EVL170W-FTV STMicroelectronics, EVL170W-FTV Datasheet - Page 19

• Manufacturer Part Number: EVL170W-FTV
• Description: DEMO BOARD VIPER27 L6599A L6564
• Manufacturer: STMicroelectronics
• Series: VIPER™r

Specifications of EVL170W-FTV

• Main Purpose: Power Supply with PFC
• Outputs And Type: 2, Isolated
• Power - Output: 170W
• Voltage - Output: 24V, 12V, 5V
• Current - Output: 6A, 2A, 2A
• Voltage - Input: 90 ~ 264VAC
• Regulator Topology: Flyback
• Frequency - Switching: 130kHz
• Board Type: Fully Populated
• Utilized Ic / Part: Viper27LN, L6564, L6599A
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 497-11254

AN3329
Figure 31. PFC Vds and inductor current at
Figure 33. L6564 signals-1 at 115 Vac - 60 Hz,
CH1: Q1 drain voltage
CH1: GD (pin #9)
CH3: CS (pin #4)
CH3: MULT (pin #3)
L6564 signals are shown in
Figure 35
a line half-period at 115 Vac and 230 Vac respectively. Voltage feed-forward compensates
for the gain and crossover frequency variation with the line voltage, since the power stage
gain of PFC pre-regulators varies with the square of the RMS input voltage. Therefore, a DC
voltage equal to the peak of the MULT (#3) pin is derived on the VFF (#5) pin and fed into a
square/divider circuit making the COMP signal almost line-independent and improving the
dynamic behavior. That is emphasized in
(#3) pin at the peak of the line voltage matching that on the VFF pin.
230 Vac - 50 Hz, full load
full load
shows voltages on the VFF (#5), CS (#4), COMP (#2), and MULT (#3) pins along
CH2: MULT (pin #3)
CH4: L1 inductor current
CH2: ZCD (pin #7)
CH4: CS (pin #4)
Figure 33
Doc ID 18376 Rev 1
and
Figure 32. PFC Vds and inductor current at
Figure 34. L6564 signals-2 at 115 Vac - 60 Hz,
CH1: Q1 drain voltage
CH1: GD (pin #9)
CH3: CS (pin #4)
CH3: MULT (pin #3)
Figure
34
for reference.
36, which illustrates voltage on the MULT
230 Vac - 50 Hz, full load - detail
full load
CH4: L1 inductor current
CH4: CS (pin #4)
CH2: MULT (pin #3)
CH2: ZCD (pin #7)
Functional check
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