VIPER0PHDTR datasheet(18/36 Pages) STMICROELECTRONICS

18 / 36 page

General description

VIPer0P

18/36

DocID028423 Rev 2

At the nominal input voltage, 230 VAC, the typical consumption (RG = 34

MΩ) is 3.2 mW and

the worst-case consumption (RG

= 28 MΩ) is 3.9 mW.

When the IC is disconnected from the mains, or there is a mains interruption, for some time

the converter will keep on working, powered by the energy stored in the input bulk

capacitor. When this is discharged below a critical value, the converter is no longer able to

keep the output voltage regulated. During the power down, when the DRAIN voltage

becomes too low, the HV current source (IHV) remains off and the IC is stopped as soon as

the VCC drops below the UVLO threshold, VCCoff.

Figure 26: Power-ON and power-OFF

4.5

Soft startup

The internal soft-start function of VIPer0P progressively increases the cycle-by-cycle

current limitation set point from zero up to IDLIM in 8 steps of 50 mA each. The soft-start

time, tSS, is internally set at 8 ms. This function is activated at any attempt of converter

start-up and at any restart after a fault event. The feature protects the system at the startup

when the output load presents itself like a short-circuit and the converter would work at its

maximum drain current limitation.

VIPER0PHDTR 数据表(PDF) 18 Page - STMicroelectronics