EVAL6599-90W STMicroelectronics, EVAL6599-90W Datasheet - Page 14

• Manufacturer Part Number: EVAL6599-90W
• Description: EVAL BOARD FOR L6599
• Manufacturer: STMicroelectronics
• Type: Power Factor Correctionr

Specifications of EVAL6599-90W

• Main Purpose: AC/DC, Primary Side and PFC
• Outputs And Type: 1, Isolated
• Power - Output: 90W
• Voltage - Output: 19V
• Current - Output: 4.7A
• Voltage - Input: 90 ~ 264VAC
• Regulator Topology: Resonant
• Frequency - Switching: 90kHz
• Board Type: Fully Populated
• Utilized Ic / Part: L6563, L6599
• Input Voltage: 90 V to 264 V
• Output Voltage: 19 V
• Dimensions: 78 mm x 174 mm
• Product: Power Management Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: L6599
• Other names: 497-5497

Test results
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set by the divider R11, R12, R13, R28. As soon as it reaches the L6599 LINE pin threshold,
the resonant starts to operate. Hence the output voltage rises according to the soft-start and
reaches the nominal level. This sequence provides for the advantages of a perfect
sequencing of the circuit at start-up with the PFC acting as master and avoids complex
additional circuitry for the correct start-up of the circuit in all conditions. The circuit has been
tested in all line and load conditions showing a correct start-up sequence. The used high
voltage start-up circuit used avoids useless power dissipation during light load operation and
provides for an almost constant wake-up time of the circuit.
In
enables the operation of the L6599 converter's soft start-up sequence is triggered therefore
initially, the capacitor C18 is totally discharged, and the resistor R44 is effectively in parallel
to R24 thus the resulting initial frequency is determined by R
optocoupler's phototransistor is off (as long as the output voltage is not too far away from the
regulated value). C18 is progressively charged until its voltage reaches the reference
voltage (2 V) and, consequently, the current through R44 goes to zero.
During this frequency sweep the operating frequency will decrease following the exponential
charge of C18 that will count balance the non-linear frequency dependence of the tank
circuit. As a result, the average input current will smoothly increase, without the peaking that
occurs with linear frequency sweep, and the output voltage will reach the regulated value
with almost no overshoot as the waveforms in the picture.
Figure
13, the L6599 start-up sequence is analyzed: as soon as the LINE pin (#7)
SS
and R
Fmin
only, since the
AN2321