|
NCP1240 Datasheet, PDF (1/45 Pages) ON Semiconductor – Fixed Frequency Current Mode Controller | |||
|
NCP1240
Fixed Frequency Current
Mode Controller for Flyback
Converters
The NCP1240 is a new fixedâfrequency currentâmode controller
featuring the Dynamic SelfâSupply. This function greatly simplifies
the design of the auxiliary supply and the VCC capacitor by activating
the internal startup current source to supply the controller during
startâup, transients, latch, standâby etc. This device contains a special
HV detector which detect the application unplug from the AC input
line and triggers the X2 discharge current. This HV structure allows
the brownâout detection as well.
It features a timerâbased fault detection that ensures the detection of
overload and an adjustable compensation to help keep the maximum
power independent of the input voltage.
Due to frequency foldback, the controller exhibits excellent
efficiency in light load condition while still achieving very low
standby power consumption. Internal frequency jittering, ramp
compensation, and a versatile latch input make this controller an
excellent candidate for the robust power supply designs.
A dedicated Off mode allows to reach the extremely low no load
input power consumption via âsleepingâ whole device and thus
minimize the power consumption of the control circuitry.
www.onsemi.com
MARKING
DIAGRAM
SOICâ7
CASE 751U
8
40Xfff
ALYWX
G
1
40Xfff = Specific Device Code
X = A, B, E or F
fff = 065 or 100
A = Assembly Location
L = Wafer Lot
Y = Year
W = Work Week
G
= PbâFree Package
PIN CONNECTIONS
Features
⢠FixedâFrequency CurrentâMode Operation (65 kHz and 100 kHz
frequency options)
⢠Frequency Foldback then Skip Mode for Maximized Performance in
Light Load and Standby Conditions
Latch 1
FB 2
CS 3
GND 4
8 HV
6 VCC
5 DRV
⢠TimerâBased Overload Protection with Latched (Options A and E) or
(Top View)
AutoâRecovery (Options B and F) Operation
⢠Highâvoltage Current Source with BrownâOut Detection and
Dynamic SelfâSupply, Simplifying the Design of the VCC Circuitry
⢠Frequency Modulation for Softened EMI Signature
ORDERING INFORMATION
See detailed ordering and shipping information on page 44 of
this data sheet.
⢠Adjustable Overpower Protection Dependant on the Bulk Voltage
⢠Latchâoff Input Combined with the Overpower Protection Sensing
Input
⢠VCC Operation up to 28 V, With Overvoltage Detection
⢠500/800 mA Source/Sink Drive Peak Current
Capability
⢠10 ms SoftâStart
⢠Internal Thermal Shutdown
⢠NoâLoad Standby Power < 30 mW
⢠X2 Capacitor in EMI Filter Discharging Feature
Typical Applications
⢠ACâDC Adapters for Notebooks, LCD, and Printers
⢠Offline Battery Chargers
⢠Consumer Electronic Power Supplies
⢠Auxiliary/Housekeeping Power Supplies
⢠Offline Adapters for Notebooks
⢠These Devices are PbâFree and Halogen Free/BFR Free
© Semiconductor Components Industries, LLC, 2015
1
July, 2015 â Rev. 1
Publication Order Number:
NCP1240/D
|
▷ |