100V PWM Controller Features Active Clamp

Reported as an industry first, the LM5025 100V PWM controller employs an active clamp/reset technique, allowing operation at duty cycles above 50% and higher primary-to-secondary turns ratios in the power transformer. With the active clamp output, the controller can be configured to provide either overlap time for P-channel switch applications or dead-off time for N-channel switch applications. The device operates on input voltages from 13V to 100V and integrates a 100V start-up bias regulator and a user-programmable oscillator operating at 1 MHz. Other features include total propagation delays of less than 100 ns, dual-mode over-current protection, oscillator-synchronization circuitry, and a unique 3A-peak compound gate-driver technology that makes the device suitable for directly driving a high-power MOSFET. Available in an LLP-16 or TSSOP-16 package, price is $1.30 each/1,000. NATIONAL SEMICONDUCTOR CORP., Santa Clara, CA. (800) 272-9959.