OB2273 High Performance Current Mode PWM Controller
Marking code: SOT23-6
273J05 , 273J26 , 73K02A , 73I27p , 73127p
73xxxx
73****
-73I12p, 73I15p, 73I16p, 73I17p, 73I18p, 73I19p, 73I24p, 73I25p, 73I26p SOT23-6
-73112p, 73115p, 73116p, 73117p, 73118p, 73119p, 73124p, 73125p, 73I26p SOT23-6
-73J12p, 73J15p, 73J16p, 73J17p, 73J18p, 73J19p, 73J24p, 73J25p, 73J26p SOT23-6
-73K12p, 73K15p, 73K16p, 73K17p, 73K18p, 73K19p, 73K24p, 73K25p, 73K26p SOT23-6
-73F05p
GENERAL DESCRIPTION
OB2273 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 internally fixed and is 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 and low
standby design with OB2273.
OB2273 offers complete protection coverage with auto-recovery including Cycle-by-Cycle current
limiting (OCP), over load protection (OLP), and VDD under voltage lockout (UVLO). It also
provides the protections with latched shut down including over temperature protection (OTP), and
over voltage (fixed or adjustable) protection (OVP). Excellent EMI performance is achieved with OnBright proprietary frequency shuffling technique. The tone energy at below 20KHZ is minimized in
the design and audio noise is eliminated during operation.
OB2273 is offered in SOT23-6 package.
FATURES
- Power on Soft Start Reducing MOSFET Vds Stress
- Frequency shuffling for EMI
- Extended Burst Mode Control For Improved Efficiency and Minimum Standby Power Design
- 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 threshold setting for constant output power limiting over universal input voltage range
o Overload Protection (OLP) with auto recovery
o Over Temperature Protection (OTP) with latch shut down
o VDD Over voltage Protection (OVP) with latch shut down
o Adjustable OVP Through external Zener
APPLICATIONSOffline AC/DC flyback converter for
- Battery Charger
- Power Adaptor
- Set-Top Box Power Supplies
- Open-frame SMPS