- Internal start-up bias regulator
- 3A composite main door driver
- Programmable Line Adjustable Hysteresis Undervoltage Lockout (UVLO)
- With feed-forward voltage mode control
- Adjustable dual-mode overcurrent protection
- Programmable primary and active clamped outputs between overlap or dead bands
- Volt x two clamps
- Programmable soft-start
- Cutting-edge blanking
- Single-resistor programmable oscillator
- Oscillator up/down synchronization function
- Precision 5V reference
- Thermal shutdown
illustrate
The LM5025C is a functional variation of the LM5025's active-clamped PWM controller. The functional difference between the LM5025C is that the maximum duty cycle of the LM5025C has increased from 80% to 91%. The charging current of the soft-start capacitor increases, from 20μA to 90μA. From 25 mA to 55 mAh VCCThe regulator's current limit threshold increases. The current limit threshold for CS1 and CS2 has been increased to 0.5V. The internal CS2 filter discharge device has been disabled and no longer operates every clock cycle. Internal VCCand VREFThe regulator continues to operate when the line UVLO pin falls below the threshold.
The LM5025C PWM controller contains all the necessary functions to implement the power converter, utilizing active clamp/reset technology. Active clamping technology, higher efficiency and greater power density, enables clamping/reset techniques compared to traditional catch-up winding or RDC techniques. Two control outputs are available, main power switch control (OUT_A) and active clamp switch control (OUT_B). Two internal composite gate drive parallel MOS and bipolar devices provide superior gate drive characteristics. The controller is designed for high-speed operation, including an oscillator with a frequency range of up to 1MHz and total PWM and current sensing propagation delay of less than 100 ns. The LM5025C includes a high voltage start-up regulator with a wide input range of over 13V to 90V. Other features include line undervoltage lockout (UVLO), soft-start, oscillation up/down synchronization, accurate reference, and thermal shutdown.
|