OB5269B
High Voltage Green Mode PWM Controller with Brownout
GENERAL DESCRIPTION
OB5269B is a highly integrated current mode
PWM control IC with high voltage start up,
optimized for high performance, low standby
power consumption and cost effective offline
flyback converter applications.
PWM switching frequency at normal operation is
internally fixed and is trimmed to a tight range. At
no load or light load condition, the IC operates in
extended ‘burst mode’ to minimize switching loss.
Very low standby power consumption and very
high conversion efficiency is thus achieved.
High voltage startup is implemented in OB5269B,
which features with short startup time and low
standby current.
OB5269B offers complete protection coverage
with auto-recovery including Cycle-by-Cycle
current limiting (OCP), over load protection (OLP),
brownout protection and VDD under voltage
lockout (UVLO). It also provides the protections
with latched shut down including over temperature
protection (OTP), and VDD over voltage protection.
Excellent EMI performance is achieved with On-
Bright proprietary frequency shuffling technique.
The tone energy at below 22KHZ is minimized to
avoid audio noise during operation.
OB5269B is offered in SOP8 package.
FEATURES
■ High Voltage Startup
■ Power on Soft Start Reducing MOSFET Vds
Stress
■ Frequency shuffling for EMI
■ Extended Burst Mode Control For Improved
Efficiency and Minimum Standby Power
■ Audio Noise Free Operation
■ Fixed 65KHZ Switching Frequency
■ Comprehensive Protection Coverage
o VDD Under Voltage Lockout with
Hysteresis (UVLO)
o Cycle-by-cycle over current protection
(OCP)
o Overload Protection (OLP) with auto-
recovery
o Brownout Protection with auto-recovery
o Over Temperature Protection (OTP) with
latch shut down
o VDD Over voltage Protection(OVP) with
latch shut down
■ Intelligent AC off Detect with X-cap discharge
function (On-Bright patent)
APPLICATIONS
Offline AC/DC flyback converter for
■ Battery Charger
■ Power Adaptor
■ Open-frame SMPS
TYPICAL APPLICATION
©On-Bright Electronics
Confidential
-1-
Preliminary Datasheet
OB_DOC_DS_5269B03
