onsemi AC DC Converters, Offline Switches NCP1237AD65R2G

The NCP1237AD65R2G is a fixed-frequency current-mode controller designed for flyback converters, operating at a frequency of 65 kHz. It features Dynamic Self-Supply (DSS), which simplifies the design of the auxiliary supply and VCC capacitor by activating an internal startup current source during transients. The controller incorporates a proprietary Soft-Skip,Ñ¢ mode combined with frequency foldback, enhancing efficiency at light loads and minimizing standby power consumption. This feature also reduces the risk of acoustic noise, allowing for the use of cost-effective transformers and capacitors. The NCP1237AD65R2G includes dual-level timer-based fault detection for controlling transient peak power, with options for auto-recovery or latched operation. It has built-in protections against brown-out conditions and line overvoltage, and its high-voltage circuitry can sense input voltage from either the rectified AC line or the DC filtered bulk voltage. The device operates over a temperature range of -40¬8C to +125¬8C, with critical parameters tightly controlled, such as a ¬±5% peak current limit and ¬±7% oscillator precision. Typical applications include AC-DC adapters for notebooks and consumer electronics, offline battery chargers, and auxiliary power supplies.