NCP1381 Datasheet, PDF (1/26 Pages) ON Semiconductor – Low−Standby High Performance PWM Controller

NCP1381
Low−Standby High
Performance PWM
Controller
Housed in a SO−14 package, the NCP1381 includes everything
needed to build rugged and efficient Quasi−Resonant (QR) Switching
Power Supplies. When powered by a front−end Power Factor
Correction circuitry, the NCP1381 automatically disconnects the PFC
controller in low output loading conditions (with an adjustable level),
thus improving the standby power. This is particularly well suited for
medium to high power offline applications, e.g. notebook adapters.
When the current setpoint falls below a given value, e.g. the output
power demand diminishes, the IC automatically enters the so−called
skip cycle mode and provides excellent efficiency at light loads.
Because this occurs at an adjustable low peak current together with a
proprietary Soft−Skipt technique, no acoustic noise takes place. Skip
cycle also offers the ability to easily select the maximum switching
frequency at which foldback and standby take place.
The NCP1381 also features several efficient protection options like
a) a short−circuit / overload detection independent of the auxiliary
voltage b) an auto−recovery brown−out detection and c) an input to
externally latch the circuit in case of Overvoltage Protection or Over
Temperature Protection.
Features
• Current−Mode Quasi−Resonant Operation
• Adjustable Line Over Power Protection
• Extremely Low Startup Current of 15 mA Maximum
• Soft−Skip Cycle Capability at Adjustable Peak Currents
• Plateau Sensing Overvoltage
• Brown−Out Protection
• Maximum t_ON Limitation
• Overpower Protection by current Sense Offset
• Internal 5 ms Soft−Start Management
• Short−Circuit Protection Independent from Auxiliary Level
• External Latch Input Pin for an OTP Signal
• Go−To−Standby Signal for the PFC Front Stage
• True Frequency (t_ON + t_OFF) Clamp Circuit
• Low and Noiseless, No−Load Standby Power
• Internal Leading Edge Blanking
• +500 mA / −800 mA Peak Current Drive Capability
• 5 V / 10 mA Reference Voltage
• This is a Pb−Free Device
Typical Applications
• High Power AC/DC Adapters for Notebooks, etc
• Offline Battery Chargers
• Set−Top Boxes Power Supplies, TV, Monitors, etc
http://onsemi.com
HIGH PERFORMANCE QR
CONTROLLER FEATURING PFC
SHUTDOWN
14
1
MARKING
DIAGRAM
14
SOIC−14
D SUFFIX
CASE 751A
1
NCP1381G
AWLYWW
NCP1381G = Specific Device Code
A
= Assembly Location
WL
= Wafer Lot
Y
= Year
WW
= Work Week
G = Pb−Free Package
ADJ_GTS ₁
BO ₂
DMG ₃
Timer 4
Skip/OVP 5
FB 6
CS 7
14 nc
13 nc
12 ^Ref
11
GTS
10
V_CC
9 DRV
8 _GND
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 25 of this data sheet.
© Semiconductor Components Industries, LLC, 2006
1
July, 2006 − Rev. 3
Publication Order Number:
NCP1381/D