RS2112 High Precision CC/CV Primary-Side PWM Power Switch DESCRIPTION RS2112 is a high performance offline PSR controller for low power AC/DC charger and adapter applications. It operates in primary‐ side sensing and regulation. Consequently, opto-coupler and TL431 could be eliminated. Proprietary Constant Voltage (CV) and Constant Current (CC) control is integrated as shown in the figure below. In CC control, the current and output power setting can be adjusted externally by the sense resistor Rs at CS pin. In CV control, PFM operations are utilized to achieve high performance and high efficiency. In addition, good load regulation is achieved by the built-in cable drop compensation. The chip consumes very low operation current (typical 350μA), it can achieve less than 30mW standby power to meet strict standby power standard. RS2112 offers comprehensive protection coverage with auto-recovery features including Cycle-by-Cycle current limiting, VDD over voltage protection, feedback loop open protection, short circuit protection, built‐ in leading edge blanking, VDD under voltage lockout (UVLO), etc. FEATURES ±5% constant voltage regulation at universal AC input High precision constant current 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 700V power BJT Ultra low start-up current (Typ. 1μA) VDD over voltage protection Built-in feedback loop open protection Built-in short circuit protection Built-in leading edge blanking (LEB) Cycle-by-cycle current limiting VDD under voltage lockout with hysteresis (UVLO) SOP-8 green packaging APPLICATIONS Low power AC/DC offline SMPS <5W LED Lighting for bulbs and spot light TYPICAL CC/CV CURVE Tel: 886-66296288‧Fax: 886-29174598‧ http://www.princeton.com.tw‧2F, No. 233-1, Baociao Rd., Sindian Dist., New Taipei City 23145, Taiwan RS2112 BLOCK DIAGRAM TYPICAL APPLICATION V1.0 2 June 2013 RS2112 ORDER INFORMATION Device Device Code RS2112 Y Z Y is package & Pin Assignments designator: S: SOP-8 Z is Lead Free designator: P: Commercial Standard, Lead (Pb) Free and Phosphorous (P) Free Package G: Green (Halogen Free with Commercial Standard) PIN ASSIGNMENTS PIN DESCRIPTION Pin Name VDD VC CS Supply voltage pin. Low pass filter capacitor for cable compensation. Voltage feedback pin. Output current of this pin could controls the PWM duty cycle, OLP and SCP. Current sense pin, a resistor connects to sense the NPN current. LD The connector of NPN. FB GND V1.0 Description GND Pin. 3 Pin No. 1 2 3 4 5 6 7 8 June 2013 RS2112 IMPORTANT NOTICE Princeton Technology Corporation (PTC) reserves the right to make corrections, modifications, enhancements, improvements, and other changes to its products and to discontinue any product without notice at any time. PTC cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a PTC product. No circuit patent licenses are implied. Princeton Technology Corp. 2F, 233-1, Baociao Road, Sindian Dist., New Taipei City 23145, Taiwan Tel: 886-2-66296288 Fax: 886-2-29174598 http://www.princeton.com.tw V1.0 11 June 2013