OB3398Ex Primary Side Regulation Off-line LED Lighting Power Switch

OB3398Ex is a primary side regulation off-line LED lighting power switch which can achieve accurate LED current. It significantly simplifies LED lighting system design by eliminating the secondary side feedback circuitry. Proprietary Constant Voltage (CV) and Constant Current (CC) control is integrated as shown in the figure below. The LED current (CC control) can be adjusted externally by the resistor Rs at CS pin. OB3398Ex offers comprehensive protection coverage with auto-recovery features including Cycle-by-Cycle current limiting, VDD clamp and UVLO. OB3398Ex is offered in DIP8/SOP7 package. Fig.1. Typical CC/CV Curve

Key Features

• High Precise Constant Current Regulation at Universal AC input
• Primary-side Sensing and Regulation Without TL431 and Opto-coupler
• HV MOSFET integrated
• Floating PSR control scheme with two transformer windings
• Adjustable Constant Current and Output Power Setting
• Built-in Primary winding inductance compensation
• Built-in Leading Edge Blanking (LEB)
• Cycle-by-Cycle Current Limiting
• VDD Under Voltage Lockout with Hysteresis (UVLO)
• Latched over temperature protection (OTP)
• VDD Clamp

Applications

• Low Power AC/DC offline SMPS for
• LED applications

Part Numbers and Specifications

Product family: On-Bright official page