PWM Controller. OB2279 Datasheet

OB2279 Controller. Datasheet pdf. Equivalent

Part OB2279
Description Current Mode PWM Controller
Feature RESLEEPRAILSCEAELAODSNNEFTIO:oDD2EOA7NP9NT0IDO0AT6L8COPY OB2279 Current Mode PWM ControllerFreq Shu.
Manufacture On-Bright
Total Page 13 Pages
Datasheet
Download OB2279 Datasheet



OB2279
OB2279
Current Mode PWM ControllerFreq Shuffling with Latch Shutdown
GENERAL DESCRIPTION
OB2279 is a highly integrated current mode PWM
control IC optimized for high performance, low
standby power and cost effective offline flyback
converter applications.
PWM switching frequency at normal operation is
externally programmable and trimmed to tight range.
At no load or light load condition, the IC operates in
extended ‘burst mode’ to minimize switching loss.
Lower standby power and higher conversion
efficiency is thus achieved.
VDD low startup current and low operating current
contribute to a reliable power on startup design with
OB2279. A large value resistor could thus be used in
the startup circuit for reduced power loss.
The internal slope compensation improves system
large signal stability and reduces the possible sub-
harmonic oscillation at high PWM duty cycle output.
Leading-edge blanking on current sense input
removes the signal glitch due to snubber circuit diode
reverse recovery and greatly reduces the external
component count and system cost in the design.
OB2279 offers comprehensive protection coverage
including Cycle-by-Cycle current limiting(OCP),
VDD Under Voltage Lockout(UVLO), VDD Over
Voltage Protection(OVP), VDD Clamp, Gate Clamp,
Over Load protection(OLP) and Over Temperature
protection (OTP), etc.
Different latch shutdown options are offered on
OB2279 in different device version. V version has
OVP Latch shutdown. T version supports both OVP
and OTP latch shutdown. L version provides all OVP,
OTP and OLP latch shutdown control.
Excellent EMI performance is achieved with On-
Bright proprietary frequency shuffling technique
together with soft switching control at the totem pole
gate drive output.
OB2279 is offered in SOP-8 and DIP-8 packages.
FEATURES
On-Bright Proprietary Frequency Shuffling
Technology for Improved EMI Performance
Power On Soft Start
Extended Burst Mode Control For Improved
Efficiency and Minimum Standby Power Design
Audio Noise Free Operation
External Programmable PWM Switching
Frequency
Internal Synchronized Slope Compensation
Low VIN/VDD Startup Current(3uA) and Low
Operating Current (2.3mA)
Leading Edge Blanking on Current Sense Input
Complete Protection Coverage with selective
protections for Latch Shutdown
o VDD Over Voltage Protection(OVP) – Latch
Shutdown
o Over Temperature Protection(OTP) – Auto
recovery or Latch Shutdown
o Over Load Protection. (OLP) – Auto recovery
or Latch Shutdown
o VDD Under Voltage Lockout with Hysteresis
(UVLO)
o Gate Output Voltage Clamp (16.5V)
o Built-in OCP Compensation to Achieve
Minimum OPP Variation over Universal AC
Input Range.
APPLICATIONS
Offline AC/DC flyback converter for
Adaptor
Notebook Adaptor
LCD Monitor/TV/PC/Set-Top Box Power
Supplies
Open-frame SMPS
Printer Power
TYPICAL APPLICATION
©On-Bright Electronics
-1-
Confidential
OB_DOC_DS_79A1



OB2279
OB2279
Current Mode PWM ControllerFreq Shuffling with Latch Shutdown
GENERAL INFORMATION
Pin Configuration
The pin map of OB2279 in DIP8 and SOP8 package
is shown as below.
OB2279CP-L
SOP8, tube package, L
version with OVP/OTP/OLP
latch
OB2279CPA-L
SOP8, taping package, L
version with OVP/OTP/OLP
latch
Note: All Devices are offered in Pb-free Package if not otherwise
noted.
Package Dissipation Rating
Package
DIP8
SOP8
RθJA (°C/W)
90
150
Ordering Information
Part Number
OB2279AP-V
Description
DIP8, tube package, V
version with OVP Latch
OB2279AP-T
DIP8, tube package, T
version with OVP/OTP latch
OB2279AP-L
DIP8, tube package, L
version with OVP/OTP/OLP
latch
OB2279CP-V
SOP8, tube package, V
version with OVP latch
OB2279CPA-V SOP8, taping package, V
version with OVP latch
OB2279CP-T
SOP8, tube package, T
version with OVP/OTP latch
OB2279CPA-T SOP8, taping package, T
version with OVP/OTP latch
Absolute Maximum Ratings
Parameter
VDD Clamp Voltage (Vclamp)
VDD Clamp Continuous
Current
VIN / VDD Input Voltage
FB Input Voltage
Sense Input Voltage
RT Input Voltage
RI Input Voltage
Min/Max Operating Junction
Temperature TJ
Min/Max Storage Temperature
Tstg
Lead Temperature (Soldering,
10 seconds)
Value
35 V
10 mA
-0.3V to Vclamp
-0.3 to 7V
-0.3 to 7V
-0.3 to 7V
-0.3 to 7V
-20 to 150 oC
-55 to 150 oC
260 oC
Note: Stresses beyond those listed under “absolute maximum
ratings” may cause permanent damage to the device. These are
stress ratings only, functional operation of the device at these or
any other conditions beyond those indicated under
“recommended operating conditions” is not implied. Exposure to
absolute maximum-rated conditions for extended periods may
affect device reliability.
©On-Bright Electronics
-2-
Confidential
OB_DOC_DS_79A1





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