EVAL6599-400W-S STMicroelectronics, EVAL6599-400W-S Datasheet - Page 17

• Manufacturer Part Number: EVAL6599-400W-S
• Description: DEMO BOARD FOR L6599
• Manufacturer: STMicroelectronics
• Type: Power Factor Correctionr

Specifications of EVAL6599-400W-S

• Main Purpose: AC/DC, Primary Side and PFC
• Outputs And Type: 3, Isolated
• Power - Output: 400W
• Voltage - Output: 200V, 5V, 3.3V
• Current - Output: 2A, 1A, 700mA
• Voltage - Input: 90 ~ 264VAC
• Regulator Topology: Resonant
• Board Type: Fully Populated
• Utilized Ic / Part: L6563, L6599
• Input Voltage: 90 V to 264 V
• Output Voltage: 3.3 V to 200 V
• Dimensions: 132 mm x 265 mm
• Product: Power Management Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: L6599
• Other names: 497-5856

AN2492
2.6
activated that shuts down the device and, in case of continuous overload/short circuit,
results in continuous intermittent operation with a user-defined duty cycle. This function is
accomplished by the DELAY pin 2 of the resonant controller, by means of the capacitor C24
and the parallel resistor R37 connected to ground. As the voltage on the ISEN pin exceeds
0.8V, the first OCP comparator, in addition to discharging CSS, turns on an internal current
generator that via the DELAY pin charges C24. As the voltage on C24 reaches 3.5 V, the
L6599 stops switching and the internal generator is turned off, so that C24 will now be slowly
discharged by R37. The IC will restart when the voltage on C24 becomes less than 0.3 V.
Additionally, if the voltage on the ISEN pin reaches 1.5 V for any reason (e.g. transformer
saturation), the second comparator will be triggered, the device will shut down and the
operation will be resumed after an on-off cycle.
protection sequence described above. The on-off operation is controlled by the voltage on
pin 2 (DELAY), providing for the hiccup mode of the circuit. Thanks to this control pin, the
designer can select the hiccup mode timing and thus keep the average output current at a
safe level.
Figure 18. +200 V output short-circuit waveforms
Overvoltage protection
Both the PFC pre-regulator and the resonant converter are equipped with their own
overvoltage protection circuit. The PFC controller is internally equipped with a dynamic and
a static overvoltage protection circuit sensing the current flowing through the error amplifier
compensation network and entering in the COMP pin (#2). When this current reaches about
18 µA, the output voltage of the multiplier is forced to decrease, thus reducing the energy
drawn from the mains. If the current exceeds 20 µA, the OVP is triggered (Dynamic OVP),
and the external power transistor is switched off until the current falls approximately below 5
µA. However, if the overvoltage persists (e.g. in case the load is completely disconnected),
the error amplifier will eventually saturate low, triggering an internal comparator (Static OVP)
that will keep the external power switch turned off until the output voltage comes back close
to the regulated value. Moreover, in the L6563 there is additional protection against loop
failures using an additional divider (R5, R7, R9, R16 and R25) connected to a dedicated pin
(PFC_OK, Pin 7) protecting the circuit in case of loop failures, disconnection, or deviation
from the nominal value of the feedback loop divider. Hence the PFC output voltage is always
Figure 18.
illustrates the short-circuit
Ch1: half-bridge voltage on pin
14
Ch2: + 200 V output current
Ch3: pin 6 (ISEN)
Ch4: pin 2 (DELAY)
Electrical test results
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