onsemi FSBH0370NY

The highly integrated FSBH-series consists of an integrated current-mode Pulse Width Modulator (PWM) and an avalanche-rugged 700V SenseFET. It is specifically designed for high-performance offline Switch Mode Power Supplies (SMPS) with minimal external components. The integrated PWM controller features include a proprietary green-mode function that provides off-time modulation to linearly decrease the switching frequency at light-load conditions to minimize standby power consumption. To avoid acoustic-noise problems, the minimum PWM frequency is set above 18kHz. This green-mode function enables the power supply to meet international power conservation requirements. The PWM controller is manufactured using the BiCMOS process to further reduce power consumption. The FSBH-series turns off some internal circuits to improve power saving when VFB is lower than 1.6V, which allows an operating current of only 2.5mA. The FSBH-series has built-in synchronized slope compensation to achieve stable peak-current-mode control. The proprietary external line compensation ensures constant output power limit over a wide AC input voltage range, from 90VAC to 264VAC. The FSBH-series provides many protection functions. In addition to cycle-by-cycle current limiting, the internal open-loop protection circuit ensures safety when an open-loop or output short occurs. PWM output is disabled until VDD drops below the VTH-OLP, then the controller starts up again. As long as VDD exceeds 28V, the internal OVP circuit is triggered. Compared with a discrete MOSFET and controller or RCC switching converter solution, the FSBH-series reduces total component count, design size, and weight; while increasing efficiency, productivity, and system reliability. These devices provide a basic platform that is well suited for the design of cost-effective flyback converters, such as in PC auxiliary power supplies.

• Brownout Protection with Hysteresis
• Built-In 5ms Soft-Start Function
• Internal Avalanche-Rugged 700V SenseFET
• No Acoustic Noise During Light-Load Operation
• High-Voltage Startup
• Linearly Decreasing PWM Frequency to 18KHz
• Peak-Current-Mode Control
• Cycle-by-Cycle Current Limiting
• Leading-Edge Blanking (LEB)
• Synchronized Slope Compensation
• Internal Open-Loop Protection
• VDD Under-Voltage Lockout (UVLO)
• VDD Over-Voltage Protection (OVP)
• Internal Auto-Restart Circuit (OVP, OTP)
• Constant Power Limit (Full AC Input Range)
• Internal OTP Sensor with Hysteresis
• VIN Pin for Pull-HIGH Latch Function and Pull-LOW Auto-Recovery Protection

• General-purpose switch-mode power supplies and flyback power converters
• Auxiliary Power Supply for PC and Server
• SMPS for VCR, SVR, STB, DVD & DVCD Player, Printer, Facsimile, and Scanner
• Adapter for Camcorder