DocID022816 Rev 2

11/19

AN4050

Reference design description

4

Reference design description

The set-up environment used for the measurement campaign is shown below.

Figure 12. Application set-up

A solar array simulator (SAS, SAS-FL05/01 from CBL Electronics) to simulate the PV

module with Voc = 2.5 V, Isc = 210 mA, Vmp = 2.0 V, Imp = 200 mA (@ 1000 W/m

2

irradiance) and a Li-Ion battery 3.7 V-700 mAh, are used.

Figure 13 shows the I-V and P-V

curves generated by the SAS, obtained using a PV module analyzer (ISM490 from ISO-

TECH):

Figure 13. V-I and P-V plot diagrams

Figure 14 and 15 show the partial and full charge curves respectively. The “partial charge”

curve shows charge current and voltage within a one hour time frame at full irradiation

starting from 3.4 V condition. The “full charge” curve shows charge current and voltage until

the fully charged status is triggered, starting from a 3.4 V condition. After the one hour

charge period time, the battery voltage reaches 3.8 V.

Different results can be obtained if a different PV panel and/or battery are used. If any help

is required regarding the use of different PV panels and/or batteries, please go to the

support area at www.st.com.

The average overall power efficiency is ~85% (94% for SPV1040 and 90% for L6924D).