AN3971 datasheet(13/28 Pages) STMICROELECTRONICS

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AN3971

External component selection

Doc ID 022119 Rev 2

13/28

External component selection

The STEVAL-ISV005V2 is based on two ST key devices: the SPV1020 and SEA05.

In order to perform properly, both the SPV1020 and SEA05 require different application

components whose selection depends on the electrical characteristics of the PV panel and

of the battery.

The electrical characteristics of the PV panel limit the selection of the application

components of the SPV1020. Please refer to the SPV1020 datasheet.

In order to properly define the application components for the SEA05, the user should

simply define the following parameters:

●

Output resistor partitioning (R7/R8) according to the SEA05 internal voltage control

threshold, to control the maximum overvoltage battery protection

●

Sensing resistor (Rsns: R9 and/or R10) in the PV-loop, to control the maximum

overcurrent battery protection, according to the internal current threshold

●

The PV panel must be selected in order to guarantee the SPV1020 functionality; and

so, in order to respect the SPV1020 step-up conditions, the Voc of the PV panel must

be lower than Vbat_min (voltage when the battery is deeply discharged).

The STEVAL-ISV005V2 application example has been developed for the following features:

SLA battery: Vbatt_nom = 24 V & C = 4 Ah

PV panel: Vmp = 18 V & Voc = 20 V, Imp = 1.6 A & Isc = 2 A

So the SEA05 IC must limit at the following voltage and current:

Vbatt_max = (24 * 1.2) V = 28.8 V

Ibatt_max = (4/4) A = 1 A

Figure 12.

System architecture SPV1020 + SEA05

AN3971 Folha de dados(PDF) 13 Page - STMicroelectronics