http://www.datasheet4u.com

900,000+ datasheet pdf search and download

Datasheet4U offers most rated semiconductors data sheet pdf




  ON Semiconductor Electronic Components Datasheet  

NCP1248 Datasheet

Fixed Frequency Current Mode Controller

No Preview Available !

NCP1248 pdf
NCP1248
Fixed Frequency Current
Mode Controller for Flyback
Converters
The NCP1248 is a new fixed-frequency current-mode controller
featuring the Dynamic Self-Supply. This function greatly simplifies
http://onsemi.com
the design of the auxiliary supply and the VCC capacitor by activating
the internal startup current source to supply the controller during
start-up, transients, latch, stand-by etc. This device contains a special
HV detector which detect the application unplug from the AC input
SOIC−7
line and triggers the X2 discharge current. This HV structure allows
CASE 751U
the brown-out detection as well.
It features a timer-based fault detection that ensures the detection of
MARKING DIAGRAM
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
8
48Axxx
ALYWX
G
1
excellent candidate for the robust power supply designs.
A dedicated Off mode allows to reach the extremely low no load
input power consumption via “sleeping” whole device and thus
minimize the power consumption of the control circuitry.
Features
Fixed-Frequency Current-Mode Operation using 65 kHz/100 kHz
48Axxx = Specific Device Code
xxx = 065 for 65 kHz
= 100 for 100 kHz
A = Assembly Location
L = Wafer Lot
Y = Year
W = Work Week
G = Pb-Free Package
Switching Frequency
Frequency Foldback then Skip Mode for Maximized Performance
PIN CONNECTIONS
in Light Load and Standby Conditions
Timer-Based Overload Protection with Latched (Option A)
Operation
High-voltage Current Source with Brown-Out Detection and
Dynamic Self-Supply, Simplifying the Design of the VCC
Circuitry
Frequency Modulation for Softened EMI Signature
Latch
FB
CS
GND
1
2
3
4
8
HV
6
VCC
5
DRV
(Top View)
Adjustable Overpower Protection Dependant on the Bulk Voltage
Latch-off Input Combined with the Overpower Protection
Sensing Input
ORDERING INFORMATION
See detailed ordering and shipping information on page 35 of
this data sheet.
VCC Operation up to 28 V, With Overvoltage Detection
500/800 mA Source/Sink Drive Peak Current Capability
Typical Applications
10 ms Soft-Start
AC-DC Adapters for Notebooks, LCD, and Printers
Internal Thermal Shutdown
Offline Battery Chargers
No-Load Standby Power < 30 mW
Consumer Electronic Power Supplies
X2 Capacitor in EMI Filter Discharging Feature
Auxiliary/Housekeeping Power Supplies
These Devices are Pb-Free and Halogen Free/BFR Free
Offline Adapters for Notebooks
© Semiconductor Components Industries, LLC, 2014
December, 2014 − Rev. 0
1
Publication Order Number:
NCP1248/D


  ON Semiconductor Electronic Components Datasheet  

NCP1248 Datasheet

Fixed Frequency Current Mode Controller

No Preview Available !

NCP1248 pdf
NCP1248
TYPICAL APPLICATION EXAMPLE
1 L2 2
ac input
CX2
34
1 L1 2
CX1
34
CCLAMP
D9 RHV
D8
D10
C4
NTC
GND GND
GND
IC1
1 LATCH HV 8
2 FB
3 CS VCC 6
4 GND DRV 5
GND NCP1248
GND
D3
C1
TR
1
3
2
5
4
GND Q1
6
GND
ROPP
D1 dc output
COUT
GND
GND
C2
OK1
41
32
PC817 IC2
C3
GND GND NCP431
GND GND
Figure 1. Flyback Converter Application Using the NCP1248
PIN FUNCTION DESCRIPTION
Pin No Pin Name
Function
1 LATCH
Latch−Off Input
2 FB Feedback + Shutdown pin
3 CS
Current Sense
4 GND
5 DRV
6 VCC
Drive output
VCC input
8 HV
High−voltage pin
Pin Description
Pull the pin up or down to latch−off the controller. An internal current source
allows the direct connection of an NTC for over temperature detection.
An optocoupler collector to ground controls the output regulation. The part
goes to the low consumption Off mode if the FB input pin is pulled to GND.
This Input senses the Primary Current for current−mode operation, and
offers an overpower compensation adjustment.
The controller ground
Drives external MOSFET
This supply pin accepts up to 28 Vdc, with overvoltage detection. The pin is
connected to an external auxiliary voltage. It is not allowed to connect
another circuit to this pin to keep low input power consumption.
Connects to the rectified AC line to perform the functions of Start−up
Current Source, Self−Supply, brown−out detection and X2 capacitor
discharge function and the HV sensing for the overpower protection
purposes. It is not allowed to connect this pin to DC voltage.
http://onsemi.com
2


Part Number NCP1248
Description Fixed Frequency Current Mode Controller
Maker ON Semiconductor
Total Page 30 Pages
PDF Download
NCP1248 pdf
NCP1248 Datasheet PDF
[partsNo] view html
View PDF for Mobile








Similar Datasheet

1 NCP1240 Fixed Frequency Current Mode Controller ON Semiconductor
ON Semiconductor
NCP1240 pdf
2 NCP1244 Fixed Frequency Current Mode Controller ON Semiconductor
ON Semiconductor
NCP1244 pdf
3 NCP1246 Fixed Frequency Current Mode Controller ON Semiconductor
ON Semiconductor
NCP1246 pdf
4 NCP1247 Fixed Frequency Current Mode Controller ON Semiconductor
ON Semiconductor
NCP1247 pdf
5 NCP1248 Fixed Frequency Current Mode Controller ON Semiconductor
ON Semiconductor
NCP1248 pdf
6 NCP1249C High-Voltage Current-Mode PWM Controller Featuring Peak Power Excursion and Self-Relaxing Off Mode ON Semiconductor
ON Semiconductor
NCP1249C pdf
7 NCP1249D High-Voltage Current-Mode PWM Controller Featuring Peak Power Excursion and Self-Relaxing Off Mode ON Semiconductor
ON Semiconductor
NCP1249D pdf





Part Number Start With

0    1    2    3    4    5    6    7    8    9    A    B    C    D    E    F    G    H    I    J    K    L    M    N    O    P    Q    R    S    T    U    V    W    X    Y    Z

Site map

Webmaste! click here

Contact us

Buy Components

Privacy Policy