L6563ATR STMicroelectronics, L6563ATR Datasheet - Page 22

• Manufacturer Part Number: L6563ATR
• Description: IC PFC CTRLR TRANSITION 14SOIC
• Manufacturer: STMicroelectronics

Specifications of L6563ATR

• Mode: Discontinuous (Transition)
• Current - Startup: 50µA
• Voltage - Supply: 10.3 V ~ 22 V
• Operating Temperature: -25°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 14-SOIC (3.9mm Width), 14-SOL
• Maximum Operating Temperature: + 150 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 25 C
• For Use With: 497-9082 - EVAL BOARD L6563 (200W)497-8850 - BOARD EVAL FOR L6563/STW55NM60N497-8834 - BOARD DEMO FOR L6563/LL6566A497-8429 - BOARD ADAPTER L6599/STP12NM50N497-5854 - DEMO BOARD FOR L6563497-5496 - EVAL BOARD FOR L6599497-5493 - EVAL BOARD FOR L6563
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Frequency - Switching: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 497-6129-2

Application information
22/39
Figure 38. THD optimization: standard TM PFC controller (left side) and L6563/A
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-crossings.
This offset is reduced as the instantaneous line voltage increases, so that it becomes
negligible as the line voltage moves toward the top of the sinusoid. Furthermore the offset is
modulated by the voltage on the V
little offset at low line, where energy transfer at zero crossings is typically quite good, and a
larger offset at high line where the energy transfer gets worse.
The effect of the circuit is shown in
PFC controller are compared to those of this chip.
To take maximum benefit from the THD optimizer circuit, the high-frequency filter capacitor
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 -
even with an ideal energy transfer by the PFC pre-regulator - thus reducing the effectiveness
of the optimizer circuit.
Imains
Input current
(right side)
Rectified mains voltage
MOSFET's drain voltage
Input current
FF
Vdrain
Figure
pin (see
38, where the key waveforms of a standard TM
Section 6.3 on page 18
Imains
Input current
Rectified mains voltage
section) so as to have
MOSFET's drain voltage
Input current
L6563 - L6563A
Vdrain