© Semiconductor Components Industries, LLC, 2015
April, 2015 − Rev. 9
1 Publication Order Number:
NCP1217/D
NCP1217, NCP1217A
Enhanced PWM Current-Mode
Controller for High-Power
Universal Off-Line Supplies
Housed in an SO−8 or PDIP−7 package, the NCP1217 represents
the enhanced version of the NCP1203−based controllers. Due to its
high drive capability, NCP1217 drives large gate−charge MOSFETs,
which together with internal ramp compensation and built−in
overvoltage protection, ease the design of modern AC/DC adapters.
NCP1217 offers a true alternative to UC384X−based designs.
With an internal structure operating at different fixed frequencies
(65–100–133 kHz), the controller features a high−voltage startup FET,
which ensures a clean and loss less startup sequence. Its current−mode
control topology provides an excellent input audio−susceptibility and
inherent pulse−by−pulse control. Internal ramp compensation easily
prevents subharmonic oscillations from taking place in continuous
conduction mode designs.
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 a user adjustable low peak current, no acoustic
noise takes place.
The NCP1217 features two efficient protective circuitries: 1) In
presence of an overcurrent condition, the output pulses are disabled
and the device enters a safe burst mode, trying to restart. Once the
default has gone, the device auto−recovers. 2) If an external signal
(e.g. a temperature sensor) pulls Pin 1 above 3.2 V, output pulses are
immediately stopped and the NCP1217 stays latched in this position.
Reset occurs when the V
CC
collapses to ground, e.g. the user unplugs
the power supply.
Features
• Current−Mode with Adjustable Skip−Cycle Capability
• Built−in Internal Ramp Compensation
• Auto−Recovery Internal Output Short−Circuit Protection
• Internal 1.0 ms Soft−Start (NCP1217A Only)
• Limited Duty−Cycle to 50% (NCP1217A Only)
• Full Latchoff if Adjustment Pin is Brought High
• Extremely Low No−Load Standby Power
• Internal Temperature Shutdown
• 500 mA Peak Current Capability
• Fixed Frequency Versions at 65 kHz, 100 kHz and 133 kHz
• Direct Optocoupler Connection
• Internal Leading Edge Blanking
• SPICE Models Available for TRANsient and AC Analysis
• These are Pb−Free Devices
Typical Applications
• High Power AC/DC Converters for TVs, Set−Top Boxes, etc.
• Offline Adapters for Notebooks
• Telecom DC−DC Converters
• All Power Supplies
MARKING
DIAGRAMS
XXXXXX = Specific Device Code
A = Assembly Location
L, WL = Wafer Lot
Y, YY = Year
W, WW = Work Week
G or G = Pb−Free Package
www.onsemi.com
PDIP−7
P SUFFIX
CASE 626B
1
8
SOIC−8
D SUFFIX
CASE 751
18
5
3
4
(Top View)
Adj
CS
HV
PIN CONNECTIONS
7
6
2
NC
FB
GND
Drv
V
CC
See detailed ordering and shipping information in the ordering
information section on page 17 of this data sheet.
ORDERING INFORMATION
XXXXX
ALYW
G
1
8
1
8
XXXXXXXXX
AWL
YYWWG
1
See detailed device marking information in the ordering
information section on page 17 of this data sheet.
DEVICE MARKING INFORMATION
