SG5842A/SG5842JA Highly Integrated Green-Mode PWM Controller December 2009 SG5842A/SG5842JA Highly Integrated Green-Mode PWM Controller Features Description The highly integrated SG5842A/JA series of PWM Green-Mode PWM Controller controllers provides several features to enhance the Low Startup Current: 14A performance of flyback converters. To minimize standby power consumption, a proprietary green-mode function Low Operating Current: 4mA provides off-time modulation to continuously decrease Programmable PWM Frequency with Hopping the switching frequency at light-load conditions. To (SG5842JA) avoid acoustic-noise problems, the minimum PWM frequency set above 22KHz. This green-mode function Peak-Current-Mode Control enables the power supply to meet international power Cycle-by-Cycle Current Limiting conservation requirements. To further reduce power consumption, SG5842A/JA is manufactured using the Synchronized Slope Compensation BiCMOS process. This allows a low startup current, Leading-Edge Blanking (LEB) around 14A, and an operating current of only 4mA. As a result, a large startup resistance can be used. Constant Output Power Limit The SG5842A/JA built-in synchronized slope Totem-Pole Output with Soft Driving compensation achieves stable peak-current-mode V Over-Voltage Protection (OVP) control. SG5842JA integrates a frequency-hopping DD function that helps reduce EMI emission of a power Programmable Over-Temperature Protection (OTP) supply with minimum line filters. Internal Latch Circuit (OTP, OVP) SG5842A/JA provides many protection functions. In Internal Open-Loop Protection addition to cycle-by-cycle current limiting, the internal open-loop protection circuit ensures safety should an V Under-Voltage Lockout (UVLO) DD open-loop or output short-circuit failure occur. PWM GATE Output Maximum Voltage Clamp: 18V output is disabled until V drops below the UVLO lower DD limit, then the controller starts again. As long as V DD exceeds about 24V, the internal OVP circuit is triggered. Applications An external NTC thermistor can be applied for over- temperature protection. General-purpose switch-mode power supplies and flyback power converters, including: SG5842A/JA is available in an 8-pin DIP or SOP package. Notebook Power Adapters Open-Frame SMPS 2007 Fairchild Semiconductor Corporation www.fairchildsemi.com SG5842A/SG5842JA Rev. 1.4.3 SG5842A/SG5842JA Highly Integrated Green-Mode PWM Controller Ordering Information Operating OTP OVP Frequency Eco Part Number Temperature Package Status Latch Latch Hopping Range SG5842JASZ -40C to +105C RoHS 8-Pin Small Outline Package (SOP) Yes Yes Yes SG5842JADZ -40C to +105C RoHS Yes Yes Yes 8-Pin Dual Inline Package (DIP) SG5842JASY -40C to +105C Green 8-Pin Small Outline Package (SOP) Yes Yes Yes SG5842ASZ -40C to +105C RoHS 8-Pin Small Outline Package (SOP) Yes Yes No (Preliminary) SG5842ASY -40C to +105C Green 8-Pin Small Outline Package (SOP) Yes Yes No (Preliminary) For Fairchilds definition of Eco Status, please visit: