LM5025,pdf datasheet (Active C

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 compared
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 compound 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.