WS3252

Applications
Low power AC/DC offline SMPS for
Cell Phone Charger
Digital Cameras Charger
Small Power Adapter
Auxiliary Power for PC, TV etc.
Linear Regulator/RCC Replacement

Features

5uA ultra-low startup current

2mA Low operating current

±5% Constant Voltage Regulation at Universal AC input

Primary-side Sensing and Regulation Without TL431 and Opto-coupler

Programmable CV and CC Regulation

Built-in Primary winding inductance compensation

Programmable cable drop compensation

Built-in soft start

Built-in Leading-edge blanking

Cycle by cycle over current protection (OCP)

VCC over voltage clamp & under voltage lockout( UVLO)

Maximum Gate output voltage clamped at 12V

Frequency jittering

Ultra low standby power (<100mW)

Structure Type		Part NO.	MOS	Package	App. Watt		OVP	PDF
					176-264Vac	90-264Vac
Isolation	PF﹥0.5	WS3252	-	SOT23-6	36W	36W	External Set

General Description

WS3252 is a high-integrated offline PWM controller, optimized for high performance 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.

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 and DIP-8 package.