Power chip

Valley switching converters typically have lower EMI and higher power conversion efficiency than traditional hard-switching converters with fixed switching frequency. The FSQ series is an integrated pulse width modulation (PWM) controller and SenseFET designed for valley switching operation with minimal external parts count. The PWM controller includes an integrated fixed frequency oscillator, undervoltage lockout, leading edge spacing (LEB), optimized gate drivers, internal soft-start, temperature compensated precision current source for loop compensation, and self-protection circuitry. Compared to discrete MOSFET and PWM controller solutions, the FSQ family reduces overall cost, parts count, size and weight; while improving energy efficiency, productivity and system reliability. This device is a basic platform for cost-effective designs of valley-switching flyback converters.

The NCP1239 is a fixed frequency current mode controller with dynamic self-supply capability. This feature activates the internal start-up current source to power the controller during start-up, transients, latch-up, standby, etc., greatly simplifying the design of the auxiliary power supply and Vcc capacitor. The controller has a supply range up to 35 V, has a dithered 65 kHz or 100 kHz switching circuit, and operates under peak current mode control. When the power on the auxiliary side starts to decrease, the controller automatically folds back its switching frequency to a minimum of 26 kHz. As power drops further, the part skips cycles while limiting peak current to ensure excellent efficiency at light loads. It features timer-based fault detection to ensure overload detection and adjustable compensation to help maintain maximum power regardless of input voltage.

Economical Primary Side Controller 8-TSSOP 0 to 70

Buck - Switching Regulator - IC - Positive or Negative - Fixed - 3.3V - 1 - Output - 100mA - 8 - WFDFN - Exposed Pad