EVALVIPER17H-6W STMicroelectronics, EVALVIPER17H-6W Datasheet - Page 17

• Manufacturer Part Number: EVALVIPER17H-6W
• Description: BOARD EVAL FOR VIPER17H
• Manufacturer: STMicroelectronics
• Series: VIPER™r

Specifications of EVALVIPER17H-6W

• Main Purpose: AC/DC, Primary Side
• Outputs And Type: 1, Isolated
• Power - Output: 6W
• Voltage - Output: 12V
• Voltage - Input: 85 ~ 265VAC
• Regulator Topology: Flyback
• Frequency - Switching: 115kHz
• Board Type: Fully Populated
• Utilized Ic / Part: VIPer17
• Product: Power Management Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-6446

VIPER17
7.4
7.5
Power down operation
At converter power down, the system loses regulation as soon as the input voltage is so low
that the peak current limitation is reached. The V
the V
energy transfers to the IC interrupted and consequently the V
Figure 23 on page
the start up sequence is inhibited and the power down completed. This feature is useful to
prevent converter’s restart attempts and ensures monotonic output voltage decay during the
system power down.
Auto restart operation
If after a converter power down, the V
is not inhibited and will be activated only when the V
V
generator restarts the V
V
fault condition. After a fault condition, the charging current, I
the 3 mA (typ.) of a normal start up converter phase. This feature together with the low
V
long repetition rate and the converter works safely with extremely low power throughput.
The
Figure 25. Timing diagram: behavior after short circuit
DD(RESTART)
DD(RESTART)
DD(RESTART)
Figure 25
DDoff
threshold (see
. The scenario above described is for instance a power down because of a
threshold (see
threshold ensures that, after a fault, the restart attempts of the IC has a very
shows the IC behavioral after a short circuit event.
16. Later, if the V
DD
Table 7 on page
capacitor charging only when the V
Table 7 on page
Doc ID 14419 Rev 7
IN
IN
is lower than V
is higher than V
6) the power MOSFET is switched OFF, the
6). This means that the HV start up current
DD
voltage drops and when it falls below
DD
DRAIN_START
voltage drops down the
DRAIN_START,
DDch
DD
DD
, is 0.6 mA (typ.) instead of
voltages decreases,
voltage drops below
(see
Operation descriptions
the start up sequence
Table 7 on page
17/31
6),