Part # LM5025A datasheet

Part Manufacturer: National Semiconductor

National Semiconductor

Part Description: LM5025A Active Clamp Voltage Mode PWM Controller

Part Details:

LM5025A December 2004 LM5025A Active Active Clamp Voltage Mode PWM ControllerGeneral Description Features Clamp The LM5025A is a functional variant of the LM5025 active n Internal Start-up Bias Regulator clamp PWM controller. The functional differences of the n 3A Compound Main Gate Driver LM5025A are: The CS1 and CS2 current limit thresholds n Programmable Line Under-Voltage Lockout (UVLO) with have been increased to 0.5V. The internal CS2 filter dis- Adjustable Hysteresis charge device has been disabled and no longer operates V n Voltage Mode Control with Feed-Forward each clock cycle. The internal V and V regulators oltage CC REF n Adjustable Dual Mode Over-Current Protection continue to operate when the line UVLO pin is below thresh- n Programmable Overlap or Deadtime between the Main old. and Active Clamp Outputs The LM5025A PWM controller contains all of the features n Volt x Second Clamp necessary to implement power converters utilizing the Active n Programmable Soft-start Mode Clamp / Reset technique. With the active clamp technique,higher efficiencies and greater power densities can be real- n Leading Edge Blanking ized compared to conventional catch winding or RDC clamp n Single Resistor Programmable Oscillator / reset techniques. Two control outputs are provided, the n Oscillator UP / DOWN Sync Capability main power switch control (OUT_A) and the active clamp PWM n Precision 5V Reference switch control (OUT_B). The two internal compound gate n Thermal Shutdown drivers parallel both MOS and Bipolar devices, providingsuperior gate drive characteristics. This controller is de- Packages signed for high-speed operation including an oscillator fre- Controller quency range up to 1MHz and total PWM and current sense n TSSOP-16 propagation delays less than 100ns. The LM5025A includes n LLP-16 (5x5 mm) Thermally Enhanced a high-voltage start-up regulator that operates over a wideinput range of 13V to 90V. Additional features include: LineUnder Voltage Lockout (UVLO), softstart, oscillator UP/DOWN sync capability, precision reference and thermalshutdown. Typical Application Circuit

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LM5025A.pdf Datasheet