• Secondary Side Regulation
• Integrated 1000V Power MOSFET
• HV Startup
• 60kHz Rated Switching Frequency
• Switching Frequency up to 178kHz under Peak Power Mode to Prevent Magnetic Field Interference
• Pseudo Fixed Frequency Control to Eliminate Slope Compensation for CCM (Duty Cycle > 50%)
• Frequency Fold back Control for High Average Efficiency
• Burst Mode Control for High Light-Load Efficiency
• 25kHz Minimum Switching Frequency to Eliminate Audible Noise
• Frequency Modulation to Reduce EMI Noise
• Internal Soft-Start Process
• Programmed Brown in Voltage
• OLP, VCC OVP, OTP Protections
• Compact DIP7 Package

The SQ38576A is a secondary side regulation (SSR) flyback switcher featuring pulse width modulation and pulse frequency modulation (PWM/PFM) operation. Its 60kHz rated switching frequency can rise to 178kHz under peak power mode to prevent magnetic field interference. It integrates a 1000V power MOSFET within a DIP7 package. Integrated high voltage (HV) startup minimizes no-load loss. The pseudo fixed frequency control strategy avoids sub-harmonic oscillation problems under continuous conduction mode (CCM). For high average efficiency, the SQ38576A will enter frequency fold back mode when load decreases. It will enter burst mode under light load conditions. It features switching frequency modulation to reduce electromagnetic interference (EMI) noise, and soft-start to reduce current and voltage stress on the power device during VIN start up. It also features programming brown in (BI) voltage by CONT pin.

The SQ38576A provides reliable protections for overload (OLP), VCC overvoltage (OVP), and over temperature (OTP).

The SQ38576A is available in a compact DIP7 package.