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WS3252 Datasheet, PDF (1/8 Pages) Shenzhen Winsemi Microelectronics Co., Ltd – WS3252 High Precision CC/CV Primary-Side PWM Controller | |||
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WS3252
WS3252 High Precision CC/CV Primary-Side PWM Controller
Features
â 5uA ultra-low startup current
â 2mA Low operating current
â ±5% Constant Voltage Regulation at Universal AC input
â Primary-side Sensing and Regulation Without TL431
and Opto-coupler
â Programmable CV and CC Regulation
â Built-in Primary winding inductance compensation
â Programmable cable drop compensation
â Built-in soft start
â Built-in Leading-edge blanking
â Cycle by cycle over current protection (OCP)
â VCC over voltage clamp & under voltage lockout( UVLO)
â Maximum Gate output voltage clamped at 12V
â Frequency jittering
General Description
WS3252 is a high-integrated offline PWM controller,
optemized for high poformance low power AC/DC charger
and adapter adapter application.
WS3252 operates in primary-side sensing and regulation.
Consequently, opto-coupler and TL431 could be
eliminated, thus reduce the cost. It can achieve ± 5%
constant voltage precision in full input voltage range.
CC/CV Control as shown in fig.1.In CC Control, the current
and output power setting can be adjusted externally by the
sense resistor Rs at CS pin. In CV control, multi-mode
operations are utilized to achieve high performance and
high efficiency. In addition, good load regulation is
achieved by the built-in cable drop compensation. Device
operates in PFM in CC mode as well at large load
condition and it operates in PWM with frequency reduction
at light/medium load.
Vo
Applications
Low power AC/DC offline SMPS for
â Cell Phone Charger
â Digital Cameras Charger
â Small Power Adapter
â Auxiliary Power for PC, TV etc.
â Linear Regulator/RCC Replacement
Typical Application Circuit
5%
Io
Icc
WS3252 offers power on soft start control and protection
coverage with auto-recovery features including
Cycle-by-Cycle current limiting, VCC OVP,VCC clamp and
UVLO. The gate-driven output is clamped to maximum 12V
to protect the internal MOSFET. Excellent EMI performance
is achieved by using the soft-switching and frequency jittering
at the totem-pole-gate-drive output. The WS3252 is the ideal
substitute of the linear power supply or the RCC-mod e
power, for a better performance of the whole switch power
system and a lower cost.
WS3252 is available in SOT23-6 package.
Rev.A Sep.2011
Copyright@Winsemi Microelectronics Co., Ltd., All right reserved.
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