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SPV1050

Functional description

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Functional description

The SPV1050 is an ultralow power energy harvester with an embedded MPPT algorithm,

a battery charger and power manager designed for applications up to about 400 mW.

The SPV1050 device integrates a DC-DC converter stage that can be configured as boost

or buck-boost by tying the CONF pin to PV+/TEG+ or to ground respectively as shown in

Figure 4

and Figure 12 on page 20.

If the embedded MPPT algorithm is enabled, the device regulates the working point of the

DC-DC converter in order to maximize the power extracted from the source by tracking its

output voltage. See further details in Section 6.2: Boost configuration on page 16 and

Section 6.3: Buck-boost configuration on page 20

.

The MPPT algorithm can be disabled by shorting the MPP-SET pin to the STORE pin, and

by providing an external voltage to the MPP-REF pin.

In case of low impedance source (e.g. USB), the MPP-REF must be connected to GND.

triggered.

In case of high impedance source with limited current capability (i.e. if the source is unable

to sustain switching at the maximum duty cycle), the MPP-REF pin must be connected to a

through a resistor ladder connected to STORE or any other voltage reference available in

the application.

If the MPP pin is connected to the source by a resistor ladder, then the same consideration

must be extended to the MPP pin. Referring to Figure 19 (where connections between

MPP-SET to R2-R3 must be open and MPP-SET must be considered as connected to

STORE):

–

6.1

Battery charger

In order to guarantee the lifetime and safety of the battery, the SPV1050 device controls an

integrated pass transistor between the STORE and BATT pins and implements both the

undervoltage (UVP) and the end-of-charge (EOC) protection thresholds.