用于回掃轉換器的固定頻率電流模式控制器 Fixed Frequency Current Mode Controller for Flyback Converters
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 VCC 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).
? 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 VCC 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)
? VCC Operation up to 28 V, with Overvoltage Detection
? 500 mA Peak Source / Sink Current Drive Capability
? 4.0 ms Soft?Start