NCP1231 Datasheet, PDF (1/21 Pages) ON Semiconductor – Low−Standby Power High Performance PWM Controller

NCP1231
Low−Standby Power High
Performance PWM
Controller
The NCP1231 represents a major leap towards achieving low
standby power in medium−to−high power Switched−Mode Power
Supplies such as notebook adapters, off−line battery chargers and
consumer electronics equipment. Housed in SOIC−8 or PDIP−8, the
NCP1231 contains all needed control functionality to build a rugged
and efficient power supply. Among the unique features offered by the
NCP1231 is an event management scheme that can disable the
front−end PFC circuit during standby, thus reducing the no load power
consumption. The NCP1231 itself goes into cycle skipping at light
loads while limiting peak current (to 25% of nominal peak) so that no
acoustic noise is generated and while in the skip cycle mode.
The NCP1231 also features an internal latching function that can be
used for Overvoltage Protection (OVP). The latch is triggered when
the voltage on Pin 8 rises above 4.0 V. During an OVP condition, the
output drive pulses are immediately stopped and the NCP1231 stays in
the latched off condition until V_CC drops below 4.0 V (V_CCreset). In
addition, Pin 8 also serves as a Brown−Out input which provides the
necessary safety feature when the SMPS faces low mains situations.
Features
• Current−Mode Operation with Internal Ramp Compensation
• Extremely Low Startup Current of 30 mA Typical
• Skip−Cycle Capability at Low Peak Currents
• Adjustable Soft−Start
• Overvoltage and Brown−Out Protection
• Short−Circuit Protection Independent of Auxiliary Level
• Internal Frequency Dithering for Improved EMI Signature
• Go−To−Standby Signal for PFC Front Stage
• Extremely Low No−Load, Noiseless, Standby Power
• Internal Leading Edge Blanking
• +500 mA/−800 mA Peak Current Drive Capability
• Available in Three Frequency Options: 65 kHz, 100 kHz, and 133 kHz
• Direct Optocoupler Connection
• SPICE Models Available for TRANsient and AC Analysis
• Pb−Free Packages are Available
http://onsemi.com
MARKING
DIAGRAMS
8
SOIC−8
D SUFFIX
1
CASE 751
231Dx
y
ALYW
G
1
PDIP−8
P SUFFIX
CASE 626
8
1231Pzz
AWL
YYWWG
1
1
231Dxy
1231Pzz
A
L, WL
Y, YY
W, WW
G or G
= Device Code
x = 1 or 6
y = 0 or 3
= Device Code
zz = 65, 100 or 133
= Assembly Location
= Wafer Lot
= Year
= Work Week
= Pb−Free Package
PIN CONNECTIONS
1
PFC_V_CC
FB
CS
GND
8
BO/OVP
SS
V_CC
DRV
Typical Applications
• High Power AC−DC Adapters for Notebooks, etc.
• Offline Battery Chargers
• Set−Top Boxes Power Supplies, TV, Monitors, etc.
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 19 of this data sheet.
© Semiconductor Components Industries, LLC, 2006
1
July, 2006 − Rev. 4
Publication Order Number:
NCP1231/D