ML4830

March 1997 ML4830* Electronic Ballast Controller GENERAL DESCRIPTION The ML4830 is a complete solution for a dimmable, high power factor, high efficiency electronic ballast. Contained in the ML4830 are controllers for “boost” type power factor correction as well as for a dimming ballast. The Power factor circuit uses the average current sensing method with a gain modulator and over-voltage protection. This system produces power factors of better than 0.99 with low input current THD at > 95% efficiency. Special care has been taken in the design of the ML4830 to increase system noise immunity by using a high amplitude oscillator, and a gain modulator. An overvoltage protection comparator stops the PFC section in the event of sudden load decrease. The ballast section provides for programmable starting scenarios with programmable preheat and lamp out-ofsocket interrupt times. The IC controls lamp output through either frequency or Pulse Width control using lamp current feedback. The ML4830 is designed using Micro Linear‘s SemiStandard tile array methodology. Customized versions of this IC, optimized to specific ballast architectures can be made available. Contact Micro Linear or an authorized representative for more information. FEATURES s Complete Power Factor Correction and Dimming Ballast Control on one IC Low Distortion, High Efficiency Continuous Boost, Average Current sensing PFC section Programmable Start Scenario for Rapid or Instant Start Lamps Selectable Variable Fre...