onsemi NCP1244
The NCP1244 is a new fixed−frequency current−mode controller featuring the Dynamic Self−Supply. This 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 start−up, transients, latch, stand−by etc. This device contains a special HV detector which detect the application unplug from the AC input line and triggers the X2 discharge current.FEATURES
PIN CONNECTIONS● Fixed−Frequency Current−Mode Operation (65 kHz and 100 kHz frequency options)
● Frequency Foldback then Skip Mode for Maximized Performance in Light Load and Standby Conditions
● Timer−Based Overload Protection with Latched (Option A) or Latch 1 FB 2 CS 3 GND 4 8 HV 6 VCC 5 DRV Auto−Recovery (Option B) Operation (Top View)
● High−voltage Current Source with Dynamic Self−Supply, Simplifying the Design of the VCC Circuitry
● Frequency Modulation for Softened EMI Signature
● Adjustable Overpower Protection Dependant on the Bulk Voltage ORDERING INFORMATION See detailed ordering and shipping information in the package dimensions section on page 39 of this data sheet.
● Latch−off Input Combined with the Overpower Protection Sensing Input
● VCC Operation up to 28 V, With Overvoltage Detection
● 500/800 mA Source/Sink Drive Peak Current Capability Typical
APPLICATIONS
● AC−DC Adapters for Notebooks, LCD, and Printers● 10 ms Soft−Start
● Offline Battery Chargers
● I...