LD5523K 04/23/2019 Multi-Mode PWM Controller of Flyback with Integrated BNI/BNO and Bulk cap. OVP REV. 01 Features General Description Secondary-side feedback control with In order to enhance the efficiency performance, the quasi-resonant + CCM operation LD5523K integrates the multi-mode PWM controller, Low Startup Current (<1 A) which consists of Quasi-Resonant (QR) PWM control for 0.285mA Ultra-low operating current at light load light load condition and Continue Conduction Mode Current Mode Control with Cycle-by-Cycle Current (CCM) for heavy load condition. Moreover, the QR Limit Green Mode Control controller not only gains the system performance, but UVLO (Under Voltage Lockout) also brings the worse EMI capability, while the LEB (Leading-Edge Blanking) on CS Pin frequency swapping function of LD5523K can reduce VCC OVP (Over Voltage Protection) the EMI emission of SMPS and helps the power circuit Adj. OVP / UVP on FB pin designers to simply deal with EMI filter and saves Adj. BNI/BNO, Bulk cap. OVP on FB pin several component and developing time. OLP (Over Load Protection) External OTP (Over Temperature Protection) on The LD5523K is implemented in SOT-26 package, and CS Pin includes the comprehensive protection function, such as Internal OTP (Over Temperature Protection) Over Load Protection (OLP), Over Voltage Protection SDSP (Secondary Diode Short Protection) (OVP), Output Short Circuit Protection (OSCP) and Gate Source/Sink Capability: 220mA/-350mA internal Over Temperature Protection (OTP). output pin with 33nF capacitor. Furthermore, the programmable brown-in/out and bulk Applications cap. OVP protection is built-in. Switching AC/DC Adaptor Typical Application DC AC EMI Output input Filter VCC OUT FB LD5523K photocoupler CS COMP GND NTC 1 Leadtrend Technology Corporation www.leadtrend.com.tw LD5523K-DS-01 April 2019 LD5523K 04/23/2019 Pin Configuration SOT-26 (TOP VIEW) DIP-8 (TOP VIEW) OUT VCC CS 8 7 6 5 6 5 4 23K YWt TOP MARK PP 1 2 3 YYWWPP 1 YY2W W3 PP4 GND COMP FB Y : Year code (D: 2004, E: 2005 ..) YY : Year code W : Week code WW : Week code PP : Production code PP : Production code t23K : LD5523K Ordering Information Part number Package TOP MARK Shipping YWt/23K/PP LD5523K GL SOT-26 (Green Package) 3000 /tape & reel LD5523K GN DIP-8 (Green Package) LD5523KGN 3600 /tube /carton The LD5523K is RoHs compliant/ green packaged. Protection Mode Product Switching Bulk cap VCC OVP FB OVP OSCP OLP BNI/BNO CS OTP Int. OTP SDSP Name Freq. OVP Auto Auto Auto Auto Auto Auto Auto Auto Auto LD5523K 65kHz recovery recovery recovery recovery recovery recovery recovery recovery recovery Pin Descriptions PIN Pin NAME FUNCTION (SOT-26) (DIP-8) GND 1 8 Ground COMP 2 7 Output of the error amplifier for voltage compensation Auxiliary voltage sense, brown in/out and Quasi Resonant detection FB 3 5 CS 4 4 Current sense pin, connect to sense the MOSFET current VCC 5 2 Supply voltage pin OUT 6 1 Gate drive output to drive the external MOSFET NC 3 Unconnected Pin NC 6 Unconnected Pin 2 Leadtrend Technology Corporation www.leadtrend.com.tw LD5523K-DS-01 April 2019 OUT GND COMP VCC NC NC FB CS