DESCRIPTION
RS2138A is a high performance offline PSR controller for low power AC/DC charger and adapter applications, Less than 75mW standby power consumption with typical application. It operates in primary-side sensing and regulation, so opto-coupler and TL431 could be eliminated. In CC control, the current and output power can be adjusted externally by the sense resistor RS at CS pin. In CV control, a PFM operation is utilized to achieve high performance and high efficiency. In addition, good load regulation is achieved by the built-in cable drop compensation.

FEATURES
• Standby power less than 75mW
• Primary-side Sensing and Regulation Without
   TL431 and Opto-coupler
• High precision constant voltage and current
   regulation at Universal AC input
• Programmable CV and CC Regulation
• Multi-mode PWM/PFM operation for efficiency
   improving
• Audio noise free operation
• Programmable Cable Drop Compensation
• Built-in line voltage and primary winding
   inductance compensation
• No need for control loop compensation
• Built-in Feedback Loop Open Protection
• VDD Over Voltage Protection
• VOUT Over Voltage Protection
• Built-in Short Circuit Protection
• Built-in Leading Edge Blanking (LEB)
• Over temperature protection(OTP)
• Cycle-by-Cycle Current Limiting
• VDD Under Voltage Lockout with Hysteresis
   (UVLO)
• DIP-8L green Package

APPLICATIONS
• Switching AC/DC Small Power Adaptor
• Cell Phone Charger
• Digital Cameras Charger
• Auxiliary Power for PC, TV etc
• Linear Regulator/RCC Replacement