OB6683

GENERAL DESCRIPTION

OB6683 integrates a transition mode power factor correction (TM PFC) controller and a Quasi-Resonant (QR) controller in one chip. The PFC controller provides a cost effective solution for optimizing the power factor. The QR controller provides higher efficiency and lower EMI compared to conventional PWM system.

OB6683 provides high level integration and high performance than conventional PFC/PWM system. The built-in TM PFC controller optimizes power conversion efficiency with reduced system cost. The intelligent PFC switching ON and OFF, zero current detection and frequency limitation mechanism enable a better efficiency under any load conditions.

OB6683 features many built-in green functions to optimize power conversion efficiency at all power levels. This holds for QR operation at high power levels, as well as PFM operation at lower power levels, and ‘Extended Burst Mode’ operation at very low power or zero power (Standby) levels. At low power levels, OB6683G can turn off the PFC stage. In this way, low standby together with low system cost can be achieved.

The device is also integrated many functions of protection, such as X-CAP discharge, Brown-in/out protection, VCC Under Voltage Lockout (UVLO), Cycle-by-Cycle Current Limiting for PFC and QR Stage (OCP), Output Over Voltage Protection for PFC and QR Stage (OVP), Open Loop Protection for PFC and QR Stage (OLP), Programmable Over Temperature Protection (OTP), Built-in Soft Start in QR Stage, VCC Over Voltage Protection, Gate Clamp , Pin Floating Protection, and External Latch Triggering,  etc.  Therefore it can protect the system from damage due to occasional failure.

OB6683 is offered in SOP-16 packages.

FEATURES

■   Integrated PFC Controller and QR  Controller

■   Transition Mode PFC Controller

■   Multi-Mode Operation for QR Stage

■   Line Voltage Compensation for QR Stage

■   Enhanced Dynamic Response for PFC Stage

■   PFC Light Load Turn Off Control

■   Audio Noise Free Operation

■   Valley Switching Operation with Valley lockout

■   External Latch Triggering for Both Converters

■   Minimum OFF time for Ringing Suppression

■   Maximum ON Time Limit for QR Stage

■   Built-in 4ms Soft Start for QR Stage

■   Internal Leading Edge Blanking for QR Stage

■   Internal Leading Edge Blanking for PFC Stage

■   Built-in X-CAP Discharge

 

PROTECTIONS

■   Output Over Voltage Protection for PFC stage

■   Output Over Voltage Protection for QR stage

■   Output Diode Short Protection for QR stage

■   VCC Over Voltage Protection

■   Under Voltage Lockout with Hysteresis

■   Over Load Protection for QR stage

■   Cycle-by-Cycle Current Limiting for PFC stage

■   Cycle-by-Cycle Current Limiting for QR stage

■   Brownout Protection (BOP)

■   PFC Inductor Short Circuit Protection

■   Programmable Over Temperature Protection

■   Internal Over Temperature Protection

 

APPLICATIONS

Offline AC/DC flyback converter for

■   General LED Lighting

■   LCD Monitor/TV/PC

■   Notebook

■   ACDC High Power Adapter

■   Open Frame SMPS
 

TYPICAL APPLICATION