STR-A6251M Datasheet | Allegro MicroSystems

g n i h tors c t i a Sw egul R Universal-Input/15 W 67 k Hz Flyback Switching Regulator The STR-A6251M is a 67 k Hz PWM topology (with ±5% frequency jittering for minimum EMI) regulator specifically designed to satisfy the requirements for increased integration and reliability in flyback converters. It incorporates a primary control and drive circuit with an avalanche-rated power MOSFET. This is a higher-frequency version of the STR-A6251. Covering the power range from below 21 watts for a 230 VAC input, or to 15 watts for a universal (85 to 264 VAC) input, this device can be used in a wide range of applications, from DVD players and VCR player/recorders to ac adapters for cellular phones and digital cameras. An auto-burst standby function reduces power consumption at light load, while multiple protections, including the avalanche-energy guaranteed MOSFET, provide high reliability of system design. Cycle-by-cycle current limiting, undervoltage lockout with hysteresis, overvoltage protection, and thermal shutdown protect the power supply during the normal overload and fault conditions. Overvoltage .. protection and thermal shutdown are latched after a short delay. The latch may be reset by cycling the input supply. Low start-up current and a low-power standby mode selected from the secondary circuit pletes a prehensive suite of Features . It is provided in an 8-pin mini-DIP plastic package with pin 6 removed. Features AND BENEFITS - 67 k Hz PWM with ±5% Frequency Jittering Cost Reduction of EMI Noise Filtering - Rugged 650 V Avalanche-Rated MOSFET Simplified Surge Absorption No VDSS Derating Required - Low r DS(on) (3.95 Ω maximum) - Auto-Burst Mode for Stand-By Operation or Light Loads Less Transformer Audible Noise - Built-In Leading Edge Blanking - Soft Start and Low Start-Up Current Start-Up Circuit Disabled in Operation - Low Operating Current (4 m A max) - Automatic Burst Stand-By (intermittent operation) Input Power <0.1 W at No...