SPV1040

Detailed description

Doc ID 18080 Rev 3

11/15

6.5

Constant current regulation

The constant current control loop consists of an op amp and an external sense resistor that

feeds the current sensing circuit with a voltage proportional to the DC output current. This

resistor determines the current regulation set-point and must be adequately rated in terms

of power dissipation. It provides the capability to fix the maximum output current to protect

the battery.

6.6

Overcurrent protection (OVC)

When the current that flows through the inductor reaches 1.8 A (overcurrent shutdown limit),

the N-channel power switch is immediately forced OFF and the P-channel synchronous

rectifier is switched ON. Once the overcurrent condition has expired (the inductor current

goes below 1.8 A) the N-channel power switch is turned back ON.

6.7

Overtemperature protection (OVT)

When the temperature sensed at silicon level reaches 155 °C (overtemperature shutdown

limit), the N-channel power switch is immediately forced OFF and the P-channel

synchronous rectifier is switched ON. The device becomes operative again as soon as the

silicon temperature goes below 130 °C.

6.8

Shutdown mode

The XSHUT pin low shuts OFF all internal circuitry, achieving the lowest power consumption

mode.

6.9

Undervoltage lockout (UVLO)

In order to prevent batteries from over-discharging, the device turns OFF in case of MPP-

SET voltage lower than 0.24 V (no irradiation). A hysteresis has been implemented to avoid

unpredictable ON-OFF switching.

6.10

Reverse polarity

In order to avoid damage to the device and battery discharge when the solar panel

connection is reverse-inserted, a dedicated protection circuit has been implemented. In

such condition, the SPV1040 stays OFF until the panel is inserted correctly.