
Semiconductor Components Industries, LLC, 2004
July, 2004 Rev. 3
1
Publication Order Number:
NCP1217/D
NCP1217, NCP1217A
Enhanced PWM CurrentMode
Controller for HighPower
Universal OffLine Supplies
Housed in an SO8 or PDIP7 package, the NCP1217 represents
the enhanced version of the NCP1203based controllers. Thanks to its
high drive capability, NCP1217 drives large gatecharge MOSFETs,
which together with internal ramp compensation and builtin
overvoltage protection, ease the design of modern AC/DC adapters.
NCP1217 offers a true alternative to UC384Xbased designs.
With an internal structure operating at different fixed frequencies
(65–100–133 kHz), the controller features a highvoltage startup FET,
which ensures a clean and loss less startup sequence. Its currentmode
control topology provides an excellent input audiosusceptibility and
inherent pulsebypulse 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 socalled
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 autorecovers. 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
CurrentMode with Adjustable SkipCycle Capability
Builtin Internal Ramp Compensation
AutoRecovery Internal Output ShortCircuit Protection
Internal 1.0 ms SoftStart (A Version Only)
Limited DutyCycle to 50% (A Version Only)
Full Latchoff if Adjustment Pin is Brought High
Extremely Low NoLoad 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
PbFree Packages are Available
Typical Applications
High Power AC/DC Converters for TVs, SetTop Boxes, etc.
Offline Adapters for Notebooks
Telecom DCDC Converters
All Power Supplies
PDIP7
P SUFFIX
CASE 626B
1
8
1
8
SO8
D SUFFIX
CASE 751
1
8
5
3
4
(Top View)
Adj
CS
HV
PIN CONNECTIONS
7
6
2
NC
FB
Gnd
Drv
V
CC
MARKING
DIAGRAMS
See detailed ordering and shipping information in the ordering
information section on page 16 of this data sheet.
ORDERING INFORMATION
XXXX
A
WL, L
YY, Y
WW, W = Work Week
= Specific Device Code*
= Assembly Location
= Wafer Lot
= Year
http://onsemi.com
17XXX
ALYW
1
8
P1217XXXX
AWL
YYWW
1
MINIATURE PWM
CONTROLLER FOR HIGH
POWER AC/DC WALL
ADAPTERS AND OFFLINE
BATTERY CHARGERS
See detailed device marking information in the ordering
information section on page 16 of this data sheet.
*DEVICE MARKING INFORMATION