TN0024 Datasheet, PDF (9/11 Pages) STMicroelectronics – Power supply HOLD-UP time

TN0024
Figure 5. Measured voltage vs. time
VIPer53DIP-E (see Figure 4)
Time (5 ms/div)
Orange: Bulk capacitor voltage (20 V/div)
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VIPer53DIP-E (see Figure 4)
The VIPer53DIP-E has a state-of-the-art, enhanced current mode PWM circuit combined
with an optimized avalanche rugged high voltage MDMesh Power MOSFET in the same
package. The VIPer53DIP-E used for this application has an R_ds(on) of 1.0 Ω, a peak current
of 1.7 A, a drain to source voltage rating of 620 V and is capable of 30 W for a wide voltage
range input voltage in the discontinuous flyback mode. It also has an overload delay at
TOVL controlled by an external capacitor.
The TOVL function is well suited for various length power line drop conditions which could
cause damage or overheating to the power supply. An external capacitor, C6, is used to
delay the overload protection to meet the designed HOLD-UP time specification and then
protect the power supply while entering an endless restart sequence. The VIPer53DIP-E
resumes normal switching immediately after the line voltage returns to the power supply
designed input voltage.
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