Application information

VIPer0P

28/36

DocID028423 Rev 2

5.2

Example of ZPM management using MCU

Sometimes the SMPS provides a -5 V bus for instance to enable triac driving to control the

motor of a washing machine. In this case, not to generate an additional +5 V bus, the

ground of the MCU can be connected to the -5 V bus and its positive supply voltage to the

ground of SMPS and VIPer0P. This connection requires an interface circuit realizing a level

shifting to properly drive ON and OFF, like the one shown in the Figure 39: "Example of

interfacing the VIPer0P to a MCU supplied from a negative rail ". During ZPM the MCU is

supplied through ON, but a linear regulator is needed in between, in order to avoid that

during normal operation the AMR of the MCU is exceeded.

Figure 39: Example of interfacing the VIPer0P to a MCU supplied from a negative rail

5.3

Energy saving performances

VIPer0P allows designing applications compliant with the most stringent energy saving

regulations. In order to show the typical performances achievable, the active mode average

efficiency and the efficiency at 10% of the rated output power of a single output flyback

converter using VIPer0P have been measured and are reported in Table 9. In addition,

ZPM, no-load and light load consumptions are shown in the below tables and Figure 40:

"PIN versus VIN in ZPM and no load" and Figure 41: "PIN versus VIN in light load".

10% output load efficiency [%]

Active mode average efficiency [%]

78.0

80.9

71.1

81.0

0 V

-5 V

EAGND

GND

ON

OFF

VCC

GND

GPIO

220 pF

56 k

W

MCU

VIPer0P

220 pF

GPIO

56 k

W

LDO

GIPD250820151541FSR