OB233F
High Performance Current Mode PWM Power Switch
GENERAL DESCRIPTION
OB233F combines a dedicated current mode
PWM controller with a high voltage power
MOSFET. It is optimized for high performance, low
standby power, and cost effective off-line flyback
converter applications.
OB233F offers complete protection coverage with
automatic recovery feature including Cycle-by-
Cycle current limiting (OCP), over load protection
(OLP), over temperature protection (OTP), over
voltage protection and VDD under voltage lockout
(UVLO). Excellent EMI performance is achieved
with On-Bright proprietary frequency shuffling
technique together with soft switching control at
the totem pole gate drive output.
The tone energy at below 20KHZ is minimized in
the design and audio noise is eliminated during
operation.
OB233F is offered in DIP7 package.
APPLICATIONS
Offline AC/DC flyback converter for
■ AC/DC adapter
■ PDA power supplies
■ Digital cameras and camcorder adapter
■ VCR, SVR, STB, DVD&DVCD Player SMPS
■ Set-top box power
■ Auxiliary power supply for PC and Server
■ Open-frame SMPS
TYPICAL APPLICATION
FEATURES
■ Standby power lower than 100mW at
universal AC input
■ Power on soft start reducing Power 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 (typical) switching frequency
■ Internal synchronized slope compensation
■ Low VDD startup current and low operating
current
■ Leading edge blanking on current sense input
■ Comprehensive protection coverage
o VDD under voltage lockout with hysteresis
(UVLO)
o Over temperature protection (OTP) with
auto- recovery
o On-Bright proprietary line input
compensated
o Cycle-by-Cycle over-current threshold
setting for constant output power limiting
over universal input voltage range.
o Accurate overload protection (OLP).
o Over voltage protection(OVP)
o Secondary rectifier short protection
Output Power Table
Product
230VAC±15%
Adapter1
85-265VAC
Adapter1
OB233F
23W
18W
Notes: 1. Maximum practical continuous power in an adapter design with sufficient drain pattern as a heat sink, at 40℃ ambient.
©On-Bright Electronics
Confidential
-1-
Preliminary Datasheet
OB_DOC_DS_233F01
