AN3971

Optimizing the energy from the panel

Doc ID 022119 Rev 2

9/28

Figure 7.

System architecture

The SPV1020 only implements an interleaved 4-boost converter, causing a voltage increase

from input to output, so in order to charge a lead acid battery, it is mandatory to use a panel

with Voc <= V_batt_min, just to keep a step-up voltage configuration.

If a 12 V battery charging is needed, it is necessary to add an additional buck stage to the

system, in order to decrease the output voltage from STEVAL-ISV005V2 higher than

Vbatt_min. A generic schematic may be that in the image below:

Figure 8.

Architecture with DC-DC buck converter (for 12 V batteries)

R18

R19

R9

Vctrl

Vin_sns

SPV1020

PV +

R1

R2

PV -

R17

SEA05

PZ_Out

Vout_sns

Vbatt +

Vbatt -

AM10277V1

AM10278V1

SPV1020

DC/DC

Buck

converter

VOUT

Feedback Pin

SEA05

OUT

VCTRL

GND

Ipv

Ibatt

Energy Flow