LM5025B

LM5025B www.ti.com SNVS354B – JULY 2005 – REVISED MARCH 2013 LM5025B Active Clamp Voltage Mode PWM Controller Check for Samples: LM5025B FEATURES 1 2 Internal Start-Up Bias Regulator 3A Compound Main Gate Driver Programmable Line Under-Voltage Lockout (UVLO) with Adjustable Hysteresis Voltage Mode Control with Feed-Forward Adjustable Dual Mode Over-Current Protection Programmable Overlap or Deadtime between the Main and Active Clamp Outputs Volt x Second Maximum Duty Cycle Clamp Programmable Soft-Start Current Sense Leading Edge Blanking Single Resistor Programmable Oscillator Oscillator Up / Down Sync Capability Precision 5V Reference Thermal Shutdown PACKAGES TSSOP-16 WSON-16 (5x5 mm) Thermally Enhanced DESCRIPTION The LM5025B is a functional variant of the LM5025 active clamp PWM controller. The functional differences of the LM5025B are as follows: The maximum PWM duty cycle is limited to less than 75% to reduce voltage stress on the power MOSFETs. The CS2 hiccup mode threshold is increased to 0.5V The CS2 filter discharge device is disabled The VCC regulator continues to operate when the line UVLO is below the threshold of normal operation The VREF regulator is switched off when the line UVLO input falls below the operating threshold The internal 5kΩ COMP pin pull-up resistor is removed The LM5025B PWM controller contains all of the features necessary to implement power converters utilizing the Active Clamp / Reset technique. ...