EVL6563S-400W STMicroelectronics, EVL6563S-400W Datasheet - Page 13

• Manufacturer Part Number: EVL6563S-400W
• Description: EVAL BOARD FOR L6563(400W)
• Manufacturer: STMicroelectronics
• Type: Motor / Motion Controllers & Driversr

Specifications of EVL6563S-400W

• Main Purpose: Power Management, Power Factor Correction
• Embedded: No
• Utilized Ic / Part: L6563
• Primary Attributes: 400W Power Factor Correction and Preregulator Combination
• Secondary Attributes: Transition Mode & Active Tracking Boost Function.
• Maximum Operating Temperature: + 60 C
• Product: Power Management Development Tools
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: L6563S
• Other names: 497-10488

AN2994
Figure 19. EVL6563S-400W inductor current
CH1: Q1/Q2 drain voltage
CH2: MULT voltage - pin #3
CH4: L4 inductor current ripple envelope
On both the drain voltage traces reported in
crossing points of the sine wave it is possible to note the action of the THD optimizer
embedded in the L6563S. This optimizer is a circuit that minimizes the conduction’s dead-
angle occurring at the AC’s input current near the zero-crossings of the line voltage
(crossover distortion). In this way, the THD of the current is considerably reduced. A major
cause of this distortion is the inability of the system to transfer energy effectively when the
instantaneous line voltage is very low. This effect is magnified by the high-frequency filter
capacitor placed after the bridge rectifier, which retains some residual voltage that causes
the diodes of the bridge rectifier to be reverse-biased and the input current flow to
temporarily stop. To overcome this issue, the device forces the PFC pre-regulator to process
more energy near the line voltage’s zero-crossing, as compared to that commanded by the
control loop.
This results in minimizing the time interval where energy transfer is lacking and fully
discharging the high-frequency filter capacitor after the bridge. Essentially, the circuit
artificially increases the ON time of the power switch with a positive offset added to the
output of the multiplier in the proximity of the line voltage zero crossing. This offset is
reduced as the instantaneous line voltage increases, so that it becomes negligible as the
line voltage moves towards the top of the sinusoid, and it is modulated by the voltage on the
V
is typically quite good, and a larger offset at high lines, where the energy transfer gets
worse.
To get the maximum benefit from the THD optimizer circuit, the high-frequency filter
capacitors after the bridge rectifier should be minimized, compatibly with EMI filtering needs.
A large capacitance, in fact, introduces a conduction dead-angle of the AC input current in
itself, thus reducing the effectiveness of the optimizer circuit.
ripple envelope at 230 Vac, 50 Hz,
full load
FF
pin so as to have little offset at low lines, where the transfer of energy at zero crossings
Doc ID 15796 Rev 2
Figure 20. EVL6563S-400W inductor current
CH1: Q1/Q2 drain voltage
CH2: MULT voltage - pin #3
CH4: L4 inductor current ripple envelope
Figure 18
Test results and significant waveforms
ripple (detail) at 230 Vac, 50 Hz,
full load
and
Figure
20, close to the zero
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