© Semiconductor Components Industries, LLC, 2015
April, 2015 − Rev. 4
1 Publication Order Number:
NCP4353/D
NCP4353, NCP4354
Secondary Side SMPS OFF
Mode Controller for Low
Standby Power
The NCP4353/4 is a secondary side SMPS controller designed for
use in applications which require extremely low no load power
consumption. The device is capable of detecting “no load” conditions
and entering the power supply into a low consumption OFF mode.
During OFF mode, the primary side controller is turned off and energy
is provided by the output capacitors thus eliminating the power
consumption required to maintain regulation. During OFF mode, the
output voltage relaxes and is allowed to decrease to an adjustable
level. Once more energy is required, the NCP4353/4 automatically
restarts the primary side controller. The NCP4353/4 controls the
primary side controller with an “Active OFF” signal, meaning that it
drives optocoupler current during OFF mode to pull−down the FB pin
of the primary controller.
During normal power supply operation, the NCP4353/4 provides
integrated voltage feedback regulation, replacing the need for a shunt
regulator. The A versions include a current regulation loop in addition
to voltage regulation. Feedback control as well as ON/OFF signal can
be provided with only one optocoupler.
The NCP4354 includes a LED driver pin implemented with an open
drain MOSFET driven by a 1 kHz square wave with a 12.5% duty
cycle when primary side is in regulation for indication purpose.
The NCP4353 is available in TSOP−6 package while the NCP4354
is available in SOIC−8 package.
Features
• Operating Input Voltage Range: 2.5 V to 36.0 V
• Supply Current < 100 mA
• ±0.5% Reference Voltage Accuracy (T
J
= 25°C)
• Constant Voltage and Constant Current (A versions) Control Loop
• Indication LED PWM Modulated Driver (NCP4354x)
• Designed for use with NCP1246 Fixed Frequency PWM Controller
• These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS
Compliant
Typical Applications
• Offline Adapters for Notebooks, Game Stations and Printers
• High Power AC−DC Converters for TVs, Set−Top Boxes, Monitors, etc.
DEVICE OPTIONS
NCP4353A NCP4353B NCP4354A NCP4354B
Adjustable
V
min
No Yes Yes Yes
Current
Regulation
Yes No Yes No
LED Driver No No Yes Yes
Package TSOP−6 TSOP−6 SOIC−8 SOIC−8
www.onsemi.com
MARKING
DIAGRAMS
SOIC−8
CASE 751
1
8
XXXXX
ALYW G
G
1
8
1
XXXAYWG
G
1
TSSOP−6
CASE 318G
A = Assembly Location
L = Wafer Lot
Y = Year
W = Work Week
G = Pb−Free Package
See detailed ordering, marking and shipping information in the
package dimensions section on page 15 of this data sheet.
ORDERING INFORMATION
(Note: Microdot may be in either location)
