NCP1236DD65R2G

The NCP1236 is a new fixed frequency current mode controller with dynamic self-powering (DSS) capability. Pin compatible with the previous NCP12xx family, the DSS feature activates an internal start-up current source to power the controller during transients, greatly simplifying the design of auxiliary power supplies and VCC capacitors. Due to the frequency foldback, the controller offers excellent power efficiency under light load conditions while achieving very low standby power consumption. With internal frequency jitter, ramp compensation and a multi-function latch input, this controller is ideal for converters where component cost is a key limiting factor. In addition, the controller includes a new high-voltage circuit that combines a start-up current source and an undervoltage detector to sense input voltages from rectified AC lines or large DC filtered voltages. The high-voltage sensing circuit is also used for over-power protection purposes. Over-power protection, overload protection and other protection features enhance the safety and reliability of the final application.