AN1902 Datasheet, PDF (22/32 Pages) STMicroelectronics – DEVICES TO DRIVE 58W TL TUBES

Figure 23: PCB Ground path
Signal Ground
AN1902 - APPLICATION NOTE
Power Ground
t(s) ^{4.4. EXPERIMENTAL RESULTS}
c _{For the board testing it is important to connect on the input terminals an electrolytic capacitor (10µF,}
u _{450V), in order to bypass the parasitic inductance present in the connection wires between the DC}
d _{supply voltage and the board (see figure 24).}
Pro _{Figure 24: Connection between the DC supply voltage and the board}
t(s) ^{- Obsolete} _{DC Power Supply}
VK06 Demoboard
olete ^Produc _{All the measurements have been done supplying the converter with 400V DC.}
Obs4.4.1 START-UP PHASE
In figure 25 the start-up phase is shown. The voltages on the low side (LS) V_CC and diac pins are
reported.
It is possible to notice that the V_CC voltage reaches its clamp value (~6.8V) before the diac strike. In
figure 26 the first oscillation cycles after the diac strike are shown.
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