** The NCP1236 is a new fixed−frequency current−mode controller

featuring Dynamic Self−Supply (DSS). This device is pin−to−pin compatible with the previous NCP12xx families. **

The DSS function greatly simplifies the design of the auxiliary supply and the V CC capacitor by activating the internal startup current source to supply the controller during transients.
Finally, due to a careful design, the precision of critical parameters is well controlled over the entire temperature range (−40  C to +125  C).

** Features **

 Fixed−Frequency Current−Mode Operation with Built−In Ramp Compensation
 65 kHz or 100 kHz Oscillator Frequency
 Frequency Foldback then Skip Mode for Maximized Performance in Light Load and Standby Conditions
 Timer−Based Overload Protection with Latched (option A) or Auto−Recovery (option B) Operation, Shortened Overload Timer for Increased Safety (options C and D)
 High−voltage Current Source with Brown−Out
detection and Dynamic Self−Supply, Simplifying the Design of the V CC Capacitor
 Frequency Modulation for Softened EMI Signature, including during Frequency Foldback mode
 Adjustable Overpower Compensation
 Latch−off Input for Severe Fault Conditions, Allowing Direct Connection of an NTC for Overtemperature Protection (OTP)
 V CC Operation up to 28 V, with Overvoltage Detection
 500 mA Peak Source / Sink Current Drive Capability
 4.0 ms Soft−Start