EVL170W-FTV STMicroelectronics, EVL170W-FTV Datasheet - Page 14

• 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

Functional check
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Figure 15. Standby supply waveforms at
Figure 17. Standby supply 5 V ripple at
CH1: DRAIN (pin #8)
CH3: CONT (pin #3)
CH3: + 5 V standby ripple voltage
In
115 Vac of the standby converter only. Ripple and noise measured at full load are very
limited.
Figure 18
and full load. At Viper27LN power-on the Vcc capacitor is charged by the internal startup
current source until its voltage reaches the turn-on threshold. At this point the Viper27LN
starts operating and the output voltage rises to reach the nominal value. During the
converter startup, the Viper27LN internal digital fixed time-based (8.5 ms) soft-start
gradually increases the drain current to its maximum value. In this way the stress on the
secondary diode is considerably reduced and transformer saturation is prevented. The
brownout circuit prevents the Viper27LN from starting up during abnormal mains conditions.
400 Vdc, full load
115 Vac - 60 Hz, full load
Figure 17
shows the waveforms during the startup of the standby converter only, at 115 Vac
CH2: V
CH4: FB (pin #4)
the 5 V standby output voltage ripple has been captured during operation at
DD
(pin #2)
Doc ID 18376 Rev 1
Figure 16. Standby supply output rectifiers
Figure 18. Standby supply startup at 115 Vac -
CH3: PIV D22
CH1: DRAIN (pin #8)
CH3: BO (pin #5)
PIV at 400 Vdc, full load
60 Hz, full load
CH4: PIV D18
CH2: +5 V standby
CH4: V
DD
(pin #2)
AN3329