AN3432 datasheet(19/24 Pages) STMICROELECTRONICS

Part #	AN3432

Description	How to choose a bypass diode for a silicon panel junction box

PDF	24 Pages

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Manufacturer	STMICROELECTRONICS [STMicroelectronics]

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19 / 24 page

AN3432

Application constraints

Doc ID 019041 Rev 1

19/24

3.2.2

200 cycles

This test is requested for the crystalline silicon terrestrial photovoltaic modules design

qualification. It is described in the standard EN61215 paragraph 10.11.

The bypass diode is polarized in reverse when the module temperature is above 25 °C.

Figure 15 illustrates the test conditions.

Figure 15.

200 cycles test conditions

As the diode is in reverse, the junction temperature is very close to the ambient temperature

due to low reverse losses. So there is no risk to exceed maximum junction temperature. The

critical parameter in this test is the value of voltage when Tamb = 25 °C. Actually, the reverse

voltage of a diode decreases with the temperature and then the diode VRRM (25 °C) is the

higher value and needs to meet the following requirement:

For an ST Schottky diode, the VRRM is guaranteed at 25 °C.

Ipeak

Minimum

time 10 min.

Minimum

time 10 min.

Maximum cycle time

100 °C/h max.

Time h

-40

+25

+85

VRRM(25 °C) > VR(25 °C)

AN3432 Datasheet(PDF) 19 Page - STMicroelectronics