LM5025 Datasheet | National Semiconductor

Description The LM5025 PWM controller contains all of the features necessary to implement power converters utilizing the Active Clamp / Reset technique. The device can be configured to control either a P-Channel clamp switch or an N-Channel clamp switch. With the active clamp technique, higher efficiencies and greater power densities can be realized pared to conventional catch winding or RDC clamp / reset techniques. Two control outputs are provided, the main power switch control (OUT_A) and the active clamp switch control (OUT_B). The active clamp output can be configured for either a guaranteed overlap time (for P-Channel switch applications) or a guaranteed deadtime (for N_Channel applications). The two internal pound gate drivers parallel both MOS and Bipolar devices, providing superior gate drive characteristics. This controller is designed for high-speed operation including an oscillator frequency range up to 1MHz and total PWM and current sense propagation delays less than 100ns. The LM5025 includes a high-voltage start-up regulator that operates over a wide input range of 13V to 90V. Additional features include: Line Under Voltage Lockout (UVLO), softstart, oscillator UP/DOWN sync capability, precision reference and thermal shutdown. Features n Internal Start-up Bias Regulator n 3A pound Main Gate Driver n Programmable Line Under-Voltage Lockout (UVLO) with Adjustable Hysteresis n Voltage Mode Control with Feed-Forward n Adjustable Dual Mode Over-Current Protection n Programmable Overlap or Deadtime between the Main and Active Clamp Outputs n Volt x Second Clamp n Programmable Soft-start n Leading Edge Blanking n Single Resistor Programmable Oscillator n Oscillator UP / DOWN Sync Capability n Precision 5V Reference n Thermal Shutdown Packages n TSSOP-16 n LLP-16 (5x5 mm) Thermally Enhanced Typical Application Circuit Simplified Active Clamp Forward Power Converter © 2004 National Semiconductor Corporation DS200869 .national. Connect...