dt95-3| Application Note
DESIGN TIP
Summary:
DT 95-3
International Rectifier 233 Kansas Street El Segundo CA 90245 USA
Ultra-Compact Flourescent Ballasts using the IR51H420 Hybrid
Notices: (HEXFET is the trademark for International Rectifier Power MOSFETs)
Figure 1 The IR2151 has set the standard for low cost compact fluorescents which demand minimum size ballasts in order to fit into unmodified light fixtures designed for the ubiquitous tungsten filament light bulb of 60 - 100W rating. IR has now combined the (2) inverter MOSFETs with the IR2151 driver to produce on even more compact ballast which can now be built within the footprint of the lamp itself!
The above schematic shows the extreme simplicity of the ballast circuit. Note the back-to-back IN4001 diodes which form a zero current crossing detection circuit for synchronizing the oscillator to the natural frequency of the series resonant lamp circuit. Features: Floating channel designed for bootstrap operation Fully operational to +500V Tolerant to negative transient voltage dV/dt immune Under voltage lockout Programmable oscillator frequency
