Datasheet

Functional check AN3329
22/47 Doc ID 18376 Rev 1
Figure 39. Output rectifiers PIV waveforms
No load operation
In Figure 40 and 41 operation at no load is shown. This check has been done for reference
only, as typically a TV SMPS never works in such conditions. As seen, PFC is working in
burst-mode, while the resonant stage is operating in continuous switching. This is possible
by connecting the standby pin to the RFmin pin and it has been done to avoid any possible
interference between the resonant stage and the TV circuitry. In Figure 41 the half bridge
maximum operating switching frequency is measured.
CH2: D11 anode voltage
CH3: D9A anode voltage
CH4: D9B anode voltage
CH1: D4 anode voltage
Figure 40. No load operation at 115 Vac - 60 Hz Figure 41. No load operation at 115 Vac - 60 Hz
- L6599A signals
CH4: PFC drain voltage
CH1: HB voltage
CH3: Standby (pin #5)
CH1: HB voltage
CH2: CF (pin #3)