STR-X6700 Series Power IC for Quasi-Resonant Type Switching Power Supply with High Efficiency and Low Noise in Full Load Range ■ General Descriptions The STR-X6700 series products are power ICs for quasi-resonant type switching power supplies, incorporating a power MOSFET and a controller IC, The product achieves high efficiency and low noise power supply systems by the quasi-resonant operation and the bottom-skip quasi-resonant operation. The STR-W6700 series products are the different package (TO-220F) versions. ■ Features Multi-Mode Control TO-3PF-7 The operation mode switching with three steps according to load conditions achieves the optimal high efficiency and low noise power supply systems across the full load range. (The confirmation of product number is necessary because some functions are different in each product.) ・In Standby (Under Standby Load Conditions): －UVLO Intermittent Oscillation by low output voltage --- Switched by Standby Signal, or －Auto Burst-Oscillation --- Switched Automatically ・Under Low to Middle Load Conditions: Bottom-Skip Quasi-Resonant Operation (Bottom-Skip QR) ・Under Middle to Rating (or Heavy) Load Conditions: Quasi-Resonant Operation (QR) Current-Mode Control Built-in PWM Oscillator The PWM operates with the minimum frequency of around 22 kHz, until the quasi-resonant signal becomes valid, reduces the stress on components at startup and load-shorted. Soft-Start Function Step-Drive Function, reducing switching noise Built-in Maximum ON Time Limitation Circuit The function limits the maximum ON time of power MOSFET, during the transitions at low input voltage, power ON/OFF. Input Compensation at Overcurrent The function reduces the distortion of overcurrent operation point to AC input voltage change by adding three components. Built-in Avalanche Energy Guaranteed High-Voltage Power MOSFET Various Protections Overcurrent Protection (OCP) -------------------------------Pulse-by-Pulse Overload Protection (OLP)-----------------------------------Latch Shutdown Overvoltage Protection (OVP)-------------------------------Latch Shutdown ■ Applications Switching Power Supplies for Digital Consumer Equipment; LCD-TVs, PDP-TVs, CRT-TVs, etc., Home Appliances, OA Equipments, Industry Machines, Communication Devices, Others ■ Product Lineup MOSFET VDSS MIN (V) RDS(ON) MOSFET VDSS MIN (V) RDS(ON) STR-X6729 450 0.189 N Y STR-X6750F 650 0.62 Y N STR-X6737 500 0.36 Y Y STR-X6759N 650 0.385 N Y STR-X6737M 500 0.36 N Y STR-X6759F 650 0.385 Y N STR-X6756 650 0.73 Y Y STR-X6759B 650 0.385 N N STR-X6757 650 0.62 Y Y STR-X6768N 800 1.0 N Y STR-X6757N 650 0.62 N Y STR-X6769 800 0.66 Y Y STR-X6750B 650 0.62 N Y STR-X6769B 800 0.66 N N Product No. Y: Including the function MAX BurstOscillation BottomSkip QR Product No. (Ω) N: Excluding the function MAX BurstOscillation BottomSkip QR (Ω) ■ Typical Application Circuit VAC +B ErrAmp STR-X6700 1 D Vcc GND Standby ON/OFF Signal UVLO Intermittent Oscillation Circuit Example Low B 4 Cont． Standby VOUT Reg GND FB S 2 6 GND OCP/BD SS/OLP 3 7 5 Reg： Li near Regul ator IC from San ken, Other s ■ Typical Operation Waveforms Transitions between Bottom-Skip QR Operation and Quasi-Resonant Operation Load Change 100VAC Vin(AC) = 100V QR ID VDS Frequency fOSC (kHz) 1 BottomBottom-Skip QR STR-X6700 Input Power- Frequency Heavy Light 140 120 100 80 60 40 20 0 1Skip 0 50 QR 100 150 200 250 Input Power PIN (W) 240VAC Vin(AC) = 240V Frequency fOSC (kHz) 140 120 100 1Skip 80 60 40 20 0 0 50 100 150 200 250 Input Power PIN (W) Warning The contents in this document are subject to changes, for improvement and other purposes, without notice. Make sure that this is the latest version of the document before use. The operation and circuit examples in this document are provided for reference purposes only. Sanken assumes no liability for violation of industrial property, intellectual property, or other rights of Sanken or third parties, that stem from these examples. The user must take responsibility for considering and determining which objects the products in this document are used with. Although Sanken will continue to improve the quality and reliability of its products, semiconductor products, by their nature, have certain fault and failure rates. The user must take responsibility for designing and checking to secure the device and system so that a part failure may not lead to human injury, fire, damages, or other losses. The contents in this document must not be transcribed or copied without Sanken’s written consent. SANKEN ELECTRIC CO.,LTD.