Power supply consumption
UM1631
12/27
DocID024503 Rev 1
5
Power supply consumption
5.1
Max. output current and standby consumption
Non-isolated SMPS based on the VIPer16 in buck-boost topology is designed to provide
output voltage of -6 V. Maximum output current is 120 mA. -3.3 V voltage supply necessary
to supply MCU consists of linear regulator LM337.
Standby consumption has been measured in full range of the supply voltage. The standby
power consumption fulfills the requirement of maximum total power consumption to be
below 500 mW.
Total power consumption of the board in standby mode at supply voltage of 264 Vrms/50 Hz
was 499 mW (output current 10 mA at output voltage -6 V).
The power supply uses mains voltage for self supply from high voltage current generator.
Standby power consumption can be reduced by using the configuration with VIPer16 supply
made from the low voltage side. Refer to the AN2872 application note and VIPer16
datasheet for further information on power supply design.
5.2
Gate voltage impact on gate current
Gate voltage V
GT
varies with load current as shown in
?. This variation is
significant and cannot be neglected mainly for devices that are controlled in DC mode and
with low power supply level such as 3.3 V.
Figure 6. Example of V
GT
variation with load current in quadrants 2 and 3
(0.2 A RMS) for a Z0103 (T
j
= 85 °C, I
G0
= 7.5 mA)
