 Publication Order Number:
NCP4308/D
NCP4308
Synchronous Rectifier
Controller
The NCP4308 is a synchronous rectifier controller for switch mode
power supplies. The controller enables high efficiency designs for
flyback, quasi resonant flyback and LLC topologies.
Externally adjustable minimum off−time and on−time blanking
periods provides flexibility to drive various MOSFET package types
and PCB layout. A reliable and noise less operation of the SR system is
insured due to the Self Synchronization feature. The NCP4308 also
utilizes Kelvin connection of the driver to the MOSFET to achieve high
efficiency operation at full load.
The precise turn−off threshold, extremely low turn−off delay time
and high sink current capability of the driver allow the maximum
synchronous rectification MOSFET conduction time. The high
accuracy driver and 5 V gate clamp make it ideally suited for directly
driving GaN devices.
Features
• Self−Contained Control of Synchronous Rectifier in CCM, DCM and
QR for Flyback or LLC Applications
• Precise True Secondary Zero Current Detection
• Rugged Current Sense Pin (up to 150 V)
• Adjustable Minimum ON−Time
• Adjustable Minimum OFF-Time with Ringing Detection
• Adjustable Maximum ON−Time for CCM Controlling of Primary
QR Controller
• Improved Robust Self Synchronization Capability
• 8 A / 4 A Peak Current Sink / Source Drive Capability
• Operating Voltage Range up to V
CC
= 35 V
• GaN Transistor Driving Capability (options A and C)
• Low Startup Current Consumption
• Maximum Operation Frequency up to 1 MHz
• SOIC-8, DFN−8 (4x4) and WDFN8 (2x2) Packages
• These are Pb−Free Devices
Typical Applications
• Notebook Adapters
• High Power Density AC/DC Power Supplies (Cell Phone Chargers)
• LCD TVs
• All SMPS with High Efficiency Requirements
SOIC−8
D SUFFIX
CASE 751
MARKING
DIAGRAMS
4308x = Specific Device Code
x = A, B, C, D or Q
Ex = Specific Device Code
x = A or D
A = Assembly Location
L = Wafer Lot
Y = Year
W = Work Week
M = Date Code
G = Pb−Free Package
1
8
NCP4308x
ALYW G
G
1
8
(Note: Microdot may be in either location)
4308x
ALYWG
G
1
DFN8
MN SUFFIX
CASE 488AF
www.onsemi.com
See detailed ordering and shipping information on page 26 o
this data sheet.
ORDERING INFORMATION
WDFN8
MT SUFFIX
CASE 511AT
ExMG
G
1
