EVLB001 Datasheet, PDF (17/35 Pages) ATMEL Corporation – Automatic microcontroller dimmable ballast

Device Design & Application
5.5
IXYS IXTP3N50P The IXTP3N50P is a 3A 500V general purpose power MOSFET that comes from the
PolarHV^TM N-
family of IXYS PolarHV MOSFETs. When comparing equivalent die sizes, PolarHT
Channel Power
MOSFET
results in 50% lower RDS(ON), 40% lower RTHJC (thermal resistance, junction to
case), and 30% lower Qg (gate charge) enabling a 30% - 40% die shrink, with the same
or better performance versus the 1st generation power MOSFETs.
Within the ballast demonstrator itself the IXTP3N50 serves two functions. The first of
which is the power switching pair of devices in the half-bridge circuit that drives the
lamps. While a third device serves in the main PFC circuit as the power switch that
drives the PFC inductor.
5.6
Clare LDA111S Clare's family of single and dual optocoupler provide an optically isolated means of
Optocoupler
switching control circuits. The LDA111S contains one phototransistor that is optically
coupled to an LED. Shunt resistors can be used to adjust the threshold currents
required to activate the output circuitry. While both AC and DC input versions are avail-
able, the LDA111S is a DC input only model and features a 100mA continuous load
rating, 3750VRMS input to output isolation, and a 1000% current transfer ratio.
The LDA111S role is to isolate control signals within the ballast design.
5-15
7597B–AVR–10/07
ATAVRFBKIT / EVLB001 User Guide